Bryant 581A Installation And Service Instructions Manual page 10

NOMINAL
VOLTAGE
UNIT VOLTAGE
RANGE
581A (3 Ph, 60
Min
Hz)
208/230 187
015
(Standard
IFM)
460 414
208/230 187
015
(Optional
IFM)
460 414
208/230 187
017
460 414
208/230 187
025
460 414
LEGEND
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
*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 voltage imbalance.
% Voltage Imbalance
max voltage deviation from average voltage
= 100 x
average voltage
Table 2 — Electrical Data
COMPRESSOR
No. 1 No. 2
Max RLA LRA RLA
253 20.7 156 19.3
508 10 70 10
253 20.7 156 19.3
508 10 70 10
253 32.1 195 20.7
508 16.4 95 10
253 42 239 33.6
508 19.2 125 17.3
OFM
LRA Qty Hp FLA (ea) Hp
123 3 0.5 1.7 2.9
62 3 0.5 0.8 2.9
123 3 0.5 1.7 3.7
62 3 0.5 0.8 3.7
156 3 0.5 1.7 5.0
70 3 0.5 0.8 5.0
225 2 1 6.6 7.5
114 2 1 3.3 7.5
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
452 + 464 + 455
Average Voltage =
1371
=
= 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 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%, contact your local electric
utility company immediately.
—10—
POWER COMBUSTION
IFM
EXHAUST FAN MOTOR
FLA FLA LRA FLA
8.8/ — — 0.57
8.4 4.6 18.8 0.57
— — 0.30
4.2
2.3 6.0 0.30
11.0/ — — 0.57
10.5 4.6 18.8 0.57
— — 0.30
4.8
2.3 6.0 0.30
15.8/ — — 0.57
15.8 4.6 18.8 0.57
— — 0.30
7.9
2.3 6.0 0.30
25.0/ — — 0.57
25.0 4.6 18.8 0.57
— — 0.30
13.0
2.3 6.0 0.30
3
3
7
457
POWER
SUPPLY
MCA MOCP*
59/59 70/70
64/63 80/80
29 35
31 40
61/61 80/80
66/65 80/80
30 35
32 40
82/82 110/110
86/86 110/110
41 50
43 50
124/124 150/150
129/129 150/150
61 80
63 80