SCXF-SVX01B-EN 27
Electrical
Requirements
Table I-ER-6. Electric Heat - Single Stage
SCWF SCRF Heat 200V 460V
Size Size Kw Amps Amps
20 - 18 50 21.7
22 - 18 50 21.7
25 20 18 50 21.7
29 25 23 63.8 27.7
32 29 23 63.8 27.7
35 30 27 75 32.5
38 35 27 75 32.5
42 - 31.5 87.4 37.9
46 40 31.5 87.4 37.9
52 - 39 108.3 46.9
58 50 39 108.3 46.9
65 - 48 133.2 57.7
72 - 48 133.2 57.7
80 60 48 133.2 57.7
Note: Electric heat amperage should not be considered when determining minimum circuit ampacity. The current of the
unit in the heating mode will not exceed the current of the unit in the cooling mode.
Selection Procedures
RLA = Rated Load Amps
Compressor LRA = Locked Rotor Amps
Fan Motor LRA = Locked Rotor Amps,
N.E.C. Table 430 - 150
FLA = Full Load Amps, N.E.C.
Table 430 - 150
Voltage utilization range is ±10 percent
Determination of minimum circuit
ampacity (MCA).
MCA = 1.25 x largest motor amps/VFD
amps (FLA or RLA) + the sum of the
remaining motor amps.
Determination of maximum fuse size
(MFS) and maximum circuit breaker size
(MCB).
MFS and MCB = 2.25 x largest motor
amps (FLA or RLA) + the sum of the
remaining motor amps.
For units with the dual power option,
there are two electrical circuits that need
calculations using the formulas above:
circuit #1 - fans
circuit #2 - compressors
If the rating value determined does not
equal a standard current rating of over
current protective device, use the next
lower standard rating for the marked
maximum rating.
Table I-ER-1. Number of Compressors per Unit
SCRF/SIRF 20 25 - 29 30 - 35 40 50 60
SCWF/SIWF 20 - 25 29 - 32 35 - 38 42 - 46 52 - 58 65 - 72 80
10 2 1 3 2 - 1 -
15 - 1 - 1 3 3 4
Table I-ER-2. SCWF/SIWF Compressor Electrical Data
200V460V575V
HP RLA LRA RLA LRA RLA LRA
10 33 269 14.5 117 11.5 94
15 46 409 20.5 178 16.5 143
Table I-ER-3. SCRF/SIRF Compressor Electrical Data
200V 460V 575V
HP RLA LRA RLA LRA RLA LRA
10 36.8 269 16.3 117 13.2 94
15 61.1 409 26 178 21.5 143
Table I-ER-4. Fan without VFD Data
200V 460V 575V
HP FLA LRA FLA LRA FLA LRA
5 16.1 105 6.7 46 5.4 37
7.5 25.0 152 10.8 66 8.2 54
10 32.9 193 14.2 84 11.4 66
15 44.8 290 20.3 126 16.2 102
20 61.0 373 25.0 162 20.0 132
25 74.0 469 31.0 204 24.2 162
30 87.0 552 36.0 240 28.6 192
40 113.0 718 47.8 312 38.0 246
50 NA NA 62.0 390 49.2 312
Table I-ER-5. Fan with VFD
200V 460V
HP FLA LRA FLA LRA
7.5 29.4 152 13.9 66
10 37.9 193 17.6 84
15 51.4 290 24.8 126
20 66.5 373 31.9 162
25 91.4 469 44 204
30 91.4 552 44 240
40 116.0 718 57.1 312
50 NA NA 68.3 390
Installation