Trane CenTraVac CDHH - Current Transformer and Potential; Transformer Wire Sizing

CDHH-SVX003C-EN
57
Current Transformer and
Potential Transformer Wire
Sizing
For customer-supplied starter-to-chiller unit control panel
starter module 1K23; these wires must be separated from
120 Vac or higher wiring.
Table 19. Maximum recommended wire length for
secondary current transformer (CT) leads in
dual CT system
Wire AWG
(a)
Maximum Wire Length
Secondary CT Leads
Feet Meters
8 1362.8 415.5
10 856.9 261.2
12 538.9 164.3
14 338.9 103.3
16 213.1 65.0
17 169.1 51.5
18 134.1 40.9
20 84.3 25.7
Notes:
1. For AWG/MCM equivalents in mm
2
, refer to the table in “Electrical
Requirements,” p. 53.
2. Wire length is for copper conductors only.
3. Wire length is total one-way distance that the CT can be from the starter
module.
(a)
Wires, lugs, and fuses/breakers are sized based on National Electric Code
(NEC) [NFPA 70] and UL 1995.
Table 20. Maximum recommended total wire length
for potential transformers (PTs) in a single
PT system
Wire AWG
(a)
Maximum Lead Length
Feet Meters
8 5339 1627
10 3357 1023
12 2112 643
14 1328 404
16 835 254
17 662 201
18 525 160
20 330 100
21 262 79
22 207 63
Notes:
1. For AWG/MCM equivalents in mm
2
, refer to the table in “Electrical
Requirements,” p. 53.
2. Wire length is for copper conductors only.
3. Wire length is maximum round trip wire length. The maximum distance
the PT can be located from the starter module is half of the listed value.
(a)
Wires, lugs, and fuses/breakers are sized based on National Electric Code
(NEC) [NFPA 70] and UL 1995.
Table 21. Maximum recommended total wire length
(to and from) for PT leads in a dual PT
system
Wire AWG
(a)
Max Wire Length Primary
Max Wire Length
Secondary
Feet Meters Feet Meters
8 3061 933 711 217
10 1924 586 447 136
12 1211 369 281 85
14 761 232 177 53
16 478 145 111 33
17 379 115 88 26
18 301 91 70 21
20 189 57 44 13
21 150 45 34 10
22 119 36 27 8
Notes:
1. For AWG/MCM equivalents in mm
2
, refer to the table in “Electrical
Requirements,” p. 53.
2. Wire length is for copper conductors only.
3. Wire length is maximum round trip wire length. The maximum distance
the PT can be located from the starter module is half of the listed value.
(a)
Wires, lugs, and fuses/breakers are sized based on National Electric Code
(NEC) [NFPA 70] and UL 1995.
Customer-supplied Remote Starter Wiring