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Wiring Inspection
26
9.0 WIRING INSPECTION
1. Verify all power connections are tightened per the torque specifications in Table 3.
2. Verify all control wire terminations are tight.
3. Verify all power wires and connections have proper spacing between exposed surfaces, phase-to-
phase and phase-to-ground.
4. Verify that all control wires are run in steel conduit, separate from all power wiring.
Use 75°C copper wire. Select wire size based on the ampacities in Table 5 of this manual, a reprint of
Table 310-16 and associated notes of the National Electrical Code (NFPA 70).
Use commercially available solderless lugs for the wire size required for your application. Refer to
Table 3. Connect wire to the lug using tools and procedures specified by the lug manufacturer.
Table 2 Power wiring terminals - factory supplied
UPS Module Rating Connection Type
500-750kVA
Busbars for connecting hardware (with 3/8” holes on 1.75” centers) are provided for bypass
input, critical load output and DC wiring terminations. DC busbars for 625-750kVA modules
are designed for top entry and are located adjacent to the input circuit breaker. Rectifier
input wiring is top-entry, directly to lugs on top of the input circuit breaker. Field-supplied
lugs are required.
EXCEPTION: 500kVA UPS modules with the 6-pulse rectifier and no input isolation
transformer have rectifier input busbars exactly like those described above for bypass and
critical load termination.
Table 3 Torque specifications
NUT AND BOLT COMBINATIONS
Bolt Shaft Size
Grade 2 Standard
Electrical Connections
with Belleville Washers
Lb-in N-m Lb-in N-m
1/4 53 6.0 46 5.2
5/16 107 12 60 6.8
3/8 192 22 95 11
1/2 428 22 256 29
CIRCUIT BREAKERS WITH COMPRESSION LUGS (FOR POWER WIRING)
Wire Size or Range Lb-in N-m
#6 - #4 100 11
#3 - #1 125 14
1/0 - 2/0 150 17
3/0 - 200 MCM 200 23
250 - 400 MCM 250 28
500 - 700 MCM 300 34
CIRCUIT BREAKERS WITH COMPRESSION LUGS (FOR POWER WIRING)
Current Rating Lb-in N-m
400 - 1200 Amps 300.00 34.00
TERMINAL BLOCK COMPRESSION LUGS (FOR CONTROL WIRING)
AWG Wire Size or Range Lb-in N-m
#22 -#14 3.5 to 5.3 0.4 to 0.6
NOTE: Use the values in this table unless the equipment is labeled with a different torque value.