275
ELECTRICAL DATA — 581A (cont)
ELECTRICAL DATA — 581A155,180
LEGEND
*Fuse or HACR circuit breaker.
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. 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 determine the percent of volt-
age imbalance.
% Voltage Imbalance
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
= 457
Determine maximum deviation from average voltage.
(AB) 457 – 452 = 5 v
(BC) 464 – 457 = 7 v
(AC) 457 – 455 = 2 v
Maximum deviation is 7 v.
Determine percent of voltage imbalance.
% Voltage Imbalance = 100 x
= 1.53%
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%, con-
tact your local electric utility company immediately.
UNIT
581A
NOMINAL
VOLTAGE
(3 Ph, 60 Hz)
VOLTAGE
RANGE COMPRESSOR OFM IFM POWER
EXHAUST COMBUSTION
FAN MOTOR POWER
SUPPLY
No. 1 No. 2
Min Max RLA LRA RLA LRA Qty Hp FLA (ea) Hp FLA FLA LRA FLA MCA MOCP*
155
(Standard
IFM)
208/230 187 253 20.7 156 20.7 156 3 0.5 1.70 2.9 8.8/ 8.4 — — 0.57 60/60 80/80
4.6 18.8 0.57 65/65 80/80
460 414 506 10.0 75 10.0 75 3 0.5 0.80 2.9 4.2 — — 0.30 29 35
2.3 6.0 0.30 31 40
575 518 633 8.2 54 8.2 54 3 0.5 0.75 3.0 3.9 — — 0.57 25 30
2.1 4.8 0.57 27 30
155
(Optional
IFM)
208/230 187 253 20.7 156 20.7 156 3 0.5 1.70 3.7 10.5/11.0 — — 0.57 62/63 80/80
4.6 18.8 0.57 67/67 80/80
460 414 506 10.0 75 10.0 75 3 0.5 0.80 3.7 4.8 — — 0.30 30 35
2.3 6.0 0.30 32 40
180
208/230 187 253 32.1 195 20.7 156 3 0.5 1.70 5.0 15.8/15.8 — — 0.57 82/82 110/110
4.6 18.8 0.57 86/86 110/110
460 414 506 16.4 95 10.0 75 3 0.5 0.80 5.0 7.9 — — 0.30 41 50
2.3 6.0 0.30 43 50
575 518 633 12.0 80 8.2 54 3 0.5 0.75 5.0 6.0 — — 0.57 31 40
2.1 4.8 0.57 34 45
FLA — Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
IFM — Indoor (Evaporator) Fan Motor
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC — National Electrical Code
OFM — Outdoor (Condenser) Fan Motor
RLA — Rated Load Amps
= 100 x max voltage deviation from average voltage
average voltage
Average Voltage =452 + 464 + 455
3
= 1371
3
7
457
581A155-300