Page 120 of 456 Installing DC power
A maximum loop drop of 2 V is allowed between the pedestal, or junction box, and the external power equipment. See Table 5 for allowable wire sizes. See Communication Server 1000M and Meridian 1: Large System Planning and Engineering
Table 5
Wire gauge requirements with two 30 A feeds (five wires)
Length | #8 AWG | #6 AWG | Single #4 AWG | Double #4 AWG |
|
|
|
|
|
0 to 3 m (10 ft) | Yes | Yes | Yes | Yes |
3 to 6 m (20 ft) | Yes | Yes | Yes | Yes |
6 to 9 m (30 ft) | Yes | Yes | Yes | Yes |
9 to 12 m (40 ft) | Yes | Yes | Yes | Yes |
12 to 15 m (50 ft) | Yes | Yes | Yes | Yes |
15 to 18 m (60 ft) | No | Yes | Yes | Yes |
18 to 21 m (70 ft) | No | Yes | Yes | Yes |
21 to 24 m (80 ft) | No | Yes | Yes | Yes |
24 to 27 m (90 ft) | No | No | Yes | Yes |
27 t o 30 m | No | No | Yes | Yes |
(100 ft) |
|
|
|
|
30 to 60 m | No | No | No | Yes |
(200 ft) |
|
|
|
|
over 60 m (200 ft) | No | No | No | No |
Note 1: Two 30 A feeds are typically adequate for a column with four modules (five wires
Note 2: If dual conduit is used, the wires must be run in battery/battery return pairs, with one pair in one conduit and the other pair, plus logic return, in the other conduit.
Legend:
Yes = Wire size is adequate for the distance.
No = Wire size has too high a voltage drop and is inadequate for the distance.
