Electrical data – Bryant 581C User Manual
Page 275
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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
581
A1
55
-30
0