SynC · Topic
These are the standards in the SynC Standards library that cover Low Voltage. Each one is a complete, plain-language specification: the scope it applies to, the requirements that govern it, and a structured equipment datasheet listing the values a project has to decide — ratings, materials, setpoints, and the standards each is verified against. All of it is free to read without an account and published under CC BY-SA 4.0.
A standard usually carries several topics, so most of the entries below also appear under neighbouring subjects. The topics each one carries are listed on its own page.
Electronic access control systems for managing pedestrian entry into commercial, institutional, and industrial buildings. Covers system architecture (standalone, networked, and cloud-managed), door controllers and panels, credential readers and credentials, electrified door hardware coordination, request-to-exit devices, door position switches, low-voltage power supplies with battery backup, controller and reader cabling, head-end software, user management and audit, fire alarm release interface, cybersecurity, and acceptance testing for swinging pedestrian doors.
Automatic transfer switches rated 1000 V and below, listed to UL 1008, that move a load between a normal source and an alternate source without operator action. Covers the switching mechanism, transition type, bypass-isolation construction, neutral treatment, the controller and its sensing, time delays, exerciser, load management and communications provisions, ratings including withstand and closing and short-time ratings, service-entrance construction, enclosures, identification, factory and field testing, installation, warranty, and spare parts, for switches serving emergency, legally required standby, optional standby, critical operations, and health care essential electrical system loads.
Building wire and cable for power, lighting, branch circuit, and feeder applications rated 600V and below in commercial, institutional, and industrial buildings. Covers single conductors installed in raceways and cable tray, Type MC metal-clad cable, and Type AC armored cable; conductor materials (copper and aluminum); insulation types (THHN/THWN-2, XHHW-2, RHW-2, USE-2); ampacity selection and derating; voltage drop; color coding and conductor identification; splicing, connectors, and terminations; pulling and installation; insulation resistance testing; and field acceptance.
Identification labels, nameplates, warning signs, panel directories, and color-coding for electrical distribution equipment and wiring rated 600V and below and for medium-voltage equipment served by the same project — switchgear, switchboards, panelboards, transformers, motor control centers, disconnects, automatic transfer switches, junction boxes, raceways, and conductors. Covers arc-flash warning labels driven by the arc-flash study, voltage-class and system color coding (normal, emergency, critical, standby, fire alarm, security), panelboard circuit directories, disconnecting-means identification, available fault current marking, and conductor and conduit identification.
Grounding and bonding of low-voltage (1000V and below) electrical systems for commercial, institutional, and industrial buildings. Covers the grounding electrode system, grounding electrode conductors, equipment grounding conductors, bonding of metallic systems, separately derived systems, ground bus and ground bars, connections and terminations, and field testing of installed grounding systems.
Separately procured pulse width modulated variable frequency drives rated 600 V and below, controlling three-phase AC induction motors on HVAC air and hydronic equipment — supply, return, and exhaust fans, chilled water, condenser water, and hot water pumps, and cooling tower fans. Covers drive ratings, enclosure and cooling selection, harmonic performance, bypass and disconnecting means, motor and cable compatibility, protective functions, building automation integration, testing, and installation for drives in mechanical rooms, electrical rooms, penthouses, and outdoor locations.
Factory-fabricated industrial control panels and enclosures that house instrumentation and controls (I&C) equipment for industrial, process, and water/wastewater (WTP/WWTP) facilities. Covers UL 508A listed control panels and enclosures housing programmable logic controllers, remote I/O, control relays, power supplies, network switches, and operator interface devices, rated 1000V and below. Addresses enclosure type rating selection (UL/NEMA Type 1, 3R, 4, 4X, 12), short-circuit current rating (SCCR) determination per UL 508A Supplement SB and NEC Article 409, enclosure sizing and component layout, internal power distribution and control power transformers, power-versus-signal wiring segregation, wire and terminal-block identification, thermal management, grounding and bonding, nameplates, and arc-flash labeling.
never for new adoptions — this standard has been merged into Panelboards, which carries its full content under the simple name.
Dead-front, free-standing low voltage distribution switchboards rated 600V and below, built to UL 891 and NEMA PB 2, with group-mounted molded-case or insulated-case circuit breakers (fixed-mounted or individually drawout). Covers service entrance and downstream distribution boards for commercial, institutional, and industrial facilities.
Metal-enclosed, low voltage power circuit breaker switchgear rated 600V and below for commercial, institutional, and industrial facilities. Covers indoor and outdoor configurations with drawout power circuit breakers.
Factory-assembled, floor-standing low-voltage motor control centers rated 600 V and below, listed to UL 845 and built to NEMA ICS 18, in which combination motor starter units, reduced-voltage starter units, variable frequency drive units, feeder units, control power units, and metering units plug onto a common vertical bus fed from a common horizontal bus. Covers the assembly ratings, the enclosure and structure, the bus, the wiring class and type, arc-flash mitigation, the unit construction and the devices inside each unit, communications, identification, factory and field testing, installation, warranty, and spares, for indoor and outdoor installations.
A time-current coordination study for low- and medium-voltage power distribution systems rated 38 kV and below, where multiple overcurrent protective devices are installed in series and selective operation is required. Covers the analysis, settings recommendations, and deliverables that demonstrate the closest upstream protective device to a fault opens first, leaving the rest of the system energized. Includes coordination of relays, low-voltage power circuit breakers, molded-case and insulated-case breakers, fuses, and motor starter overload elements; coordination with transformer through-fault damage curves, conductor damage curves, and motor starting and inrush envelopes; and the dedicated selective-coordination requirements of NEC 700.27 and 701.27 for emergency and legally required standby systems.
Conduit, tubing, and raceway systems that enclose and protect electrical power, lighting, and signaling conductors in commercial, institutional, and industrial buildings — including rigid metal conduit, intermediate metal conduit, electrical metallic tubing, flexible conduits, rigid PVC conduit, surface raceways, metal and nonmetallic wireways, and conduit fittings, boxes, and supports. Covers indoor and outdoor, exposed and concealed, wet and dry, and direct-burial raceway routing for branch circuits and feeders rated 1000V and below.
Calculation of available three-phase and line-to-ground short-circuit currents at every bus, transformer secondary, switchboard, panelboard, motor control center, and significant motor connection in a low- or medium-voltage power distribution system. The study output is used to specify equipment interrupting ratings, withstand ratings, and bus bracing, and to verify that installed and proposed equipment complies with NFPA 70 Article 110.9 and 110.10.