Carrier 38AU Installation, Start-Up And Service Instructions Manual page 22

NOMINAL
POWER
UNIT
SUPPLY
SIZE
38AU
V--- Ph--- Hz
208/230---3---60
D*16
460 ---3 ---60
Z*16
575 ---3 ---60
208/230---3---60
D*25
460 ---3 ---60
Z*25
575 ---3 ---60
NOMINAL
POWER
UNIT
SUPPLY
SIZE
38AU
V--- Ph--- Hz
208/230---3---60
D*16
460 ---3 ---60
Z*16
575 ---3 ---60
208/230---3---60
D*25
460 ---3 ---60
Z*25
575 ---3 ---60
Legend and Notes for Table 10
LEGEND:
BRKR --- Circuit breaker
CO --- Convenient outlet
FLA --- Full Load Amps
LRA --- Locked Rotor Amps
MCA --- Minimum Circuit Amps
Protection
NEC --- National Electrical Code
PWRD CO --- Powered convenient outlet
RLA --- Rated Load Amps
UNPWR CO --- Unpowered convenient outlet
NOTES:
1. In compliance with NEC requirements for multimotor and
combination load equipment (refer to NEC Articles 430 and
440), the overcurrent protective device for the unit shall be
fuse or HACR breaker. Canadian units may be fuse or circuit
breaker.
2. The MCA values are calculated in accordance with The NEC.
Article 440.
3. Motor RLA and LRA values are established in accordance
with Underwriters' Laboratories (UL). Standard 1995.
4. The 575--- v units are UL, Canada--- listed only.
5. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply
voltage is greater than 2%. Use the following formula to de-
termine the percentage of voltage imbalance.
Table 10 – Unit Wire/Fuse or HACR Breaker Sizing Data
COMPRESSOR
VOLTAGE
RANGE
No. 1
Min Max RLA LRA RLA
187 253 25.0 164 25.0
414 506 12.2 100 12.2
518 633 9.0 78 9.0
187 253 30.1 225 30.1
414 506 16.7 114 16.7
518 633 12.2 80 12.2
COMPRESSOR
VOLTAGE
RANGE
No. 1
Min Max RLA LRA RLA
187 253 25.0 164 25.0
414 506 12.2 100 12.2
518 633 9.0 78 9.0
187 253 30.1 225 30.1
414 506 16.7 114 16.7
518 633 12.2 80 12.2
NO C.O. or UNPWRD C.O.
No. 2 OFM POWER SUPPLY
FLA
LRA Qty MCA
(ea)
164 3 1.5 60.8/60.8
100 3 0.8 29.9
78 3 0.7 22.4
225 4 1.5 73.7/73.7
114 4 0.8 40.8
80 4 0.7 30.3
No. 2 OFM POWER SUPPLY
FLA
LRA Qty MCA
(ea)
164 3 1.5 65.6/65.6
100 3 0.8 32.1
78 3 0.7 24.1
225 4 1.5 78.5/78.5
114 4 0.8 43
80 4 0.7 32
Example: Supply voltage is 230-3-60
% Voltage Imbalance = 100 x
AB = 224 v
BC = 231 v
AC = 226 v
(224 + 231 + 226)
Average Voltage =
=
Determine maximum deviation from average voltage.
(AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v
(AC) 227 – 226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% Voltage Imbalance
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
22
DISCONNECT SIZE
FUSE or
HACR FLA LRA
BRKR
80/80 63/63 337/337
40 31 206
30 23 162
100/100 76/76 462/462
50 42 236
40 31 168
w/ PWRD C.O.
DISCONNECT SIZE
FUSE or
HACR FLA LRA
BRKR
90/90 68/68 342/342
40 33 208
30 25 164
100/100 82/82 467/467
50 45 238
40 33 170
max voltage deviation from average voltage
average voltage
=
3
227
4
= 100 x
227
= 1.76%
681
3