Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Common Motor Requirements for Electrical Equipment
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motors certified integral to listed packaged equipment by that equipment's
specification; branch-circuit conductors (sync/conductors-and-cables); and
− upstream distribution (sync/low-voltage-panelboards, sync/low-voltage-switchboards).
+ upstream distribution (sync/panelboards, sync/low-voltage-switchboards).
---
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- Motors certified by the equipment manufacturer as part of a factory-tested listed package (chillers, rooftop units, packaged pumps), which are governed by the respective equipment specification.
- Branch-circuit conductors and cables from the motor terminals to the controller - see [[sync/conductors-and-cables]].
−- Power distribution upstream of the motor branch circuit - see [[sync/low-voltage-panelboards]] and [[sync/low-voltage-switchboards]].
+- Power distribution upstream of the motor branch circuit - see [[sync/panelboards]] and [[sync/low-voltage-switchboards]].
# Referenced Standards {toc}
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## Motors installed above 3,300 ft (1,000 m) shall be derated, or furnished with a special winding, such that the temperature rise at the installed elevation does not exceed the limit for the insulation class.
−## Altitude derating is commonly missed because manufacturers quote standard catalog data; for mountain-region projects above 3,300 ft the temperature-rise margin shrinks roughly 3% per 500 m of elevation and must be verified in the submittal. {note}
+## Altitude derating is commonly missed because manufacturers quote standard catalog data; for mountain-region projects above 3,300 ft the temperature-rise margin shrinks roughly 3% per 500 m of elevation and must be verified in the submittal.
## The applied voltage shall not vary more than ±10% of nameplate voltage, and the applied frequency shall not vary more than ±5% of nameplate frequency; the combined voltage and frequency variation shall not exceed 10% per NEMA MG 1 Section 12.44.
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## The motor design letter shall be coordinated with the driven load so that the available starting torque exceeds the load torque throughout acceleration.
−## Specifying NEMA Design B for a hard-starting load such as a loaded conveyor or positive-displacement pump risks stall; verify starting-torque adequacy and specify Design C or D where the load demands it. {note}
−
```datasheet
label: NEMA design letter
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```
+## Specifying NEMA Design B for a hard-starting load such as a loaded conveyor or positive-displacement pump risks stall; verify starting-torque adequacy and specify Design C or D where the load demands it. {note}
+
# Efficiency {toc}
## Motors 1 HP through 500 HP shall be NEMA Premium (IE3) efficiency unless the Contract Documents require NEMA Premium 4 (IE4).
−## Nominal full-load efficiency shall meet or exceed the value listed in ASHRAE 90.1 Table 10.8-1 for the motor's horsepower, pole count, and enclosure.
−
−## Representative NEMA Premium minimum efficiencies for 4-pole, 460 V, TEFC motors are 91.7% at 10 HP, 94.5% at 50 HP, 95.0% at 100 HP, and 95.4% at 200 HP. {note}
−
−## Failing to require an IEEE 112 Method B certified efficiency report means ASHRAE 90.1 and EISA compliance cannot be confirmed at equipment approval; the report is the only verifiable proof at submittal time. {note}
−
```datasheet
label: Efficiency class
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```
+## Nominal full-load efficiency shall meet or exceed the value listed in ASHRAE 90.1 Table 10.8-1 for the motor's horsepower, pole count, and enclosure.
+
+## Representative NEMA Premium minimum efficiencies for 4-pole, 460 V, TEFC motors are 91.7% at 10 HP, 94.5% at 50 HP, 95.0% at 100 HP, and 95.4% at 200 HP. {note}
+
+## Failing to require an IEEE 112 Method B certified efficiency report means ASHRAE 90.1 and EISA compliance cannot be confirmed at equipment approval; the report is the only verifiable proof at submittal time. {note}
+
# Enclosure {toc}
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## Motors above 200 HP and high-speed motors shall have external grease fittings with relief provisions.
−## The conduit box shall be rotatable in 90-degree increments where the motor orientation is not fixed at the time of bid, so conduit can enter cleanly without a change order. {note}
+## The conduit box shall be rotatable in 90-degree increments where the motor orientation is not fixed at the time of bid, so conduit can enter cleanly without a change order.
## The conduit box shall be sized to accept the branch-circuit raceway furnished under [[sync/raceways-and-conduit]] and the conductors furnished under [[sync/conductors-and-cables]], with motor leads not less than 18 in long.
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## All testing and commissioning shall be performed under an electrical safety program complying with NFPA 70E, with arc-flash and shock protection appropriate to the available incident energy. {note}
+## The field acceptance tests required for each motor shall be specified, and all testing and commissioning shall be performed under an NFPA 70E electrical safety program.
+
```datasheet
label: Field acceptance tests required
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- Manufacturer's recommended spares list
```