Communication Server Large System Installation and Commissioning

Page 112 of 456 Installing DC power
NN43021-310 Standard 02.01 December 2007
Note 1: The frame ground collector cable is normally sized according to
its length (distance between the main DC distribution cabinet and the
FGB or BPG) as well as the maximum fuse or circuit breaker size that
can be provided in the power plant. Refer to Table 3 for the
recommended cable size for the Candeo power system.
Note 2: The frame ground drop into the Candeo frame must be the same
size as the frame ground collector. The frame ground drop into battery
stands, racks or stacks is usually #6 AWG.
Table 3
Recommended cable size for the frame ground collector
Cable length
Recommended size
(see notes 1 and 2 above)
0 to 6 m (0 to 20 ft) #2 AWG
6 to 12 m (20 to 40 ft) #0 AWG
12 to 24 m (40 to 80 ft) #0000 AWG
24 to 50 m (80 to 160 ft) #500 kcmil
Table 4
Torque values for bolted connections (Part 1 of 2)
Bolt size Threads/inch Torque (in.-lb) Tension (lb)
#8 32
36
18
20
625
685
#10 24
32
23
32
705
940
6 mm (1/4 in.) 20
28
80
100
1840
2200
8 mm (5/16 in.) 18
20
140
150
2540
2620
9.5 mm (3/8 in.) 16
24
250
275
3740
3950