Engine Generators
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 6
to Rev 7
in Engine Generators.
---
title: Engine Generators
…90 unchanged lines
- "Controller submittal and annunciator point list"
- "Factory test plan and certificates"
−default: "Product data for generator and accessories"
+default:
+ - "Product data for generator and accessories"
+ - "Dimensioned shop drawings"
+ - "Single-line diagram and control interfaces"
+ - "Alternator reactance and starting kVA analysis"
+ - "Emissions compliance documentation"
+ - "Sound data at 7 m and at property line"
+ - "Fuel consumption and runtime calculation"
+ - "Cooling performance at design ambient"
+ - "Seismic certification (AC156)"
+ - "Controller submittal and annunciator point list"
+ - "Factory test plan and certificates"
```
…24 unchanged lines
- "Spare parts inventory list with part numbers"
- "Owner training sign-off sheet"
−default: [Operation and maintenance manuals (indexed), As-built drawings (conduit, fuel, exhaust routing), Signed NFPA 110 acceptance test record, Warranty documentation with commencement date]
+default:
+ - "Operation and maintenance manuals (indexed)"
+ - "As-built drawings (conduit, fuel, exhaust routing)"
+ - "Signed NFPA 110 acceptance test record"
+ - "Factory and field test reports with infrared scan"
+ - "Warranty documentation with commencement date"
+ - "Spare parts inventory list with part numbers"
+ - "Owner training sign-off sheet"
```
…42 unchanged lines
## Where site conditions exceed the standard rating basis, the set shall be derated per ISO 8528 and the alternator and engine selected accordingly.
−## The rating shall be confirmed against the site's design ambient. {note}
+## The rating shall be confirmed against the site's design ambient.
−### Standard rating conditions per ISO 8528 are 25 deg C ambient, 100 m altitude, 30 percent relative humidity, and 100 kPa barometric pressure; very few real sites match this basis exactly. {note}
+### Standard rating conditions per ISO 8528 are 25°C ambient, 100 m altitude, 30 percent relative humidity, and 100 kPa barometric pressure; very few real sites match this basis exactly. {note}
## Ambient Temperature {toc}
+### The design maximum ambient temperature at the installation shall be as indicated in the datasheet.
+
```datasheet
label: Design Ambient Temperature (Maximum)
−type: select
−unit: deg C
+type: range
+unit: '°C'
options:
− - "40 deg C (standard outdoor enclosure rating)"
− - "45 deg C (warm climate)"
− - "50 deg C (hot climate or rooftop)"
− - "55 deg C (extreme heat)"
−default: "40 deg C (standard outdoor enclosure rating)"
+ min: 40
+ max: 55
+ setpoints: [40, 45, 50, 55]
+default: 40
```
+### 40°C is the standard outdoor enclosure rating; the higher selections apply where the site design ambient exceeds it. {note}
+
### The cooling system shall be selected so that the engine coolant and after-cooler air temperatures remain within the engine manufacturer's limits at the design ambient with the set carrying its rated load.
…4 unchanged lines
## Altitude {toc}
+### The installation altitude shall be as indicated in the datasheet.
+
```datasheet
label: Installation Altitude
…9 unchanged lines
### The published kW rating shall be the derated output at the design altitude and ambient, not the standard-condition rating.
−### Naturally aspirated diesel engines lose roughly 3 percent of power per 300 m above 150 m, and additional derating applies above the engine manufacturer's threshold ambient; turbocharged engines hold output longer but eventually derate as well. {note}
+### Naturally aspirated diesel engines lose roughly 3 percent of power per 1,000 ft (300 m) above 500 ft (150 m), and additional derating applies above the engine manufacturer's threshold ambient; turbocharged engines hold output longer but eventually derate as well. {note}
## Cold Weather Service {toc}
+### The design minimum temperature at the installation shall be as indicated in the datasheet.
+
```datasheet
label: Design Minimum Temperature
type: select
−unit: deg C
+unit: '°C'
options:
− - "Above 0 deg C (warm climate)"
− - "0 to -10 deg C"
− - "-10 to -25 deg C"
− - "Below -25 deg C (arctic)"
−default: "-10 to -25 deg C"
+ - "Above 0°C"
+ - "0 to −10°C"
+ - "−10 to −25°C"
+ - "Below −25°C"
```
−### Where the design minimum temperature is at or below 0 deg C, cold weather start aids shall be provided as specified in the Engine and Batteries sections.
+### The design minimum temperature is a site climate value; the Engineer takes it from the project's design weather data and it drives the entire cold-start package. {note}
+### Where the design minimum temperature is at or below 0°C, cold weather start aids shall be provided as specified in the Engine and Batteries sections.
+
### NFPA 110 requires Level 1 systems to be capable of starting within 10 seconds of receiving a start signal; meeting this in cold weather requires a properly sized jacket water heater, battery heater pad, and (for very cold climates) lube oil heating. {note}
…10 unchanged lines
## Continuous Output Rating (kW) {toc}
+### The generator set continuous output rating at the project's site conditions and duty class shall be as indicated in the datasheet.
+
```datasheet
label: Generator Continuous Output (Site-Rated kW)
type: range
unit: kW
−drawing_ref: true
+drawing_ref: "generator schedule"
options:
min: 30
max: 2000
setpoints: [30, 60, 100, 150, 200, 300, 400, 500, 600, 750, 1000, 1250, 1500, 1750, 2000]
−default: 500
+default: deferred
```
−### The generator set continuous output rating at the project's site conditions and duty class shall be [[drawing: as indicated on the one-line diagram and the generator schedule]].
+### The Engineer shall provide both the standard-condition rating and the site-rated kW on the generator schedule.
−### The Engineer shall provide both the standard-condition rating and the site-rated kW on the schedule.
−
### The site-rated kW is the value that matters for connected-load sizing; it is the kW the set will actually deliver after derating for altitude, ambient, and any fuel selection (for example, the natural-gas rating of a dual-fuel engine is generally lower than its diesel rating). {note}
## Duty Class {toc}
+### The generator duty class shall be as indicated in the datasheet.
+
```datasheet
label: Generator Duty Class (per ISO 8528)
…13 unchanged lines
## Output Voltage and Configuration {toc}
+### The alternator output voltage and configuration shall be as indicated in the datasheet.
+
```datasheet
label: Output Voltage and Configuration
type: select
+drawing_ref: "one-line diagram"
options:
− - "208Y/120V, 3-phase, 4-wire"
− - "240/120V, 1-phase, 3-wire"
− - "240 delta / 120V, 3-phase, 4-wire (high-leg)"
− - "480Y/277V, 3-phase, 4-wire"
− - "600Y/347V, 3-phase, 4-wire"
−default: "480Y/277V, 3-phase, 4-wire"
+ - "208Y/120V, 3Φ 4-wire"
+ - "240/120V, 1Φ 3-wire"
+ - "240V delta / 120V, 3Φ 4-wire (high-leg)"
+ - "480Y/277V, 3Φ 4-wire"
+ - "600Y/347V, 3Φ 4-wire"
+default: deferred
```
+### The output frequency shall be as indicated in the datasheet.
+
```datasheet
label: Output Frequency
…6 unchanged lines
```
+### 60 Hz is the North American norm and is the datasheet default; a 50 Hz set is a distinct engine-alternator selection at a different rated speed, available for systems that operate at that frequency. {note}
+
### The selected voltage shall match the transfer switch and downstream distribution.
…4 unchanged lines
### NFPA 110 classifies emergency and standby power systems by Level, Type, and Class. {note}
+### The project's NFPA 110 Level, Type, and Class shall be as indicated in the datasheet.
+
```datasheet
label: NFPA 110 Level
…26 unchanged lines
- "Class 48 (48 hours)"
- "Class 96 (96 hours)"
−default: "Class 8 (8 hours)"
```
…16 unchanged lines
## Fuel {toc}
+### The engine fuel shall be as indicated in the datasheet.
+
```datasheet
label: Engine Fuel
…5 unchanged lines
- "Bi-fuel (diesel primary, natural gas supplement)"
- "Dual-fuel (natural gas or diesel, selectable)"
−default: "Diesel (No. 2 ULSD)"
```
### The Engineer shall confirm the AHJ's position before selecting natural gas for a Level 1 system.
−### Diesel No. 2 ultra-low sulfur (ULSD) is the default for sets serving NFPA 110 Level 1 systems because the on-site fuel inventory provides predictable runtime independent of the gas utility; natural gas eliminates on-site fuel storage but ties the set's availability to the gas utility, which is not always acceptable for life-safety loads in seismic or high-wind regions. {note}
+### Fuel selection is a project decision with no universally correct answer, which is why no fuel is preselected here. Diesel No. 2 ultra-low sulfur (ULSD) is the usual choice for sets serving NFPA 110 Level 1 systems because the on-site fuel inventory provides predictable runtime independent of the gas utility; natural gas eliminates on-site fuel storage but ties the set's availability to the gas utility, which is not always acceptable for life-safety loads in seismic or high-wind regions. {note}
### Combustion Air {toc}
…9 unchanged lines
## Emissions {toc}
+### The emissions compliance basis for the engine furnished shall be as indicated in the datasheet.
+
```datasheet
label: Diesel Engine EPA Tier
type: select
options:
− - "Tier 2 (legacy installations only)"
+ - "Tier 2 (existing legacy installation)"
- "Tier 3"
- "Tier 4 Interim"
…6 unchanged lines
type: radio
options:
+ - "Not applicable — compression-ignition (diesel) engine"
- "40 CFR Part 60 Subpart JJJJ (emergency rating)"
- "40 CFR Part 60 Subpart JJJJ (non-emergency rating)"
− - "Not applicable (diesel engine)"
−default: "Not applicable (diesel engine)"
```
…16 unchanged lines
## Start Aids {toc}
+### Each start aid below is fully determined by the NFPA 110 Type and the design minimum temperature already selected, so each is stated as a requirement rather than offered as a separate project selection. {note}
+
### Jacket Water Heater {toc}
−```datasheet
−label: Jacket Water Heater
−type: radio
−options:
− - "Required (NFPA 110 Type 10 or colder than 0 deg C)"
− - "Not required (warm climate, slower Type)"
−default: "Required (NFPA 110 Type 10 or colder than 0 deg C)"
−```
+#### A thermostatically controlled jacket water heater shall be provided on every NFPA 110 Type 10 system and wherever the design minimum temperature is at or below 0°C.
−#### A thermostatically controlled jacket water heater shall be provided to maintain engine coolant temperature at a value that allows reliable starting within the NFPA 110 Type time.
+#### The heater shall maintain engine coolant temperature at a value that allows reliable starting within the NFPA 110 Type time.
#### Heater wattage shall be sized for the engine displacement and the design minimum ambient.
…3 unchanged lines
### Battery Heater Pad {toc}
−```datasheet
−label: Battery Heater Pad
−type: radio
−options:
− - "Required (design minimum below 0 deg C)"
− - "Not required (warm climate)"
−default: "Required (design minimum below 0 deg C)"
−```
+#### Where the design minimum temperature is below 0°C, a thermostatically controlled battery heater pad shall be provided so that cranking capacity is preserved.
−#### Where the design minimum temperature is below 0 deg C, a thermostatically controlled battery heater pad shall be provided so that cranking capacity is preserved.
+#### Lead-acid battery cranking capacity drops sharply below 0°C, and an unheated battery in a cold enclosure may not crank a cold engine within 10 seconds. {note}
−#### Lead-acid battery cranking capacity drops sharply below 0 deg C, and an unheated battery in a cold enclosure may not crank a cold engine within 10 seconds. {note}
−
### Lube Oil Heater {toc}
−```datasheet
−label: Lube Oil Heater
−type: radio
−options:
− - "Required (design minimum below -15 deg C)"
− - "Not required"
−default: "Not required"
−```
+#### Where the design minimum temperature is below −15°C, or where the engine manufacturer requires it, a lube oil heater shall be provided.
−#### In design minimum conditions below -15 deg C, or where the engine manufacturer requires it, a lube oil heater shall be provided.
−
#### Cold lube oil increases cranking torque and lengthens start time; the heater maintains the oil at a temperature that allows the engine to crank and accept load within the required time. {note}
…8 unchanged lines
## Excitation {toc}
+### The alternator excitation type shall be as indicated in the datasheet.
+
```datasheet
label: Excitation Type
…9 unchanged lines
## Insulation Class and Temperature Rise {toc}
+### The alternator insulation class and temperature rise shall be as indicated in the datasheet.
+
```datasheet
−label: Alternator Insulation Class
+label: Alternator Insulation Class and Rise
type: radio
options:
- "Class H insulation, Class H temperature rise"
− - "Class H insulation, Class F temperature rise (recommended)"
+ - "Class H insulation, Class F temperature rise"
- "Class F insulation, Class B temperature rise"
−default: "Class H insulation, Class F temperature rise (recommended)"
+default: "Class H insulation, Class F temperature rise"
```
+### Alternator insulation classes here are the NEMA MG 1 rotating-machine letter classes, which remain the correct US designation for generator windings. {note}
+
### Specifying Class H insulation with a Class F temperature rise is the industry recommended practice because the insulation life is materially extended by operating at a lower temperature than its limit. {note}
…4 unchanged lines
### The regulator shall include a volts-per-hertz limiter to protect the alternator and connected loads on underspeed, an overvoltage limiter, and a separately adjustable underfrequency knee.
−## Performance {toc}
+## Where a specific alternator subtransient reactance is required to limit motor-starting voltage dip, it shall be as indicated in the datasheet.
```datasheet
label: Alternator Reactance (Subtransient, Xd")
−type: select
+type: radio
options:
− - "Standard (per manufacturer)"
− - "Low reactance (for stiff system / motor starting)"
−default: "Standard (per manufacturer)"
+ - "Standard reactance alternator"
+ - "Low reactance alternator (for stiff system / motor starting)"
+default: manufacturer
```
+## Where no reactance requirement is indicated, the manufacturer's standard alternator for the rating shall apply, and the manufacturer shall report the subtransient reactance and decrement curve in the action submittals.
+
+## The maximum instantaneous voltage dip on step load shall be as indicated in the datasheet.
+
```datasheet
label: Maximum Instantaneous Voltage Dip on Step Load
type: range
−unit: percent
+unit: '%'
options:
min: 10
…3 unchanged lines
```
−### Voltage dip during the worst case starting step (typically the largest fire pump or chiller) shall not exceed the value selected.
+## Voltage dip during the worst case starting step (typically the largest fire pump or chiller) shall not exceed the value selected.
−### The submittal shall include a starting kVA / voltage dip analysis demonstrating compliance.
+## The submittal shall include a starting kVA / voltage dip analysis demonstrating compliance.
−### The Engineer shall verify both the voltage dip during the largest motor start and the short-circuit current rating of downstream equipment before selecting a low reactance alternator.
+## The Engineer shall verify both the voltage dip during the largest motor start and the short-circuit current rating of downstream equipment before selecting a low reactance alternator.
−### Low reactance alternators reduce voltage dip during motor starting at the cost of higher available short-circuit current, which the downstream equipment must be rated to interrupt. {note}
+## Low reactance alternators reduce voltage dip during motor starting at the cost of higher available short-circuit current, which the downstream equipment must be rated to interrupt. {note}
# Controller {toc}
…15 unchanged lines
- Communication interface (Modbus TCP/IP at a minimum) for integration with the building management system
+### The controller communications protocol shall be as indicated in the datasheet.
+
```datasheet
label: Controller Communications Protocol
…4 unchanged lines
- "BACnet IP"
- "DNP3"
− - "Multiple protocols (specify in submittal)"
+ - "Modbus TCP/IP and BACnet IP"
default: "Modbus TCP/IP (Ethernet)"
```
## NFPA 110 Alarms and Shutdowns {toc}
−```datasheet
−label: NFPA 110 Alarm and Shutdown Configuration
−type: radio
−options:
− - "Level 1 full alarm/shutdown set per NFPA 110 Table 4.7.3"
− - "Level 2 alarm/shutdown set"
−default: "Level 1 full alarm/shutdown set per NFPA 110 Table 4.7.3"
−```
+### The alarm and shutdown set is fully determined by the NFPA 110 Level already selected, so it is stated here as a requirement rather than offered as a second selection. {note}
### The controller shall be configured for the full alarm and shutdown set required by the project Level.
…3 unchanged lines
## Remote Annunciator {toc}
−```datasheet
−label: Remote Annunciator Location
−type: text
−drawing_ref: true
−default: deferred
−```
+### A remote annunciator shall be provided per NFPA 110 4.6.4 at a continuously monitored location outside the generator room, [[drawing: as indicated on the contract documents]].
+### The fire command center, the security desk, and the facility operations room are the usual locations. {note}
+
+### The remote annunciator communication path shall be as indicated in the datasheet.
+
```datasheet
label: Remote Annunciator Communications
type: radio
options:
− - "Dedicated copper run from controller (two separate raceways for Level 1)"
+ - "Dedicated copper run from the controller in two separate raceways"
- "Network-attached (IP) annunciator with redundant link"
−default: "Dedicated copper run from controller (two separate raceways for Level 1)"
+default: "Dedicated copper run from the controller in two separate raceways"
```
−### A remote annunciator shall be provided per NFPA 110 4.6.4 at a location continuously monitored, normally outside the generator room — typically at the building's fire command center, security desk, or facility operations room.
−
### The annunciator shall display all required NFPA 110 alarms with a common audible alarm, a means to silence the audible, and a means to test the lamps.
…4 unchanged lines
## Main Line Circuit Breaker {toc}
+### A main line circuit breaker shall be provided on the generator set output per NEC 445.18, sized for the alternator's rated output.
+
+### The breaker trip unit shall be as indicated in the datasheet.
+
```datasheet
label: Generator Main Line Breaker Trip Unit
type: radio
options:
− - "Thermal-magnetic (smaller sets)"
+ - "Thermal-magnetic"
- "Electronic LSI (Long-time, Short-time, Instantaneous)"
- "Electronic LSIG (with ground fault)"
default: "Electronic LSI (Long-time, Short-time, Instantaneous)"
```
−### A main line circuit breaker shall be provided on the generator set output per NEC 445.18, sized for the alternator's rated output.
+### The breaker shall be molded case or insulated case as appropriate and shall be field-accessible for maintenance and testing.
−### The breaker shall be molded case or insulated case as appropriate, with a thermal-magnetic or electronic trip unit, and shall be field-accessible for maintenance and testing.
+### An electronic trip unit is required wherever the generator breaker participates in a selective coordination study; a thermal-magnetic unit remains acceptable on smaller sets that do not. {note}
# Cooling System {toc}
## The cooling system shall be sized for the engine's full-load heat rejection at the site design ambient, with the air flow path that the enclosure or room imposes.
+## The cooling arrangement shall be as indicated in the datasheet.
+
```datasheet
label: Cooling Arrangement
…8 unchanged lines
## City-water cooling shall not be used for NFPA 110 Level 1 systems because the cooling source must remain available during the same events that may have caused the outage.
−## The default arrangement is a unit-mounted radiator with a blower fan driven by the engine, drawing air from one face of the enclosure and discharging through the radiator; for very large sets, sets in walk-in enclosures with sound attenuation, or sets inside buildings without acceptable air flow, a remote radiator or heat exchanger arrangement may be required. {note}
+## The usual arrangement is a unit-mounted radiator with a blower fan driven by the engine, drawing air from one face of the enclosure and discharging through the radiator; for very large sets, sets in walk-in enclosures with sound attenuation, or sets inside buildings without acceptable air flow, a remote radiator or heat exchanger arrangement may be required. {note}
## Radiator {toc}
+### The radiator fan drive shall be as indicated in the datasheet.
+
```datasheet
label: Radiator Fan Drive
…5 unchanged lines
```
+### The engine coolant shall be as indicated in the datasheet.
+
```datasheet
label: Coolant
type: select
options:
- "50/50 ethylene glycol / water"
− - "Propylene glycol / water (50/50)"
− - "Manufacturer's pre-mixed inhibited coolant"
+ - "50/50 propylene glycol / water"
+ - "Pre-mixed inhibited long-life coolant"
default: "50/50 ethylene glycol / water"
```
−### The radiator shall be sized for the engine manufacturer's published heat rejection at the site ambient with at least 10 deg C margin on coolant outlet temperature.
+### The radiator shall be sized for the engine manufacturer's published heat rejection at the site ambient with at least 10°C margin on coolant outlet temperature.
### Radiator core construction shall be copper-brass or aluminum, with corrosion protection appropriate to the environment.
…11 unchanged lines
## Diesel Fuel Storage {toc}
+### The diesel fuel storage configuration shall be as indicated in the datasheet.
+
```datasheet
label: Diesel Fuel Storage Configuration
type: radio
options:
− - "Sub-base tank (UL 142, single-wall)"
− - "Sub-base tank (UL 142, double-wall with interstitial monitoring)"
− - "Protected sub-base tank (UL 2085, two-hour fire rated)"
− - "External aboveground tank with day tank at generator"
− - "Underground tank with day tank at generator"
−default: "Sub-base tank (UL 142, double-wall with interstitial monitoring)"
+ - "Sub-base tank at the generator"
+ - "External aboveground bulk tank with day tank at the generator"
+ - "Underground bulk tank with day tank at the generator"
+default: "Sub-base tank at the generator"
```
### Sub-Base Fuel Tank {toc}
−#### The default fuel storage configuration is a sub-base tank — a fuel tank constructed as the base of the generator set, listed to UL 142, with interstitial monitoring on double-wall designs. {note}
+#### A sub-base tank is a fuel tank constructed as the base of the generator set, listed to UL 142 or UL 2085, carrying the set's weight and providing its fuel storage in one assembly. {note}
+#### The sub-base tank capacity shall be as indicated in the datasheet.
+
```datasheet
label: Sub-Base Tank Capacity
type: range
unit: gal
−drawing_ref: true
+drawing_ref: "generator schedule"
options:
min: 50
max: 4000
setpoints: [50, 100, 250, 500, 1000, 1500, 2000, 2500, 3000, 4000]
−default: 1000
+default: deferred
```
+#### Tank construction is set by the applicable fire and environmental code, the spill-containment approach, and the AHJ; a UL 2085 protected tank is required where the set sits close to a building or a property line and the AHJ enforces the fire-rated construction provisions of NFPA 30 and NFPA 37. {note}
+
+#### The sub-base tank construction shall be as indicated in the datasheet.
+
```datasheet
label: Sub-Base Tank Construction
…7 unchanged lines
```
−#### Sub-base tanks are practical up to roughly 4,000 gallons (15,000 liters); larger storage typically requires an external bulk tank with a smaller day tank at the set. {note}
+#### Sub-base tanks are practical up to roughly 4,000 gal (15,000 L); larger storage typically requires an external bulk tank with a smaller day tank at the set. {note}
#### The tank capacity shall provide the NFPA 110 Class runtime at the alternator's full-load fuel consumption.
…15 unchanged lines
## Natural Gas and LP Supply {toc}
+### Where a specific gas supply pressure at the generator is required, it shall be as indicated in the datasheet.
+
```datasheet
label: Natural Gas Supply Pressure at Generator
…4 unchanged lines
- "Medium pressure (1 to 5 psig)"
- "Elevated pressure (5 to 15 psig)"
− - "Per engine manufacturer requirement"
−default: "Per engine manufacturer requirement"
+default: manufacturer
```
+### Where no supply pressure is indicated, the engine manufacturer's required inlet pressure range shall govern, and the manufacturer shall state that range in the action submittals.
+
### Where the set is fueled by natural gas or LP, the supply piping shall comply with NFPA 54 (natural gas) or NFPA 58 (LP), be sized for the engine's full-load fuel demand at the worst-case supply pressure, and terminate with a manual shutoff valve and a flexible connector at the engine.
…14 unchanged lines
## Silencer Selection {toc}
+### The exhaust silencer grade shall be as indicated in the datasheet.
+
```datasheet
label: Exhaust Silencer Grade
…4 unchanged lines
- "Critical / Hospital (25 to 35 dB(A) insertion loss)"
- "Super-critical (above 35 dB(A) insertion loss)"
−default: "Critical / Hospital (25 to 35 dB(A) insertion loss)"
```
…6 unchanged lines
## Exhaust Routing {toc}
+### The exhaust shall be routed in seamless steel pipe with welded or flanged joints, supported clear of combustible construction with the clearances of NFPA 37 maintained.
+
+### The exhaust pipe material shall be as indicated in the datasheet.
+
```datasheet
label: Exhaust Pipe Material
…6 unchanged lines
```
+### The extent of exhaust pipe insulation shall be as indicated in the datasheet.
+
```datasheet
label: Exhaust Pipe Insulation
…2 unchanged lines
- "Insulated where exposed within 8 ft of personnel routes"
- "Insulated entire run inside building"
− - "Not insulated (outdoor routing only)"
+ - "Not insulated (fully outdoor routing)"
default: "Insulated entire run inside building"
```
−### The exhaust shall be routed in seamless steel pipe (Schedule 40 carbon steel as the default) with welded or flanged joints, supported clear of combustible construction with the clearances of NFPA 37 maintained, and insulated where exposed to personnel or combustible materials.
+### Exhaust pipe shall be insulated wherever it is exposed to personnel or to combustible materials, whichever extent is selected.
### The discharge shall point away from building air intakes, with the separation from openings in the building required by NFPA 37.
…11 unchanged lines
# Enclosure and Sound Attenuation {toc}
+## The enclosure type shall be as indicated in the datasheet.
+
```datasheet
label: Enclosure Type
…2 unchanged lines
- "Open set (indoor, mechanical room installation)"
- "Weather-protective enclosure (basic outdoor housing)"
− - "Sound-attenuated enclosure (specify dB(A) target)"
+ - "Sound-attenuated enclosure"
- "Walk-in sound-attenuated enclosure"
−default: "Sound-attenuated enclosure (specify dB(A) target)"
```
+## The maximum sound pressure at full load shall be as indicated in the datasheet.
+
```datasheet
label: Maximum Sound Pressure at 7 m (Full Load)
type: range
unit: dB(A)
−drawing_ref: true
+drawing_ref: "generator schedule"
options:
min: 60
max: 85
setpoints: [60, 65, 70, 72, 75, 80, 85]
−default: 75
+default: deferred
```
+## The sound limit is set by the local noise ordinance and the nearest sensitive receptor, so the Engineer records it on the generator schedule rather than the standard preselecting a decibel figure. Unlike transformers, engine generators have no consensus-standard sound table indexed to rating against which a relative limit could be written. {note}
+
## An open set is appropriate where the generator is installed inside a building room dedicated to it and the room provides weather protection, ventilation, and sound attenuation; a weather-protective enclosure is the minimum for outdoor installations, and sound-attenuated and walk-in enclosures incorporate acoustic lining, sound-attenuating intake and discharge openings, and exhaust silencer integration to meet a specified sound limit. {note}
…6 unchanged lines
## Enclosure Construction {toc}
+### The enclosure material shall be as indicated in the datasheet.
+
```datasheet
label: Enclosure Material
…20 unchanged lines
## Starting Batteries {toc}
+### The starting battery type shall be as indicated in the datasheet.
+
```datasheet
label: Battery Type
…5 unchanged lines
```
+### The starting battery system voltage shall be as indicated in the datasheet.
+
```datasheet
label: Battery Voltage
…2 unchanged lines
- "12V"
- "24V"
−default: "24V"
+default: manufacturer
```
+### Where no battery voltage is indicated, the starting system voltage shall be the engine manufacturer's standard for the engine furnished, and the manufacturer shall state it in the action submittals.
+
### Cranking batteries shall be lead-acid (flooded or AGM), sized for the engine manufacturer's required cranking capacity at the design minimum temperature, conforming to EGSA 100B, mounted in a vibration-resistant rack on the set or in the enclosure.
…4 unchanged lines
## Battery Charger {toc}
+### A two-rate (float / equalize), temperature-compensated battery charger listed to UL 1236 shall be provided.
+
+### Where a specific charger output rating is required, it shall be as indicated in the datasheet.
+
```datasheet
label: Battery Charger Rating
−type: select
+type: range
unit: A
options:
− - "5 A (small sets)"
− - "10 A (mid-range)"
− - "20 A (typical)"
− - "Per manufacturer (sized to battery)"
−default: "Per manufacturer (sized to battery)"
+ min: 5
+ max: 20
+ setpoints: [5, 10, 20]
```
−### A two-rate (float / equalize), temperature-compensated battery charger listed to UL 1236 shall be provided.
+### Where no charger rating is indicated, the charger shall be sized to the battery manufacturer's recommended charge rate for the battery furnished, and the rating shall be stated in the action submittals.
### The charger shall maintain the battery at float voltage during normal standby and transition to bulk/absorption charging after an engine start without sulfating the battery on extended floats.
…9 unchanged lines
## Vibration Isolation {toc}
+### The generator set shall be mounted on factory-installed vibration isolators between the engine-alternator skid and the base or sub-base tank.
+
+### The vibration isolation arrangement shall be as indicated in the datasheet.
+
```datasheet
label: Vibration Isolation
…3 unchanged lines
- "Factory isolation plus external spring isolators with seismic restraints"
- "Factory isolation plus restrained spring isolators on inertia base"
−default: "Factory isolation plus external spring isolators with seismic restraints"
```
−### The generator set shall be mounted on factory-installed vibration isolators between the engine-alternator skid and the base or sub-base tank.
−
### Where the set is installed inside an occupied building, additional spring isolators with seismic restraints shall be provided between the base and the housekeeping pad to limit structure-borne noise transmission.
…2 unchanged lines
## Seismic Certification and Anchorage {toc}
+### The seismic certification basis shall be as indicated in the datasheet.
+
```datasheet
label: Seismic Certification Basis
type: select
+drawing_ref: "structural drawings"
options:
- "Not required (no seismic risk)"
…2 unchanged lines
- "ASCE 7 SDC D, E, or F - Importance Factor 1.5 (essential facility)"
- "OSHPD pre-approval (California healthcare)"
−default: "ASCE 7 SDC D, E, or F - Importance Factor 1.0"
+default: deferred
```
+### The Seismic Design Category and Importance Factor are established by the project's structural design and are recorded on the structural drawings; the electrical scope adopts them rather than setting them. {note}
+
### Where seismic certification is required, the complete generator set as assembled — including engine, alternator, controller, sub-base tank, and enclosure — shall be certified by shake-table testing per ICC ES AC156 or by analysis acceptable to the AHJ.
…17 unchanged lines
- Visual and dimensional inspection
+### The extent of factory witness testing shall be as indicated in the datasheet.
+
```datasheet
label: Factory Witness Test
…20 unchanged lines
- Functional test of the exerciser and any load bank interface
+### The field load bank test scope shall be as indicated in the datasheet.
+
```datasheet
label: Field Load Bank Test
…11 unchanged lines
## Commissioning Documentation {toc}
+### The Contractor shall provide a written, signed NFPA 110 installation acceptance test record.
+
+### The witness to the NFPA 110 acceptance test shall be as indicated in the datasheet.
+
```datasheet
label: NFPA 110 Acceptance Test Witness
…4 unchanged lines
- "Engineer of Record witness"
- "Test report certified by Contractor"
−default: "Authority Having Jurisdiction witness required"
```
−### The Contractor shall provide a written, signed NFPA 110 installation acceptance test record.
+### Whether the AHJ elects to witness is the AHJ's determination on each project, so no witness arrangement is preselected here. {note}
### The record shall include the date of test, the technicians performing the test, the instruments used, the measured start time, the load profile, observed alarms, corrective actions if any, and the AHJ witness signature where the AHJ elects to witness.
## Infrared Scanning {toc}
+### The infrared thermographic inspection scope shall be as indicated in the datasheet.
+
```datasheet
label: Infrared Thermographic Inspection
type: radio
options:
- "Initial scan within 90 days plus follow-up at 11 months"
− - "Initial scan within 90 days only"
+ - "Initial scan within 90 days"
- "Not required"
default: "Initial scan within 90 days plus follow-up at 11 months"
```
−### An infrared thermographic scan of all power terminations and bus connections shall be performed under full load within 90 days of energization, with a follow-up scan at 11 months to capture any connections that loosen during initial thermal cycling.
+### Each scheduled scan shall cover all power terminations and bus connections and shall be performed under full load.
−### Connections showing more than 10 deg C rise above ambient or 5 deg C rise above similar adjacent connections shall be corrected.
+### The follow-up scan at 11 months catches connections that loosen during the first year of thermal cycling, while the equipment is still under warranty. {note}
+### Connections showing more than 10°C rise above ambient or 5°C rise above similar adjacent connections shall be corrected.
+
# Installation {toc}
…10 unchanged lines
## Clearances {toc}
+### The service clearance provided around the set shall be as indicated in the datasheet.
+
```datasheet
label: Service Clearance Around Set
type: select
options:
− - "Per manufacturer's recommendation (typically 3 ft on service sides)"
− - "Per NFPA 70 110.26 (electrical working space) - minimum"
+ - "NFPA 70 110.26 working space minimum"
+ - "The greater of NFPA 70 110.26 and the engine manufacturer's published service access requirement"
- "Walk-around access on all four sides"
−default: "Per manufacturer's recommendation (typically 3 ft on service sides)"
```
+### The codes set a floor; the clearance actually provided is a site-planning decision, and walk-around access on all four sides is frequently specified where the Owner's maintenance staff services the set in place, so the field carries no default. {note}
+
### Working clearances around the generator set and its controller, transfer switch, and main line breaker shall comply with NFPA 70 Article 110.26.
…2 unchanged lines
## Conduit, Cable, and Grounding {toc}
+### The generator neutral treatment shall be as indicated in the datasheet.
+
```datasheet
label: Generator Neutral Treatment
type: radio
+drawing_ref: "one-line diagram"
options:
- "Switched neutral at ATS - generator is a separately derived system"
- "Solid (non-switched) neutral at ATS - generator is not separately derived"
−default: "Solid (non-switched) neutral at ATS - generator is not separately derived"
+default: deferred
```
…20 unchanged lines
# Identification and Labeling {toc}
+## Field-installed labels shall be provided as indicated in the datasheet.
+
```datasheet
label: Generator Identification
…6 unchanged lines
- "NFPA 110 Level and Type identification at the set"
- "Emergency power source identification at served panelboards"
−default: "Equipment designation matched to one-line diagram"
+default:
+ - "Equipment designation matched to one-line diagram"
+ - "EPS supply identification per NEC 700.10(A) (emergency systems)"
+ - "Available fault current label per NEC 110.24"
+ - "Arc flash warning label per NFPA 70E and IEEE 1584"
+ - "NFPA 110 Level and Type identification at the set"
```
…16 unchanged lines
# Warranty {toc}
+## The manufacturer shall warrant each generator set for the period indicated in the datasheet.
+
```datasheet
label: Warranty Period
…3 unchanged lines
- "2 years / 1,000 hours, whichever occurs first"
- "5 years / 1,500 hours extended (premium)"
− - "Custom (specify in submittal)"
default: "2 years / 1,000 hours, whichever occurs first"
```
…7 unchanged lines
# Spare Parts and Maintenance Materials {toc}
+## Spare parts shall be furnished as indicated in the datasheet.
+
```datasheet
label: Spare Parts Package
…2 unchanged lines
- "One set of engine filters (oil, fuel, air, coolant)"
- "One set of belts and hoses"
− - "Spare set of alternator brushes (where applicable)"
- "Spare battery (matched to installed set)"
- "Spare control fuses and indicating lamps"
- "Touch-up paint matching enclosure finish"
−default: "One set of engine filters (oil, fuel, air, coolant)"
+default:
+ - "One set of engine filters (oil, fuel, air, coolant)"
+ - "One set of belts and hoses"
+ - "Spare control fuses and indicating lamps"
+ - "Touch-up paint matching enclosure finish"
```
…4 unchanged lines
## Owner Training {toc}
+### The generator manufacturer's authorized service representative shall provide on-site training to the Owner's operating personnel for the duration indicated in the datasheet, and in no case less than four hours.
+
```datasheet
label: Owner Training Duration
−type: select
+type: range
+unit: hours
options:
− - "4 hours (minimum)"
− - "8 hours (split between operations and maintenance)"
− - "16 hours (operations, maintenance, and troubleshooting)"
−default: "8 hours (split between operations and maintenance)"
+ min: 4
+ max: 16
+ setpoints: [4, 8, 16]
+default: 8
```
−### The generator manufacturer's authorized service representative shall provide a minimum of four hours of on-site training to the Owner's operating personnel.
+### An 8-hour session shall be split between operations and maintenance, and a 16-hour session shall be split between operations, maintenance, and troubleshooting.
### Training shall cover normal operation, the controller interface, the exerciser configuration, the alarm and shutdown response procedure, NFPA 110 testing and recordkeeping, and routine maintenance intervals.