−---
−title: Lighting Controls
−category: Electrical / Lighting
−toc_depth: 3
−description: >
− When to use: The building lighting control system for commercial, institutional, and industrial projects — the sensors, switches, dimmers, time switches, relay and contactor panels, photosensors, and networked or luminaire-level control equipment that turn lighting on, off, and to intermediate levels in response to occupancy, daylight, schedule, and manual command. Covers the control devices, the dimming and control interface to the luminaire driver (0–10V, DALI/DALI-2, phase-cut), networked and luminaire-level control systems, the emergency lighting control interface required by UL 924, the low-voltage control wiring, the documented sequences of operation, and the commissioning and functional testing the energy code requires.
− Not intended for: The luminaires themselves and their integral drivers and fixture-level dimming hardware (see [[sync/lighting-fixtures]]); exterior, site, and roadway lighting controls, photocontrols, and scheduling, which are covered with the exterior luminaires (see [[sync/exterior-lighting]]); the emergency and standby power sources, inverters, transfer equipment, and the egress illumination design itself (see [[sync/emergency-and-standby-power]]); integration of lighting into a building-wide control and monitoring network beyond the lighting control system's own gateway (see [[sync/building-automation-system]]); and wall switches and dimmers furnished as ordinary wiring devices where no automatic control is provided (see [[sync/wiring-devices]]).
−---
−
−# Scope
−
−This specification covers the lighting control system — the devices and the logic that determine when and how much the building's lighting operates. It governs occupancy and vacancy sensors, photosensors for daylight response, time switches and astronomical schedules, manual switches and dimmers, relay and contactor panels, the dimming interface to the luminaire driver, networked and luminaire-level control systems, the emergency lighting control interface, the low-voltage control wiring, and the commissioning and functional testing that adopted energy codes require. The luminaires and their integral drivers are specified separately under [[sync/lighting-fixtures]]; this standard governs everything that tells those luminaires what to do.
−
−Lighting controls are not optional accessories. The adopted energy code — ANSI/ASHRAE/IES 90.1 or the International Energy Conservation Code (IECC), and in California the more stringent Title 24, Part 6 — mandates automatic shutoff, occupancy-based control, daylight-responsive control, and in many cases demand-responsive control for most interior spaces. A lighting installation that meets every photometric and power-density target but lacks compliant controls does not pass plan review and will not be accepted. The controls are therefore a code-compliance requirement first and an energy-savings and occupant-comfort feature second, and they are specified here as outcomes the system shall achieve rather than as a particular manufacturer's product family.
−
−This standard is organized from the general to the specific: the administrative requirements first, then the individual control devices, then the dimming and control interface to the luminaire, then networked and luminaire-level systems, then the documented sequences of operation, then the installation and low-voltage wiring, and finally the commissioning and functional testing that closes out the work. The control intent — which spaces are controlled how, where sensors and switches are located, and how zones are bounded — is project-specific and is established on the contract drawings; this standard provides the framework, performance, and quality requirements that make those drawings buildable and compliant.
−
−The emergency lighting control interface is addressed here because the lighting control system must not be allowed to extinguish egress lighting. Where lighting on the egress path is switched, dimmed, or otherwise controlled, the control of that lighting shall be overridden to full output on loss of normal power through equipment listed to UL 924, in accordance with NFPA 70 (National Electrical Code) Article 700. The emergency and standby power sources, the inverters and transfer equipment, and the egress illumination design itself are outside this standard and are coordinated under [[sync/emergency-and-standby-power]].
−
−# Referenced Standards
−
−Equipment, materials, and installation shall comply with the latest adopted edition of the following standards and codes. Where the contract documents, the adopted building or energy code, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
−
−| Standard | Title |
−|----------|-------|
−| UL 924 | Emergency Lighting and Power Equipment |
−| UL 916 | Energy Management Equipment |
−| UL 508 | Industrial Control Equipment |
−| UL 2043 | Fire Test for Heat and Visible Smoke Release for Discrete Products in Air-Handling Spaces |
−| NFPA 70 | National Electrical Code (Articles 700 — Emergency Systems; 725 — Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits; 410 — Luminaires) |
−| NFPA 101 | Life Safety Code |
−| ANSI/ASHRAE/IES 90.1 | Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
−| IECC | International Energy Conservation Code (Commercial Provisions, Section C405 — Electrical Power and Lighting Systems) |
−| California Title 24, Part 6 | California Building Energy Efficiency Standards |
−| ANSI C137.1 | Lighting Systems — 0–10V Dimming Interface for LED Drivers, Fluorescent Ballasts, and Controls |
−| ANSI C137.3 | Lighting Systems — Minimum Requirements for Installation of Energy Efficient Power Sources for Use with Light Emitting Diode Drivers |
−| ANSI C137.4 | Lighting Systems — Digital Interface with Auxiliary Power |
−| IEC 62386 | Digital Addressable Lighting Interface (DALI / DALI-2 / D4i) |
−| NEMA WD 7 | Occupancy Motion Sensors Standard |
−| NEMA 410 | Performance Testing for Lighting Controls and Switching Devices with Electronic Drivers and Discharge Ballasts (Inrush Current) |
−| FCC Part 15 | Radio Frequency Devices (for wireless control nodes) |
−
−DesignLights Consortium (DLC) Networked Lighting Control (NLC) and Luminaire Level Lighting Control (LLLC) qualified-products lists are utility-incentive programs, not consensus standards; where this standard references them it references the program's published technical requirements as a procurement screen, not as a code requirement. The energy code in force in the project jurisdiction governs; the Engineer shall confirm which code and edition the authority having jurisdiction has adopted, because the control requirements differ materially between ASHRAE 90.1, the IECC, and Title 24.
−
−# Submittals
−
−## Action Submittals
−
−Contractor shall submit the following for the Engineer's review prior to procurement. A bill of devices alone is not a sufficient submittal; the system shall be documented well enough to confirm it implements the required sequences of operation and satisfies the adopted energy code.
−
−- Product data for each control device type — occupancy/vacancy sensors, photosensors, time switches, manual switches and dimmers, relay/contactor panels, network controllers, gateways, and power packs — including coverage patterns, ratings, and the dimming interface supported
−- A control system narrative and point-to-point wiring diagrams showing every device, its zone assignment, its power source, and its connection to the luminaire driver
−- A written sequence of operations for each space type, describing the response to occupancy, vacancy, daylight, schedule, manual override, and loss of normal power
−- A zoning and device-location plan reconciled against the reflected ceiling plan and the lighting plan
−- For networked systems, the network architecture, addressing scheme, gateway and integration points, and the commissioning and programming plan
−- For emergency lighting control, UL 924 listing documentation for each automatic load control relay, emergency control unit, or shunt device, and a diagram showing how each controlled egress luminaire is forced to full output on loss of normal power
−- A commissioning and functional-test plan describing how each required control function will be demonstrated and documented
−
−```datasheet
−label: Action Submittals Required
−type: checkbox
−options:
− - "Product data for each control device type"
− - "Control system narrative and point-to-point wiring diagrams"
− - "Written sequences of operation by space type"
− - "Zoning and device-location plan"
− - "Network architecture and commissioning/programming plan"
− - "UL 924 documentation for emergency control devices"
− - "Commissioning and functional-test plan"
−default: "Product data for each control device type"
−```
−
−## Closeout Submittals
−
−Contractor shall provide the following at substantial completion.
−
−- Operation and maintenance data for each device and for the network controller, including the configuration and programming software where applicable
−- As-built control drawings, sequences of operation, and the final zone and device schedule reflecting installed conditions
−- The completed and signed functional-test (acceptance-test) documentation required by the adopted energy code, with the date, result, and tested setpoints for each control function
−- The final programmed settings — time-of-day schedules, occupancy time delays, daylight setpoints, dimming levels, and demand-response levels — recorded so the Owner can restore them after a controller replacement
−- Training records for the Owner's operating staff
−- For self-testing emergency control devices, documentation of the initial automatic test result
−
−# Quality Assurance
−
−## Listing and Labeling
−
−Control devices shall be listed and labeled by a Nationally Recognized Testing Laboratory for the application in which they are installed — energy management equipment to UL 916, industrial control equipment such as relay and contactor panels to UL 508, and emergency lighting control devices to UL 924. An unlisted control device shall not be installed regardless of its apparent quality, because the listing is what establishes the device's voltage, current, and environmental ratings and its fitness for the circuit it controls.
−
−## Plenum-Rated Devices
−
−```datasheet
−label: Plenum-Rated Devices Required
−type: radio
−options:
− - "Not required (devices not in air-handling plenums)"
− - "Required for devices installed in air-handling plenums (UL 2043)"
−default: "Required for devices installed in air-handling plenums (UL 2043)"
−```
−
−Control devices and power packs installed above an accessible ceiling that serves as an air-handling plenum shall be listed to UL 2043 for fire and smoke release, because devices in the plenum airstream contribute to smoke loading in a fire and an unlisted device is a code violation in that location. Most commercial ceilings return air through the plenum, so plenum-rated devices are the common case.
−
−## Manufacturer System Compatibility
−
−All components of a given control subsystem — sensors, controllers, dimmers, and the network — shall be from a compatible product family confirmed by the manufacturer to interoperate, or shall be certified to an open interoperability standard such as DALI-2 (IEC 62386). Mixing devices that share only a nominal interface name but were never tested together is the most common cause of erratic dimming, failed daylight harvesting, and a system that cannot be commissioned; compatibility shall be confirmed at submittal, not discovered in the field.
−
−## Qualified Products Screening
−
−```datasheet
−label: Qualified Products Listing Required
−type: radio
−options:
− - "Not required"
− - "DLC Networked Lighting Control (NLC) listed"
− - "DLC Luminaire Level Lighting Control (LLLC) listed"
−default: "Not required"
−```
−
−Specifying a DLC NLC- or LLLC-listed system screens the controls against an independently verified set of capability and reporting requirements and is frequently a prerequisite for utility incentives, which can be substantial for networked controls. A DLC listing should be required where utility incentives are pursued; the Engineer shall confirm the specific qualified-products list referenced by the relevant utility program.
−
−# Energy Code Control Requirements
−
−The adopted energy code dictates the minimum control functions for each space, and these requirements drive most of the device selections that follow. The Engineer shall confirm the adopted code and edition, because the three dominant codes differ in their thresholds and prescriptions, and the design shall meet whichever governs the project.
−
−## Applicable Energy Code
−
−```datasheet
−label: Governing Energy Code
−type: select
−options:
− - "ANSI/ASHRAE/IES 90.1"
− - "IECC (International Energy Conservation Code)"
− - "California Title 24, Part 6"
− - "Other state or local energy code"
−default: "IECC (International Energy Conservation Code)"
−```
−
−The IECC and ASHRAE 90.1 are the predominant commercial energy codes across most US jurisdictions, and a project may comply through either where both are adopted. California Title 24 is materially stricter — it mandates more space types for occupancy and daylight control, prescribes specific acceptance tests, and requires those tests be performed by a certified acceptance-test technician — and where the project is in California, Title 24 governs and shall be confirmed as the basis of design.
−
−## Automatic Shutoff
−
−Interior lighting in each space shall be provided with an automatic means to shut the lighting off when the space is unoccupied, accomplished by occupancy sensing, a time-of-day schedule, or a combination, in accordance with the adopted energy code. A manual wall switch alone does not satisfy automatic shutoff. Where a time switch is the means of shutoff, an override that returns lighting for a limited period shall be provided so occupants working after hours are not left in the dark, and the override shall affect only a limited area so that one occupant does not light an entire floor.
−
−## Occupancy and Vacancy Control
−
−Spaces required by the energy code to have occupancy-based control shall reduce or extinguish lighting after the space is vacated within the time the code allows — generally not more than 20 minutes — and the controlled zone served by a single sensor shall not exceed the area the code permits, which the energy codes have progressively reduced. Certain space types, notably enclosed offices, conference and meeting rooms, classrooms, restrooms, and storage rooms, are specifically required to have occupancy or vacancy control; the required space types shall be taken from the adopted code.
−
−## Daylight-Responsive Control
−
−Lighting in daylit zones adjacent to windows (sidelit) and below skylights (toplit) shall be controlled by photosensors that reduce the electric lighting in response to available daylight, where the connected lighting load in the daylit zone exceeds the threshold the adopted code sets. The control shall dim the daylit lighting continuously and shall be capable of reducing it to the low level the code requires. Daylit zones that overlap shall be controlled together so that the controls do not fight one another.
−
−## Demand-Responsive Control
−
−```datasheet
−label: Automatic Demand-Responsive Control
−type: radio
−options:
− - "Not required"
− - "Required (large buildings per adopted energy code)"
−default: "Not required"
−```
−
−Where the adopted energy code requires it — typically for buildings above a floor-area threshold — the lighting control system shall be capable of receiving a demand-response signal and automatically reducing the total building lighting power by the percentage the code prescribes without manual intervention. Demand-responsive control is mandatory under Title 24 for qualifying buildings and is an option under ASHRAE 90.1 and the IECC; where required, the system's ability to accept the demand-response signal shall be confirmed and demonstrated.
−
−# Control Devices
−
−## Occupancy and Vacancy Sensors
−
−An occupancy sensor turns lighting on automatically when it detects presence and off after a vacancy delay (automatic-on). A vacancy sensor turns lighting on only by manual switch and off automatically after the space is vacated (manual-on, auto-off). The distinction is consequential for both energy and code compliance, because manual-on (vacancy) control saves more energy by never lighting a space that an occupant passes through without needing light, and several space types are specifically required to be manual-on.
−
−```datasheet
−label: Occupancy Control Mode
−type: radio
−options:
− - "Vacancy (manual-on, automatic-off)"
− - "Occupancy (automatic-on, automatic-off)"
− - "Partial-on (automatic to a reduced level, manual to full)"
−default: "Vacancy (manual-on, automatic-off)"
−```
−
−Vacancy (manual-on) control should be the default for private offices, conference rooms, classrooms, and similar enclosed spaces because it both saves the most energy and satisfies the manual-on requirement that several codes place on these spaces. Automatic-on control is appropriate for spaces where hands-free operation is important for safety or convenience, such as restrooms, corridors, and stairwells. Partial-on control automatically brings lighting to a reduced level on entry and requires a manual action for full output.
−
−```datasheet
−label: Sensor Detection Technology
−type: select
−options:
− - "Passive infrared (PIR)"
− - "Ultrasonic"
− - "Dual-technology (PIR + ultrasonic)"
− - "Microphonic / acoustic-assisted"
−default: "Dual-technology (PIR + ultrasonic)"
−```
−
−Passive infrared sensors detect the heat motion of an occupant and require an unobstructed line of sight; they are immune to false triggering from air movement but miss small motions and occupants behind partitions. Ultrasonic sensors detect motion by Doppler shift, fill a space around obstructions, and catch small motions such as typing, but can false-trigger on airflow from diffusers. Dual-technology sensors require both signals to turn lighting on and either to hold it on, which suppresses false-on and false-off and is the most reliable choice for the majority of enclosed spaces; it is the appropriate default. Single-technology sensors should be selected only where the space clearly favors one technology and cost is a concern.
−
−```datasheet
−label: Occupancy Vacancy Time Delay
−type: select
−unit: minutes
−options:
− - "5 minutes"
− - "10 minutes"
− - "15 minutes"
− - "20 minutes (code maximum)"
−default: "15 minutes"
−```
−
−The time delay is how long the sensor holds lighting on after it last detects occupancy. Too short a delay produces nuisance switching that annoys occupants and stresses the driver; too long wastes the energy the control is meant to save. A delay of about 15 minutes balances comfort against savings for most office and classroom use, and shall not exceed the maximum the adopted code permits.
−
−```datasheet
−label: Sensor Mounting / Coverage Type
−type: select
−options:
− - "Ceiling-mounted (360-degree)"
− - "Wall-switch replacement (integral to switch)"
− - "Wall/corner mounted (wide angle)"
− - "High-bay / aisle (long-throw)"
− - "Fixture-integral (luminaire-level)"
−default: "Ceiling-mounted (360-degree)"
−```
−
−The mounting type and coverage pattern shall match the geometry of the space so the entire occupied area is reliably detected without gaps or false triggers. Sensor type, location, and coverage shall be [[drawing: as indicated on the lighting control plan]]. A wall-switch occupancy sensor is economical for small enclosed rooms; ceiling sensors cover open areas; long-throw sensors suit warehouse aisles and high-bay spaces; and fixture-integral sensors are part of a luminaire-level control system addressed below.
−
−## Photosensors (Daylight)
−
−```datasheet
−label: Photosensor Control Method
−type: radio
−options:
− - "Closed-loop (measures total light at the task)"
− - "Open-loop (measures available daylight only)"
−default: "Closed-loop (measures total light at the task)"
−```
−
−A closed-loop photosensor measures the combined daylight and electric light at the controlled surface and adjusts the electric lighting to hold a target level; it is the common choice for an interior daylit zone because it directly regulates the delivered light. An open-loop photosensor measures incoming daylight only, away from the influence of the electric lighting it controls, and is suited to large toplit areas and skylight wells where a single sensor governs many luminaires. The method shall match the daylit zone geometry, and the sensor location shall be [[drawing: as indicated on the lighting control plan]].
−
−```datasheet
−label: Daylight Response
−type: radio
−options:
− - "Continuous dimming"
− - "Stepped switching"
−default: "Continuous dimming"
−```
−
−Continuous dimming smoothly reduces the electric lighting as daylight rises and is far less noticeable to occupants than stepped switching, which changes light in visible increments and can be distracting. Continuous dimming is the appropriate default and is required by most codes for the primary daylit zone; stepped control may be acceptable only in secondary daylit areas or where the code permits it.
−
−## Time Switches and Scheduling
−
−```datasheet
−label: Scheduling Control Type
−type: select
−options:
− - "Astronomical time switch (tracks sunrise/sunset)"
− - "7-day programmable time switch"
− - "Networked schedule (central controller)"
− - "Not used (occupancy-based shutoff only)"
−default: "Networked schedule (central controller)"
−```
−
−Schedule-based control turns lighting off during programmed unoccupied hours and is one of the accepted means of automatic shutoff. A networked schedule maintained at a central controller is the practical default for any building with a control network because it allows schedules and holiday exceptions to be managed in one place and adjusted without re-visiting each device. A standalone programmable time switch is appropriate for small projects without a network. Where schedule control is the means of shutoff, a manual local override of limited duration and limited area shall be provided as required by the energy code.
−
−## Manual Switches and Dimmers
−
−Each enclosed space shall have a readily accessible manual control that allows occupants to turn the lighting off and, where the space is dimmable, to reduce it, in addition to and independent of the automatic controls, as required by the energy code. Manual control gives occupants the ability to turn lighting off when the automatic controls would leave it on, which both saves energy and satisfies the manual-control mandate. Ordinary wall switches and dimmers furnished where no automatic control is associated with them are wiring devices specified under [[sync/wiring-devices]]; this standard governs manual controls that are part of, or interface with, the automatic control system.
−
−```datasheet
−label: Manual Dimming Control Type
−type: select
−options:
− - "Manual low-voltage dimmer (to driver dimming input)"
− - "Manual line-voltage (phase-cut) dimmer"
− - "Digital wall station (networked / DALI)"
− - "On/off switch only (non-dimming spaces)"
−default: "Digital wall station (networked / DALI)"
−```
−
−In a space with dimmable luminaires and a networked or digital control system, a digital wall station that commands the controller is preferred because it allows scenes, multi-zone control, and reprogramming without rewiring. A low-voltage manual dimmer that drives the luminaire's 0–10V input directly suits a simple standalone dimmable space. A line-voltage phase-cut dimmer is used only where the luminaire driver is controlled directly from the line-voltage wall control and shall be confirmed compatible with the driver. An on/off switch is appropriate only where the energy code permits non-dimming control.
−
−## Relay and Contactor Panels
−
−```datasheet
−label: Relay / Contactor Panel Use
−type: radio
−options:
− - "Not used (control at device / driver level)"
− - "Used for branch-circuit switching of zones"
−default: "Used for branch-circuit switching of zones"
−```
−
−A relay or contactor panel switches whole branch circuits on and off under the command of the control system and is the means of switching large zones, exterior and parking circuits, and non-dimmed loads. The panel shall be listed to UL 508, and its relays shall be rated for the inrush current of the LED driver loads they switch in accordance with NEMA 410, because LED drivers draw a high momentary inrush that welds relay contacts not rated for it. Relay panel locations and zone-to-circuit assignments shall be [[drawing: as indicated on the lighting control plan and panel schedules]].
−
−# Dimming and Control Interface
−
−The control interface is the electrical means by which a control device commands the luminaire's driver to a light level. It is the boundary between this standard and [[sync/lighting-fixtures]]: the luminaire's driver provides the dimming input, and the control system provides the signal to it. The interface selected here shall match the dimming input specified for the luminaire so the two are compatible, because a control system and a driver that speak different protocols cannot be made to dim together.
−
−## Control Interface Protocol
−
−```datasheet
−label: Lighting Control Interface
−type: select
−options:
− - "0-10V analog (ANSI C137.1)"
− - "DALI / DALI-2 (IEC 62386)"
− - "Phase-cut (forward/reverse)"
− - "Networked / proprietary digital with gateway"
− - "Integral wireless control"
−default: "0-10V analog (ANSI C137.1)"
−```
−
−The 0–10V analog interface, standardized by ANSI C137.1, is the default for commercial interior LED control: it is simple, low-cost, universally supported, and uses a low-voltage DC control pair separate from the line wiring, with the control device sinking current to set the level. Its limitations are that it is a one-way signal with no feedback, each zone needs its own control pair, and it does not address individual luminaires. DALI/DALI-2 (IEC 62386) should be specified where individual addressable control, software grouping, scene control, and two-way driver feedback and diagnostics are required, as in reconfigurable open offices and tunable spaces; DALI is bidirectional, polarity-insensitive, and supports up to 64 control devices on a bus, and DALI-2 certification confirms cross-manufacturer interoperability. Phase-cut control may be used where the luminaire is dimmed from an existing line-voltage wall dimmer, but it is more prone to flicker, audible buzz, and dimmer-driver incompatibility and is not preferred for new commercial work. The interface shall match the driver dimming input specified under [[sync/lighting-fixtures]].
−
−## Minimum Controlled Dimming Level
−
−```datasheet
−label: Minimum Controlled Dimming Level
−type: select
−unit: percent of full output
−options:
− - "10% (standard commercial)"
− - "5% (offices, conference, hospitality)"
− - "1% (theaters, lecture, premium hospitality)"
−default: "10% (standard commercial)"
−```
−
−The minimum controlled level is the lowest output the control system and driver together can reach smoothly without flicker or dropout. A 10 percent minimum is adequate for general commercial spaces. A deeper minimum of 5 percent or 1 percent should be specified for conference rooms, auditoria, and hospitality where low-light scenes are expected; the control device and the driver shall be confirmed compatible at the specified low end, because the achievable minimum is a property of the pair, not of either alone, and a control system that commands 1 percent against a driver that bottoms out at 10 percent will not deliver the scene.
−
−## Color-Tuning Control
−
−```datasheet
−label: Color-Tuning Control
−type: radio
−options:
− - "Not required (fixed CCT)"
− - "Tunable white (independent CCT and intensity control)"
−default: "Not required (fixed CCT)"
−```
−
−Where the luminaires are color-tunable, the control system shall provide the additional channels needed to command color temperature independently of intensity, which a single 0–10V pair cannot do and which is the principal reason DALI or a multi-channel networked system is selected for tunable spaces. Color-tuning control is required only where tunable-white or warm-dim luminaires are specified under [[sync/lighting-fixtures]], such as in healthcare, education, and circadian-lighting applications.
−
−# Networked and Luminaire-Level Lighting Control
−
−A networked lighting control (NLC) system connects the control devices, luminaires, and controllers on a digital network so that zones, schedules, sensor responses, and dimming levels are configured and reconfigured in software rather than by rewiring. Networked control is increasingly the practical means of meeting the layered control requirements of current energy codes, of accepting a demand-response signal, and of reporting energy use, and it is a prerequisite for the utility incentives available to NLC and LLLC systems.
−
−## Control System Architecture
−
−```datasheet
−label: Control System Architecture
−type: select
−options:
− - "Standalone / room-based (no network)"
− - "Networked wired (digital bus)"
− - "Networked wireless (mesh)"
− - "Luminaire-level lighting control (LLLC)"
−default: "Networked wired (digital bus)"
−```
−
−A standalone, room-based system in which each room's sensor, switch, and power pack operate independently is appropriate for small projects and tenant fit-outs where no central management is needed. A networked wired system connects devices on a digital bus and is robust and free of radio-frequency concerns but requires control wiring throughout. A networked wireless mesh reduces control wiring and eases reconfiguration but depends on radio coverage and shall use devices compliant with FCC Part 15. Luminaire-level lighting control places an occupancy sensor, a photosensor, and a controller in or on each luminaire so that every fixture is its own control zone; LLLC provides the finest-grained control and the greatest measured savings and is the basis of the DLC LLLC incentive, at a higher device cost. The architecture shall be coordinated with the project's control intent and incentive strategy.
−
−## Network Integration
−
−```datasheet
−label: Building Network Integration
−type: radio
−options:
− - "Standalone (no external integration)"
− - "Integrated with building automation / management system"
−default: "Standalone (no external integration)"
−```
−
−Where the lighting control system must report to or take commands from a building-wide control and monitoring system, integration shall be through a documented gateway and open protocol, and the points exchanged shall be coordinated with [[sync/building-automation-system]]. The lighting control system shall retain full local control of all life-safety and code-required functions independent of the building management network, so that a failure or outage of the building network does not disable required lighting control or emergency operation.
−
−## Low-Voltage Control Power
−
−```datasheet
−label: Control Circuit Class
−type: radio
−options:
− - "Class 2 (low-voltage, power-limited per NEC 725)"
− - "Class 1 (where required by device or distance)"
−default: "Class 2 (low-voltage, power-limited per NEC 725)"
−```
−
−Most lighting control wiring is Class 2 power-limited wiring under NFPA 70 Article 725, supplied by a listed power pack or controller, which simplifies installation and reduces shock and fire risk. Class 1 wiring shall be used only where a device's power demand or the circuit length requires it. The class of every control circuit shall be confirmed against Article 725 and the wiring methods kept consistent with that class throughout.
−
−# Emergency Lighting Control
−
−Lighting that serves the means of egress is frequently switched, dimmed, or scheduled along with the general lighting, but it shall never be left off when normal power fails. NFPA 70 Article 700 requires that any control on an emergency or egress luminaire be overridden so the luminaire goes to full output on loss of normal power, regardless of the position of any switch, dimmer, occupancy sensor, or schedule. This is accomplished with a device listed to UL 924.
−
−## Emergency Control Device
−
−```datasheet
−label: Emergency Lighting Control Device
−type: select
−options:
− - "None (egress lighting not switched/dimmed)"
− - "Automatic load control relay (UL 924)"
− - "Emergency control unit / shunt relay (UL 924)"
− - "UL 924-listed function within networked control system"
−default: "Automatic load control relay (UL 924)"
−```
−
−An automatic load control relay (ALCR) — a UL 924-listed device commonly called a shunt relay — monitors normal power and bypasses the local control to drive the controlled egress luminaire to full output when normal power is lost, locking out occupancy, dimming, and switching until normal power returns. An ALCR is the standard means of allowing an egress luminaire to be controlled like any other fixture during normal operation while guaranteeing it cannot be dark in an emergency. Where the egress lighting is not switched or dimmed, no emergency control device is needed; where the lighting control network itself is UL 924 listed for this function, that listed capability may serve in place of a discrete relay. The device shall be located and connected so it senses the normal power that serves the area it protects.
−
−## Transfer Timing
−
−The emergency control device shall force the controlled egress lighting to full output within the time NFPA 101 and the adopted code require following loss of normal power, and shall return control to the normal control system only after normal power is restored and stable. The device shall monitor the normal power source for the area it serves, not merely the presence of power at the device, so that a localized loss of the normal circuit is detected. The egress illumination levels, the emergency power source, and the duration are a design responsibility outside this standard and shall be coordinated with [[sync/emergency-and-standby-power]].
−
−## Self-Testing
−
−```datasheet
−label: Emergency Control Self-Test
−type: radio
−options:
− - "Manual test only"
− - "Self-testing / self-diagnostic"
−default: "Manual test only"
−```
−
−A self-testing emergency control device automatically exercises its transfer function on the periodic schedule the code requires and signals a fault, relieving the Owner of manual testing. Self-testing should be specified for installations with many distributed emergency control devices, because manual testing of dispersed relays is labor-intensive and frequently neglected.
−
−# Sequences of Operation
−
−The sequence of operation is the written description of how the lighting in each space responds to occupancy, vacancy, daylight, schedule, manual command, and loss of normal power. It is the heart of the controls specification: the devices are only the means, and a system installed exactly to the device schedule but programmed to the wrong sequence does not meet the design intent or the code. The sequences shall be documented for every space type and shall be the basis of the functional testing.
−
−## Documented Sequences Required
−
−A written sequence of operation shall be provided for each space type and control zone, and the system shall be programmed and commissioned to implement it. Each sequence shall state the automatic-on or manual-on behavior, the vacancy time delay, the daylight response and setpoints, the schedule and override behavior, the manual-control behavior, and the emergency override behavior. The space-by-space sequences and zone assignments shall be [[drawing: as indicated on the lighting control plan and sequence-of-operations schedule]], because which spaces are controlled how is project-specific and is established by the design.
−
−## Override and Manual Control Behavior
−
−Each automatic sequence shall define how a manual override interacts with it — how long an after-hours override holds lighting on, what area the override affects, and whether the automatic controls resume after the override expires. Overrides shall be limited in time and area as the energy code requires, so that a single occupant's override cannot defeat the automatic shutoff for an entire floor or for the remainder of the day.
−
−# Installation
−
−## Coordination with Ceiling and Luminaires
−
−The Contractor shall coordinate the location of ceiling-mounted sensors, photosensors, and wall stations with the reflected ceiling plan, the luminaire layout, and the furniture and partition plan before rough-in, so that sensors have the required coverage and are not blocked by ductwork, structure, partitions, or tall furniture. A sensor placed without regard to obstructions and air movement is the most common cause of a control system that fails its functional test. Devices shall be installed level, aligned, and at the locations shown.
−
−## Sensor Placement and Aiming
−
−Occupancy sensors shall be located and aimed so their coverage pattern includes the entire occupied area without extending into adjacent spaces or corridors where it would falsely hold lighting on, and ultrasonic sensors shall be kept away from supply-air diffusers whose airflow can false-trigger them. Photosensors shall be located so they sense the daylight or task surface they are intended to regulate and are shielded from direct view of the luminaires they control and from spill light from adjacent zones.
−
−## Low-Voltage Control Wiring
−
−Class 2 control wiring shall be installed in accordance with NFPA 70 Article 725, separated from line-voltage power wiring as required by the code and the device manufacturer, and supported independently of luminaires and ductwork. Control conductors shall be of the type and size the manufacturer requires for the run length so that voltage drop on the 0–10V or low-voltage signal does not corrupt the control level. Wiring methods and raceway shall comply with [[sync/conductors-and-cables]] and [[sync/raceways-and-conduit]]; line-voltage circuits switched by the controls shall be installed under those standards.
−
−## Grounding and Bonding
−
−Control panels, network controllers, and metal device enclosures shall be grounded and bonded in accordance with [[sync/grounding-and-bonding]]. Shielded control cabling, where used, shall be grounded at one end only as the manufacturer directs, because grounding a shield at both ends creates a ground loop that injects noise into the control signal.
−
−## Labeling and Identification
−
−Each control device, relay, controller, and zone shall be labeled to identify the circuits and zones it controls, and the labeling shall agree with the as-built control drawings and zone schedule. Labeling and identification shall be consistent with [[sync/equipment-labeling]]. Unlabeled controls are uncommissionable and unmaintainable, because no one can later determine which device governs which lighting.
−
−# Commissioning and Functional Testing
−
−The adopted energy code requires that the lighting controls be functionally tested — verified to be installed correctly, calibrated, and operating as the sequences of operation describe — before the building is accepted. ASHRAE 90.1 and the IECC call this functional testing; California Title 24 calls it acceptance testing and, unlike the model codes, requires it be performed by a certified acceptance-test technician working under a certified employer. The work is not complete until this testing is performed, documented, and accepted, because a control that is installed but mis-calibrated saves no energy and may not comply.
−
−## Functional Test Scope
−
−```datasheet
−label: Functional Test Documentation
−type: checkbox
−options:
− - "Occupancy/vacancy sensor operation and time delay verified per zone"
− - "Daylight photosensor setpoint and dimming response verified"
− - "Time-of-day schedule and after-hours override verified"
− - "Manual switching and dimming verified per zone"
− - "Demand-response reduction verified (where required)"
− - "Emergency override to full output on power loss verified (UL 924)"
− - "Calibration setpoints and programmed values recorded"
−default: "Occupancy/vacancy sensor operation and time delay verified per zone"
−```
−
−The Contractor shall demonstrate and document each required control function: that occupancy and vacancy sensors turn lighting on and off correctly and hold for the programmed delay; that daylight photosensors dim the electric lighting in response to daylight and hold the design level; that schedules turn lighting off and that overrides behave as specified; that manual controls operate each zone; that demand-response reduction occurs where required; and that the emergency control forces egress lighting to full output on a simulated loss of normal power. The tested setpoints and the result of each test shall be recorded.
−
−## Daylight Sensor Calibration
−
−Daylight-responsive photosensors shall be calibrated under representative daylight and electric-light conditions so that the controlled lighting holds the design level as daylight varies, and the calibration shall be verified by measurement, not assumed from the factory setting. Daylight controls that are installed but never calibrated are a frequent finding and deliver none of the savings the code anticipates, because an uncalibrated sensor either fails to dim or dims so aggressively that occupants override it.
−
−## Acceptance-Test Certification
−
−```datasheet
−label: Acceptance-Test Certification
−type: radio
−options:
− - "Functional test by qualified installer/commissioning agent"
− - "Certified acceptance-test technician (Title 24 jurisdictions)"
−default: "Functional test by qualified installer/commissioning agent"
−```
−
−In jurisdictions governed by California Title 24, the acceptance testing shall be performed by a certified Lighting Control Acceptance Test Technician under a certified employer, and the signed certificate shall be submitted as a condition of occupancy. In jurisdictions under ASHRAE 90.1 or the IECC, the functional testing may be performed by a qualified installer or the commissioning agent, and the documented results submitted to the authority having jurisdiction; the testing is no less required, only less prescriptive.
−
−## Owner Training
−
−The Contractor shall train the Owner's operating staff in the operation, adjustment, and basic troubleshooting of the control system, including how to change schedules, adjust setpoints, and add or move zones in a networked system. Training is essential because a control system that the Owner cannot adjust will be overridden, disabled, or left in a non-compliant state the first time the building's use changes.
−
−# Warranty
−
−```datasheet
−label: Control System Warranty Period
−type: select
−options:
− - "1 year from substantial completion"
− - "2 years from substantial completion"
− - "5 years from substantial completion"
−default: "2 years from substantial completion"
−```
−
−The control devices, controllers, and network shall be warranted against defects in materials and workmanship for the warranty period, and the warranty shall include the manufacturer's support for the programming and configuration software. A one-year warranty is the minimum; a longer warranty should be specified for networked systems, where the controller and software support are the components most likely to need vendor attention after installation.
−
−# Spare Parts
−
−```datasheet
−label: Spare Parts
−type: checkbox
−options:
− - "Spare occupancy/vacancy sensors (per type)"
− - "Spare photosensors (per type)"
− - "Spare power packs / relays (per type)"
− - "Spare wall stations / dimmers (per type)"
− - "Spare network controller / gateway"
−default: "Spare power packs / relays (per type)"
−```
−
−The Contractor shall furnish spare devices matching the installed types so the Owner can replace a failed device without re-engineering or a long lead time. Spare power packs and relays are the highest-value spare because they switch load and fail more often than sensors; a spare network controller or gateway should be furnished for a networked system whose product line may change, since a controller mismatch can require reprogramming the whole system.
+---
+title: Lighting Controls
+category: Electrical / Lighting
+toc_depth: 3
+description: >
+ When to use: The building lighting control system for commercial, institutional, and industrial projects — the sensors, switches, dimmers, time switches, relay and contactor panels, photosensors, and networked or luminaire-level control equipment that turn lighting on, off, and to intermediate levels in response to occupancy, daylight, schedule, and manual command. Covers the control devices, the dimming and control interface to the luminaire driver (0–10V, DALI/DALI-2, phase-cut), networked and luminaire-level control systems, the emergency lighting control interface required by UL 924, the low-voltage control wiring, the documented sequences of operation, and the commissioning and functional testing the energy code requires.
+ Not intended for: The luminaires themselves and their integral drivers and fixture-level dimming hardware (see [[sync/lighting-fixtures]]); exterior, site, and roadway lighting controls, photocontrols, and scheduling, which are covered with the exterior luminaires (see [[sync/exterior-lighting]]); the emergency and standby power sources, inverters, transfer equipment, and the egress illumination design itself (see [[sync/emergency-and-standby-power]]); integration of lighting into a building-wide control and monitoring network beyond the lighting control system's own gateway (see [[sync/building-automation-system]]); and wall switches and dimmers furnished as ordinary wiring devices where no automatic control is provided (see [[sync/wiring-devices]]).
+---
+
+# Scope {toc}
+
+## This specification covers the lighting control system — the devices and the logic that determine when and how much the building's lighting operates. {note}
+## It governs occupancy and vacancy sensors, photosensors for daylight response, time switches and astronomical schedules, manual switches and dimmers, relay and contactor panels, the dimming interface to the luminaire driver, networked and luminaire-level control systems, the emergency lighting control interface, the low-voltage control wiring, and the commissioning and functional testing that adopted energy codes require. {note}
+## The luminaires and their integral drivers are specified separately under [[sync/lighting-fixtures]]; this standard governs everything that tells those luminaires what to do. {note}
+
+## This standard is organized from the general to the specific: the administrative requirements first, then the individual control devices, then the dimming and control interface to the luminaire, then networked and luminaire-level systems, then the documented sequences of operation, then the installation and low-voltage wiring, and finally the commissioning and functional testing that closes out the work. {note}
+## The control intent — which spaces are controlled how, where sensors and switches are located, and how zones are bounded — is project-specific and is established on the contract drawings; this standard provides the framework, performance, and quality requirements that make those drawings buildable and compliant. {note}
+
+## Lighting controls are a code-compliance requirement under the adopted energy code — ANSI/ASHRAE/IES 90.1, the IECC, or in California Title 24, Part 6 — which mandates automatic shutoff, occupancy-based control, daylight-responsive control, and in many cases demand-responsive control for most interior spaces.
+
+## A lighting installation that meets every photometric and power-density target but lacks compliant controls shall not be accepted, because it does not pass plan review.
+
+## The control system shall be specified as outcomes the system is to achieve rather than as a particular manufacturer's product family. {note}
+
+## Where lighting on the egress path is switched, dimmed, or otherwise controlled, the control of that lighting shall be overridden to full output on loss of normal power through equipment listed to UL 924, in accordance with NFPA 70 (National Electrical Code) Article 700.
+
+## The emergency and standby power sources, the inverters and transfer equipment, and the egress illumination design itself are outside this standard and shall be coordinated under [[sync/emergency-and-standby-power]].
+
+# Referenced Standards {toc}
+
+## Equipment, materials, and installation shall comply with the latest adopted edition of the following standards and codes.
+
+| Standard | Title |
+|----------|-------|
+| UL 924 | Emergency Lighting and Power Equipment |
+| UL 916 | Energy Management Equipment |
+| UL 508 | Industrial Control Equipment |
+| UL 2043 | Fire Test for Heat and Visible Smoke Release for Discrete Products in Air-Handling Spaces |
+| NFPA 70 | National Electrical Code (Articles 700 — Emergency Systems; 725 — Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits; 410 — Luminaires) |
+| NFPA 101 | Life Safety Code |
+| ANSI/ASHRAE/IES 90.1 | Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
+| IECC | International Energy Conservation Code (Commercial Provisions, Section C405 — Electrical Power and Lighting Systems) |
+| California Title 24, Part 6 | California Building Energy Efficiency Standards |
+| ANSI C137.1 | Lighting Systems — 0–10V Dimming Interface for LED Drivers, Fluorescent Ballasts, and Controls |
+| ANSI C137.3 | Lighting Systems — Minimum Requirements for Installation of Energy Efficient Power Sources for Use with Light Emitting Diode Drivers |
+| ANSI C137.4 | Lighting Systems — Digital Interface with Auxiliary Power |
+| IEC 62386 | Digital Addressable Lighting Interface (DALI / DALI-2 / D4i) |
+| NEMA WD 7 | Occupancy Motion Sensors Standard |
+| NEMA 410 | Performance Testing for Lighting Controls and Switching Devices with Electronic Drivers and Discharge Ballasts (Inrush Current) |
+| FCC Part 15 | Radio Frequency Devices (for wireless control nodes) |
+
+## Where the contract documents, the adopted building or energy code, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+## DesignLights Consortium (DLC) Networked Lighting Control (NLC) and Luminaire Level Lighting Control (LLLC) qualified-products lists are utility-incentive programs, not consensus standards; where this standard references them it references the program's published technical requirements as a procurement screen, not as a code requirement. {note}
+
+## The Engineer shall confirm which energy code and edition the authority having jurisdiction has adopted, because the control requirements differ materially between ASHRAE 90.1, the IECC, and Title 24.
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### Contractor shall submit the following for the Engineer's review prior to procurement.
+
+- Product data for each control device type — occupancy/vacancy sensors, photosensors, time switches, manual switches and dimmers, relay/contactor panels, network controllers, gateways, and power packs — including coverage patterns, ratings, and the dimming interface supported
+- A control system narrative and point-to-point wiring diagrams showing every device, its zone assignment, its power source, and its connection to the luminaire driver
+- A written sequence of operations for each space type, describing the response to occupancy, vacancy, daylight, schedule, manual override, and loss of normal power
+- A zoning and device-location plan reconciled against the reflected ceiling plan and the lighting plan
+- For networked systems, the network architecture, addressing scheme, gateway and integration points, and the commissioning and programming plan
+- For emergency lighting control, UL 924 listing documentation for each automatic load control relay, emergency control unit, or shunt device, and a diagram showing how each controlled egress luminaire is forced to full output on loss of normal power
+- A commissioning and functional-test plan describing how each required control function will be demonstrated and documented
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Product data for each control device type"
+ - "Control system narrative and point-to-point wiring diagrams"
+ - "Written sequences of operation by space type"
+ - "Zoning and device-location plan"
+ - "Network architecture and commissioning/programming plan"
+ - "UL 924 documentation for emergency control devices"
+ - "Commissioning and functional-test plan"
+default: "Product data for each control device type"
+```
+
+### A bill of devices alone is not a sufficient submittal; the system shall be documented well enough to confirm it implements the required sequences of operation and satisfies the adopted energy code.
+
+## Closeout Submittals {toc}
+
+### Contractor shall provide the following at substantial completion.
+
+- Operation and maintenance data for each device and for the network controller, including the configuration and programming software where applicable
+- As-built control drawings, sequences of operation, and the final zone and device schedule reflecting installed conditions
+- The completed and signed functional-test (acceptance-test) documentation required by the adopted energy code, with the date, result, and tested setpoints for each control function
+- The final programmed settings — time-of-day schedules, occupancy time delays, daylight setpoints, dimming levels, and demand-response levels — recorded so the Owner can restore them after a controller replacement
+- Training records for the Owner's operating staff
+- For self-testing emergency control devices, documentation of the initial automatic test result
+
+```datasheet
+label: Closeout Submittals Required
+type: checkbox
+options:
+ - "Operation and maintenance data for each device and the network controller"
+ - "As-built control drawings, sequences, and final zone/device schedule"
+ - "Signed functional-test (acceptance-test) documentation"
+ - "Final programmed settings recorded for restoration"
+ - "Training records for the Owner's operating staff"
+ - "Initial automatic test result for self-testing emergency control devices"
+default: [Operation and maintenance data for each device and the network controller, As-built control drawings, sequences, and final zone/device schedule, Signed functional-test (acceptance-test) documentation, Final programmed settings recorded for restoration, Training records for the Owner's operating staff]
+```
+
+# Quality Assurance {toc}
+
+## Listing and Labeling {toc}
+
+### Control devices shall be listed and labeled by a Nationally Recognized Testing Laboratory for the application in which they are installed — energy management equipment to UL 916, industrial control equipment such as relay and contactor panels to UL 508, and emergency lighting control devices to UL 924.
+
+### An unlisted control device shall not be installed regardless of its apparent quality.
+
+### The listing establishes the device's voltage, current, and environmental ratings and its fitness for the circuit it controls. {note}
+
+## Plenum-Rated Devices {toc}
+
+```datasheet
+label: Plenum-Rated Devices Required
+type: radio
+options:
+ - "Not required (devices not in air-handling plenums)"
+ - "Required for devices installed in air-handling plenums (UL 2043)"
+default: "Required for devices installed in air-handling plenums (UL 2043)"
+```
+
+### Control devices and power packs installed above an accessible ceiling that serves as an air-handling plenum shall be listed to UL 2043 for fire and smoke release.
+
+### Devices in the plenum airstream contribute to smoke loading in a fire, an unlisted device is a code violation in that location, and most commercial ceilings return air through the plenum, so plenum-rated devices are the common case. {note}
+
+## Manufacturer System Compatibility {toc}
+
+### All components of a given control subsystem — sensors, controllers, dimmers, and the network — shall be from a compatible product family confirmed by the manufacturer to interoperate, or shall be certified to an open interoperability standard such as DALI-2 (IEC 62386).
+
+### Compatibility shall be confirmed at submittal, not discovered in the field.
+
+### Mixing devices that share only a nominal interface name but were never tested together is the most common cause of erratic dimming, failed daylight harvesting, and a system that cannot be commissioned. {note}
+
+## Qualified Products Screening {toc}
+
+```datasheet
+label: Qualified Products Listing Required
+type: radio
+options:
+ - "Not required"
+ - "DLC Networked Lighting Control (NLC) listed"
+ - "DLC Luminaire Level Lighting Control (LLLC) listed"
+default: "Not required"
+```
+
+### A DLC listing should be required where utility incentives are pursued.
+
+### The Engineer shall confirm the specific qualified-products list referenced by the relevant utility program.
+
+### Specifying a DLC NLC- or LLLC-listed system screens the controls against an independently verified set of capability and reporting requirements and is frequently a prerequisite for utility incentives, which can be substantial for networked controls. {note}
+
+# Energy Code Control Requirements {toc}
+
+## The adopted energy code dictates the minimum control functions for each space, and these requirements drive most of the device selections that follow. {note}
+
+## The Engineer shall confirm the adopted code and edition, because the three dominant codes differ in their thresholds and prescriptions, and the design shall meet whichever governs the project.
+
+## Applicable Energy Code {toc}
+
+```datasheet
+label: Governing Energy Code
+type: select
+options:
+ - "ANSI/ASHRAE/IES 90.1"
+ - "IECC (International Energy Conservation Code)"
+ - "California Title 24, Part 6"
+ - "Other state or local energy code"
+default: "IECC (International Energy Conservation Code)"
+```
+
+### Where the project is in California, Title 24 governs and shall be confirmed as the basis of design.
+
+### The IECC and ASHRAE 90.1 are the predominant commercial energy codes across most US jurisdictions, and a project may comply through either where both are adopted; California Title 24 is materially stricter — it mandates more space types for occupancy and daylight control, prescribes specific acceptance tests, and requires those tests be performed by a certified acceptance-test technician. {note}
+
+## Automatic Shutoff {toc}
+
+### Interior lighting in each space shall be provided with an automatic means to shut the lighting off when the space is unoccupied, accomplished by occupancy sensing, a time-of-day schedule, or a combination, in accordance with the adopted energy code.
+
+### A manual wall switch alone does not satisfy automatic shutoff.
+
+### Where a time switch is the means of shutoff, an override that returns lighting for a limited period shall be provided so occupants working after hours are not left in the dark.
+
+### The override shall affect only a limited area so that one occupant does not light an entire floor.
+
+## Occupancy and Vacancy Control {toc}
+
+### Spaces required by the energy code to have occupancy-based control shall reduce or extinguish lighting after the space is vacated within the time the code allows — generally not more than 20 minutes.
+
+### The controlled zone served by a single sensor shall not exceed the area the code permits, which the energy codes have progressively reduced.
+
+### Certain space types, notably enclosed offices, conference and meeting rooms, classrooms, restrooms, and storage rooms, are specifically required to have occupancy or vacancy control; the required space types shall be taken from the adopted code.
+
+## Daylight-Responsive Control {toc}
+
+### Lighting in daylit zones adjacent to windows (sidelit) and below skylights (toplit) shall be controlled by photosensors that reduce the electric lighting in response to available daylight, where the connected lighting load in the daylit zone exceeds the threshold the adopted code sets.
+
+### The control shall dim the daylit lighting continuously and shall be capable of reducing it to the low level the code requires.
+
+### Daylit zones that overlap shall be controlled together so that the controls do not fight one another.
+
+## Demand-Responsive Control {toc}
+
+```datasheet
+label: Automatic Demand-Responsive Control
+type: radio
+options:
+ - "Not required"
+ - "Required (large buildings per adopted energy code)"
+default: "Not required"
+```
+
+### Where the adopted energy code requires it — typically for buildings above a floor-area threshold — the lighting control system shall be capable of receiving a demand-response signal and automatically reducing the total building lighting power by the percentage the code prescribes without manual intervention.
+
+### Where required, the system's ability to accept the demand-response signal shall be confirmed and demonstrated.
+
+### Demand-responsive control is mandatory under Title 24 for qualifying buildings and is an option under ASHRAE 90.1 and the IECC. {note}
+
+# Control Devices {toc}
+
+## Occupancy and Vacancy Sensors {toc}
+
+### An occupancy sensor turns lighting on automatically when it detects presence and off after a vacancy delay (automatic-on). {note}
+### A vacancy sensor turns lighting on only by manual switch and off automatically after the space is vacated (manual-on, auto-off). {note}
+
+### Occupancy Control Mode {toc}
+
+```datasheet
+label: Occupancy Control Mode
+type: radio
+options:
+ - "Vacancy (manual-on, automatic-off)"
+ - "Occupancy (automatic-on, automatic-off)"
+ - "Partial-on (automatic to a reduced level, manual to full)"
+default: "Vacancy (manual-on, automatic-off)"
+```
+
+#### Vacancy (manual-on) control should be the default for private offices, conference rooms, classrooms, and similar enclosed spaces because it both saves the most energy and satisfies the manual-on requirement that several codes place on these spaces.
+
+#### Automatic-on control is appropriate for spaces where hands-free operation is important for safety or convenience, such as restrooms, corridors, and stairwells; partial-on control automatically brings lighting to a reduced level on entry and requires a manual action for full output. {note}
+
+### Sensor Detection Technology {toc}
+
+```datasheet
+label: Sensor Detection Technology
+type: select
+options:
+ - "Passive infrared (PIR)"
+ - "Ultrasonic"
+ - "Dual-technology (PIR + ultrasonic)"
+ - "Microphonic / acoustic-assisted"
+default: "Dual-technology (PIR + ultrasonic)"
+```
+
+#### Dual-technology sensors are the appropriate default for the majority of enclosed spaces.
+
+#### Single-technology sensors should be selected only where the space clearly favors one technology and cost is a concern.
+
+#### Passive infrared sensors detect the heat motion of an occupant and require an unobstructed line of sight; they are immune to false triggering from air movement but miss small motions and occupants behind partitions. Ultrasonic sensors detect motion by Doppler shift, fill a space around obstructions, and catch small motions such as typing, but can false-trigger on airflow from diffusers. Dual-technology sensors require both signals to turn lighting on and either to hold it on, which suppresses false-on and false-off. {note}
+
+### Occupancy Vacancy Time Delay {toc}
+
+```datasheet
+label: Occupancy Vacancy Time Delay
+type: select
+unit: minutes
+options:
+ - "5 minutes"
+ - "10 minutes"
+ - "15 minutes"
+ - "20 minutes (code maximum)"
+default: "15 minutes"
+```
+
+#### The time delay shall not exceed the maximum the adopted code permits.
+
+#### The time delay is how long the sensor holds lighting on after it last detects occupancy; too short a delay produces nuisance switching that annoys occupants and stresses the driver, too long wastes the energy the control is meant to save, and a delay of about 15 minutes balances comfort against savings for most office and classroom use. {note}
+
+### Sensor Mounting and Coverage {toc}
+
+```datasheet
+label: Sensor Mounting / Coverage Type
+type: select
+options:
+ - "Ceiling-mounted (360-degree)"
+ - "Wall-switch replacement (integral to switch)"
+ - "Wall/corner mounted (wide angle)"
+ - "High-bay / aisle (long-throw)"
+ - "Fixture-integral (luminaire-level)"
+default: "Ceiling-mounted (360-degree)"
+```
+
+#### The mounting type and coverage pattern shall match the geometry of the space so the entire occupied area is reliably detected without gaps or false triggers.
+
+#### Sensor type, location, and coverage shall be [[drawing: as indicated on the lighting control plan]].
+
+#### A wall-switch occupancy sensor is economical for small enclosed rooms; ceiling sensors cover open areas; long-throw sensors suit warehouse aisles and high-bay spaces; and fixture-integral sensors are part of a luminaire-level control system addressed below. {note}
+
+## Photosensors (Daylight) {toc}
+
+### Photosensor Control Method {toc}
+
+```datasheet
+label: Photosensor Control Method
+type: radio
+options:
+ - "Closed-loop (measures total light at the task)"
+ - "Open-loop (measures available daylight only)"
+default: "Closed-loop (measures total light at the task)"
+```
+
+#### The photosensor control method shall match the daylit zone geometry, and the sensor location shall be [[drawing: as indicated on the lighting control plan]].
+
+#### A closed-loop photosensor measures the combined daylight and electric light at the controlled surface and adjusts the electric lighting to hold a target level, and is the common choice for an interior daylit zone; an open-loop photosensor measures incoming daylight only, away from the influence of the electric lighting it controls, and is suited to large toplit areas and skylight wells where a single sensor governs many luminaires. {note}
+
+### Daylight Response {toc}
+
+```datasheet
+label: Daylight Response
+type: radio
+options:
+ - "Continuous dimming"
+ - "Stepped switching"
+default: "Continuous dimming"
+```
+
+#### Continuous dimming is the appropriate default and is required by most codes for the primary daylit zone; stepped control may be acceptable only in secondary daylit areas or where the code permits it.
+
+#### Continuous dimming smoothly reduces the electric lighting as daylight rises and is far less noticeable to occupants than stepped switching, which changes light in visible increments and can be distracting. {note}
+
+## Time Switches and Scheduling {toc}
+
+```datasheet
+label: Scheduling Control Type
+type: select
+options:
+ - "Astronomical time switch (tracks sunrise/sunset)"
+ - "7-day programmable time switch"
+ - "Networked schedule (central controller)"
+ - "Not used (occupancy-based shutoff only)"
+default: "Networked schedule (central controller)"
+```
+
+### Where schedule control is the means of shutoff, a manual local override of limited duration and limited area shall be provided as required by the energy code.
+
+### Schedule-based control turns lighting off during programmed unoccupied hours and is one of the accepted means of automatic shutoff; a networked schedule maintained at a central controller is the practical default for any building with a control network, while a standalone programmable time switch is appropriate for small projects without a network. {note}
+
+## Manual Switches and Dimmers {toc}
+
+### Each enclosed space shall have a readily accessible manual control that allows occupants to turn the lighting off and, where the space is dimmable, to reduce it, in addition to and independent of the automatic controls, as required by the energy code.
+
+### Ordinary wall switches and dimmers furnished where no automatic control is associated with them are wiring devices specified under [[sync/wiring-devices]]; this standard governs manual controls that are part of, or interface with, the automatic control system.
+
+### Manual control gives occupants the ability to turn lighting off when the automatic controls would leave it on, which both saves energy and satisfies the manual-control mandate. {note}
+
+### Manual Dimming Control Type {toc}
+
+```datasheet
+label: Manual Dimming Control Type
+type: select
+options:
+ - "Manual low-voltage dimmer (to driver dimming input)"
+ - "Manual line-voltage (phase-cut) dimmer"
+ - "Digital wall station (networked / DALI)"
+ - "On/off switch only (non-dimming spaces)"
+default: "Digital wall station (networked / DALI)"
+```
+
+#### A line-voltage phase-cut dimmer is used only where the luminaire driver is controlled directly from the line-voltage wall control and shall be confirmed compatible with the driver.
+
+#### An on/off switch is appropriate only where the energy code permits non-dimming control.
+
+#### In a space with dimmable luminaires and a networked or digital control system, a digital wall station that commands the controller is preferred because it allows scenes, multi-zone control, and reprogramming without rewiring; a low-voltage manual dimmer that drives the luminaire's 0–10V input directly suits a simple standalone dimmable space. {note}
+
+## Relay and Contactor Panels {toc}
+
+```datasheet
+label: Relay / Contactor Panel Use
+type: radio
+options:
+ - "Not used (control at device / driver level)"
+ - "Used for branch-circuit switching of zones"
+default: "Used for branch-circuit switching of zones"
+```
+
+### The relay or contactor panel shall be listed to UL 508.
+
+### The panel's relays shall be rated for the inrush current of the LED driver loads they switch in accordance with NEMA 410.
+
+### Relay panel locations and zone-to-circuit assignments shall be [[drawing: as indicated on the lighting control plan and panel schedules]].
+
+### A relay or contactor panel switches whole branch circuits on and off under the command of the control system and is the means of switching large zones, exterior and parking circuits, and non-dimmed loads; LED drivers draw a high momentary inrush that welds relay contacts not rated for it. {note}
+
+# Dimming and Control Interface {toc}
+
+## The control interface is the electrical means by which a control device commands the luminaire's driver to a light level. {note}
+## It is the boundary between this standard and [[sync/lighting-fixtures]]: the luminaire's driver provides the dimming input, and the control system provides the signal to it. {note}
+
+## The interface selected here shall match the dimming input specified for the luminaire so the two are compatible, because a control system and a driver that speak different protocols cannot be made to dim together.
+
+## Control Interface Protocol {toc}
+
+```datasheet
+label: Lighting Control Interface
+type: select
+options:
+ - "0-10V analog (ANSI C137.1)"
+ - "DALI / DALI-2 (IEC 62386)"
+ - "Phase-cut (forward/reverse)"
+ - "Networked / proprietary digital with gateway"
+ - "Integral wireless control"
+default: "0-10V analog (ANSI C137.1)"
+```
+
+### The 0–10V analog interface (ANSI C137.1) is the default for commercial interior LED control.
+
+### DALI/DALI-2 (IEC 62386) should be specified where individual addressable control, software grouping, scene control, and two-way driver feedback and diagnostics are required, as in reconfigurable open offices and tunable spaces.
+
+### Phase-cut control may be used where the luminaire is dimmed from an existing line-voltage wall dimmer, but it is more prone to flicker, audible buzz, and dimmer-driver incompatibility and is not preferred for new commercial work.
+
+### The interface shall match the driver dimming input specified under [[sync/lighting-fixtures]].
+
+### The 0–10V interface is simple, low-cost, and universally supported but is one-way with no feedback, each zone needs its own control pair, and it does not address individual luminaires; DALI is bidirectional, polarity-insensitive, and supports up to 64 control devices on a bus, and DALI-2 certification confirms cross-manufacturer interoperability. {note}
+
+## Minimum Controlled Dimming Level {toc}
+
+```datasheet
+label: Minimum Controlled Dimming Level
+type: select
+unit: percent of full output
+options:
+ - "10% (standard commercial)"
+ - "5% (offices, conference, hospitality)"
+ - "1% (theaters, lecture, premium hospitality)"
+default: "10% (standard commercial)"
+```
+
+### A deeper minimum of 5 percent or 1 percent should be specified for conference rooms, auditoria, and hospitality where low-light scenes are expected.
+
+### The control device and the driver shall be confirmed compatible at the specified low end.
+
+### The minimum controlled level is the lowest output the control system and driver together can reach smoothly without flicker or dropout; a 10 percent minimum is adequate for general commercial spaces, and the achievable minimum is a property of the pair, not of either alone, so a control system that commands 1 percent against a driver that bottoms out at 10 percent will not deliver the scene. {note}
+
+## Color-Tuning Control {toc}
+
+```datasheet
+label: Color-Tuning Control
+type: radio
+options:
+ - "Not required (fixed CCT)"
+ - "Tunable white (independent CCT and intensity control)"
+default: "Not required (fixed CCT)"
+```
+
+### Where the luminaires are color-tunable, the control system shall provide the additional channels needed to command color temperature independently of intensity.
+
+### Color-tuning control is required only where tunable-white or warm-dim luminaires are specified under [[sync/lighting-fixtures]], such as in healthcare, education, and circadian-lighting applications; a single 0–10V pair cannot command color temperature independently, which is the principal reason DALI or a multi-channel networked system is selected for tunable spaces. {note}
+
+# Networked and Luminaire-Level Lighting Control {toc}
+
+## A networked lighting control (NLC) system connects the control devices, luminaires, and controllers on a digital network so that zones, schedules, sensor responses, and dimming levels are configured and reconfigured in software rather than by rewiring. {note}
+
+## Networked control is increasingly the practical means of meeting the layered control requirements of current energy codes, of accepting a demand-response signal, and of reporting energy use, and it is a prerequisite for the utility incentives available to NLC and LLLC systems. {note}
+
+## Control System Architecture {toc}
+
+```datasheet
+label: Control System Architecture
+type: select
+options:
+ - "Standalone / room-based (no network)"
+ - "Networked wired (digital bus)"
+ - "Networked wireless (mesh)"
+ - "Luminaire-level lighting control (LLLC)"
+default: "Networked wired (digital bus)"
+```
+
+### A networked wireless mesh shall use devices compliant with FCC Part 15.
+
+### The architecture shall be coordinated with the project's control intent and incentive strategy.
+
+### A standalone, room-based system is appropriate for small projects and tenant fit-outs where no central management is needed; a networked wired system is robust and free of radio-frequency concerns but requires control wiring throughout; a networked wireless mesh reduces control wiring and eases reconfiguration but depends on radio coverage; and luminaire-level lighting control places an occupancy sensor, a photosensor, and a controller in or on each luminaire so that every fixture is its own control zone, providing the finest-grained control and the greatest measured savings at a higher device cost. {note}
+
+## Network Integration {toc}
+
+```datasheet
+label: Building Network Integration
+type: radio
+options:
+ - "Standalone (no external integration)"
+ - "Integrated with building automation / management system"
+default: "Standalone (no external integration)"
+```
+
+### Where the lighting control system must report to or take commands from a building-wide control and monitoring system, integration shall be through a documented gateway and open protocol, and the points exchanged shall be coordinated with [[sync/building-automation-system]].
+
+### The lighting control system shall retain full local control of all life-safety and code-required functions independent of the building management network, so that a failure or outage of the building network does not disable required lighting control or emergency operation.
+
+## Low-Voltage Control Power {toc}
+
+```datasheet
+label: Control Circuit Class
+type: radio
+options:
+ - "Class 2 (low-voltage, power-limited per NEC 725)"
+ - "Class 1 (where required by device or distance)"
+default: "Class 2 (low-voltage, power-limited per NEC 725)"
+```
+
+### Class 1 wiring shall be used only where a device's power demand or the circuit length requires it.
+
+### The class of every control circuit shall be confirmed against Article 725 and the wiring methods kept consistent with that class throughout.
+
+### Most lighting control wiring is Class 2 power-limited wiring under NFPA 70 Article 725, supplied by a listed power pack or controller, which simplifies installation and reduces shock and fire risk. {note}
+
+# Emergency Lighting Control {toc}
+
+## Lighting that serves the means of egress is frequently switched, dimmed, or scheduled along with the general lighting, but it shall never be left off when normal power fails.
+
+## NFPA 70 Article 700 requires that any control on an emergency or egress luminaire be overridden so the luminaire goes to full output on loss of normal power, regardless of the position of any switch, dimmer, occupancy sensor, or schedule, accomplished with a device listed to UL 924.
+
+## Emergency Control Device {toc}
+
+```datasheet
+label: Emergency Lighting Control Device
+type: select
+options:
+ - "None (egress lighting not switched/dimmed)"
+ - "Automatic load control relay (UL 924)"
+ - "Emergency control unit / shunt relay (UL 924)"
+ - "UL 924-listed function within networked control system"
+default: "Automatic load control relay (UL 924)"
+```
+
+### Where the egress lighting is not switched or dimmed, no emergency control device is needed; where the lighting control network itself is UL 924 listed for this function, that listed capability may serve in place of a discrete relay.
+
+### The device shall be located and connected so it senses the normal power that serves the area it protects.
+
+### An automatic load control relay (ALCR) — a UL 924-listed device commonly called a shunt relay — monitors normal power and bypasses the local control to drive the controlled egress luminaire to full output when normal power is lost, locking out occupancy, dimming, and switching until normal power returns, and is the standard means of allowing an egress luminaire to be controlled like any other fixture during normal operation while guaranteeing it cannot be dark in an emergency. {note}
+
+## Transfer Timing {toc}
+
+### The emergency control device shall force the controlled egress lighting to full output within the time NFPA 101 and the adopted code require following loss of normal power, and shall return control to the normal control system only after normal power is restored and stable.
+
+### The device shall monitor the normal power source for the area it serves, not merely the presence of power at the device, so that a localized loss of the normal circuit is detected.
+
+### The egress illumination levels, the emergency power source, and the duration are a design responsibility outside this standard and shall be coordinated with [[sync/emergency-and-standby-power]].
+
+## Self-Testing {toc}
+
+```datasheet
+label: Emergency Control Self-Test
+type: radio
+options:
+ - "Manual test only"
+ - "Self-testing / self-diagnostic"
+default: "Manual test only"
+```
+
+### Self-testing should be specified for installations with many distributed emergency control devices.
+
+### A self-testing emergency control device automatically exercises its transfer function on the periodic schedule the code requires and signals a fault, relieving the Owner of manual testing, which for dispersed relays is labor-intensive and frequently neglected. {note}
+
+# Sequences of Operation {toc}
+
+## The sequence of operation is the written description of how the lighting in each space responds to occupancy, vacancy, daylight, schedule, manual command, and loss of normal power. {note}
+
+## It is the heart of the controls specification: the devices are only the means, and a system installed exactly to the device schedule but programmed to the wrong sequence does not meet the design intent or the code. {note}
+
+## Documented Sequences Required {toc}
+
+### A written sequence of operation shall be provided for each space type and control zone, and the system shall be programmed and commissioned to implement it.
+
+### Each sequence shall state the automatic-on or manual-on behavior, the vacancy time delay, the daylight response and setpoints, the schedule and override behavior, the manual-control behavior, and the emergency override behavior.
+
+### The space-by-space sequences and zone assignments shall be [[drawing: as indicated on the lighting control plan and sequence-of-operations schedule]], because which spaces are controlled how is project-specific and is established by the design.
+
+## Override and Manual Control Behavior {toc}
+
+### Each automatic sequence shall define how a manual override interacts with it — how long an after-hours override holds lighting on, what area the override affects, and whether the automatic controls resume after the override expires.
+
+### Overrides shall be limited in time and area as the energy code requires, so that a single occupant's override cannot defeat the automatic shutoff for an entire floor or for the remainder of the day.
+
+# Installation {toc}
+
+## Coordination with Ceiling and Luminaires {toc}
+
+### The Contractor shall coordinate the location of ceiling-mounted sensors, photosensors, and wall stations with the reflected ceiling plan, the luminaire layout, and the furniture and partition plan before rough-in, so that sensors have the required coverage and are not blocked by ductwork, structure, partitions, or tall furniture.
+
+### Devices shall be installed level, aligned, and at the locations shown.
+
+### A sensor placed without regard to obstructions and air movement is the most common cause of a control system that fails its functional test. {note}
+
+## Sensor Placement and Aiming {toc}
+
+### Occupancy sensors shall be located and aimed so their coverage pattern includes the entire occupied area without extending into adjacent spaces or corridors where it would falsely hold lighting on.
+
+### Ultrasonic sensors shall be kept away from supply-air diffusers whose airflow can false-trigger them.
+
+### Photosensors shall be located so they sense the daylight or task surface they are intended to regulate and are shielded from direct view of the luminaires they control and from spill light from adjacent zones.
+
+## Low-Voltage Control Wiring {toc}
+
+### Class 2 control wiring shall be installed in accordance with NFPA 70 Article 725, separated from line-voltage power wiring as required by the code and the device manufacturer, and supported independently of luminaires and ductwork.
+
+### Control conductors shall be of the type and size the manufacturer requires for the run length so that voltage drop on the 0–10V or low-voltage signal does not corrupt the control level.
+
+### Wiring methods and raceway shall comply with [[sync/conductors-and-cables]] and [[sync/raceways-and-conduit]]; line-voltage circuits switched by the controls shall be installed under those standards.
+
+## Grounding and Bonding {toc}
+
+### Control panels, network controllers, and metal device enclosures shall be grounded and bonded in accordance with [[sync/grounding-and-bonding]].
+
+### Shielded control cabling, where used, shall be grounded at one end only as the manufacturer directs, because grounding a shield at both ends creates a ground loop that injects noise into the control signal.
+
+## Labeling and Identification {toc}
+
+### Each control device, relay, controller, and zone shall be labeled to identify the circuits and zones it controls, and the labeling shall agree with the as-built control drawings and zone schedule.
+
+### Labeling and identification shall be consistent with [[sync/equipment-labeling]].
+
+### Unlabeled controls are uncommissionable and unmaintainable, because no one can later determine which device governs which lighting. {note}
+
+# Commissioning and Functional Testing {toc}
+
+## The adopted energy code requires that the lighting controls be functionally tested — verified to be installed correctly, calibrated, and operating as the sequences of operation describe — before the building is accepted. {note}
+
+## The work is not complete until this testing is performed, documented, and accepted, because a control that is installed but mis-calibrated saves no energy and may not comply.
+
+## ASHRAE 90.1 and the IECC call this functional testing; California Title 24 calls it acceptance testing and, unlike the model codes, requires it be performed by a certified acceptance-test technician working under a certified employer. {note}
+
+## Functional Test Scope {toc}
+
+```datasheet
+label: Functional Test Documentation
+type: checkbox
+options:
+ - "Occupancy/vacancy sensor operation and time delay verified per zone"
+ - "Daylight photosensor setpoint and dimming response verified"
+ - "Time-of-day schedule and after-hours override verified"
+ - "Manual switching and dimming verified per zone"
+ - "Demand-response reduction verified (where required)"
+ - "Emergency override to full output on power loss verified (UL 924)"
+ - "Calibration setpoints and programmed values recorded"
+default: "Occupancy/vacancy sensor operation and time delay verified per zone"
+```
+
+### The Contractor shall demonstrate and document each required control function: that occupancy and vacancy sensors turn lighting on and off correctly and hold for the programmed delay; that daylight photosensors dim the electric lighting in response to daylight and hold the design level; that schedules turn lighting off and that overrides behave as specified; that manual controls operate each zone; that demand-response reduction occurs where required; and that the emergency control forces egress lighting to full output on a simulated loss of normal power.
+
+### The tested setpoints and the result of each test shall be recorded.
+
+## Daylight Sensor Calibration {toc}
+
+### Daylight-responsive photosensors shall be calibrated under representative daylight and electric-light conditions so that the controlled lighting holds the design level as daylight varies.
+
+### The calibration shall be verified by measurement, not assumed from the factory setting.
+
+### Daylight controls that are installed but never calibrated are a frequent finding and deliver none of the savings the code anticipates, because an uncalibrated sensor either fails to dim or dims so aggressively that occupants override it. {note}
+
+## Acceptance-Test Certification {toc}
+
+```datasheet
+label: Acceptance-Test Certification
+type: radio
+options:
+ - "Functional test by qualified installer/commissioning agent"
+ - "Certified acceptance-test technician (Title 24 jurisdictions)"
+default: "Functional test by qualified installer/commissioning agent"
+```
+
+### In jurisdictions governed by California Title 24, the acceptance testing shall be performed by a certified Lighting Control Acceptance Test Technician under a certified employer, and the signed certificate shall be submitted as a condition of occupancy.
+
+### In jurisdictions under ASHRAE 90.1 or the IECC, the functional testing may be performed by a qualified installer or the commissioning agent, and the documented results submitted to the authority having jurisdiction; the testing is no less required, only less prescriptive.
+
+## Owner Training {toc}
+
+### The Contractor shall train the Owner's operating staff in the operation, adjustment, and basic troubleshooting of the control system, including how to change schedules, adjust setpoints, and add or move zones in a networked system.
+
+### Training is essential because a control system that the Owner cannot adjust will be overridden, disabled, or left in a non-compliant state the first time the building's use changes. {note}
+
+# Warranty {toc}
+
+```datasheet
+label: Control System Warranty Period
+type: select
+options:
+ - "1 year from substantial completion"
+ - "2 years from substantial completion"
+ - "5 years from substantial completion"
+default: "2 years from substantial completion"
+```
+
+## The control devices, controllers, and network shall be warranted against defects in materials and workmanship for the warranty period, and the warranty shall include the manufacturer's support for the programming and configuration software.
+
+## A one-year warranty is the minimum; a longer warranty should be specified for networked systems, where the controller and software support are the components most likely to need vendor attention after installation.
+
+# Spare Parts {toc}
+
+```datasheet
+label: Spare Parts
+type: checkbox
+options:
+ - "Spare occupancy/vacancy sensors (per type)"
+ - "Spare photosensors (per type)"
+ - "Spare power packs / relays (per type)"
+ - "Spare wall stations / dimmers (per type)"
+ - "Spare network controller / gateway"
+default: "Spare power packs / relays (per type)"
+```
+
+## The Contractor shall furnish spare devices matching the installed types so the Owner can replace a failed device without re-engineering or a long lead time.
+
+## Spare power packs and relays are the highest-value spare because they switch load and fail more often than sensors; a spare network controller or gateway should be furnished for a networked system whose product line may change, since a controller mismatch can require reprogramming the whole system. {note}