UFC 4-171-05
1 January 2005
with change 25 October 2006
3-10.3.1.7 The following minimum loads should be assumed to determine the
preliminary size of electrical service to the building:
Lighting Load
3 VA/sf (26.9VA/sq m)
Site Lighting
465 VA per fixture
HVAC Load
6.5 VA/sf (64.6 VA/sq m)
Elevator
40 HP/elevator
Computer Load
1.0 VA/sf (10.8 VA/sq m)
General Purpose
0.5 VA/sf (5.4 VA/sq m)
Receptacles
Miscellaneous Loads
1.0 VA/sf (10.8 VA/sq m)
Future Spare Capacity
+25%
Minimum Power Factor
0.9
Transformer Impedance
5.75%
3-10.3.2 Power
3-10.3.2.1 All motors 1/2 HP and larger should be specified 3-phase 480 volts when
available. Provide overload protection in the motor starters and short circuit protection
for the motor and its feeder. \ When there is a problem obtaining equipment with 480
volt, 3 phase power, request a deviation from the Contracting Officer s Representative
to provide equipment at another voltage./2/
3-10.3.2.2 \ Include single phase protection where 120V/240V /2/ motors are
required by code to have thermal protection, manual thermal overload starters should
be provided.
3-10.3.2.3
Disconnect switches should be provided for all motors and equipment.
3-10.3.2.4 A Motor Control Center shall be considered to be provided in the
Mechanical room where 4 or more polyphase motor starters are required.
3-10.3.2.5 In branch circuit, feeder and service calculations, compute receptacle
loads at not more than 180 volt-amperes per outlet with demand factors according to
NFPA 70 Article 220.
3-10.3.2.6 All general purpose receptacles should be 20 amps, NEMA WD 1. Ground
fault circuit interrupter receptacles should be provided for bathrooms, maintenance bays
and outdoor receptacles. Recessed floor outlets in the first floor and poke-through
outlets on second and third floor should be provided to connect freestanding
workstations in the open office areas. Provide multiple convenience receptacles
adjacent to desk locations in individual and shared offices.
3-10.3.2.7
Light switches should be 20 amp, 120/277 volt AC, specification grade.
3-10.3.2.8 \ If 4 (four) or more 3-phase motors are located within a room or area
use a motor control center (MCC) for motors requiring a starter. /2/
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