Table 2 — electrical data – Bryant SINGLE PACKAGE ROOFTOP ELECTRIC COOLING/GAS HEATING UNITS 581A User Manual
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Table 2 — Electrical Data
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 voltage 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 voltage imbalance.
= 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.
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*
015
(Standard
IFM)
208/230
187
253
20.7 156
19.3
123
3
0.5
1.7 2.9
8.8/
8.4
—
4.6
—
18.8
0.57
0.57
59/59
64/63
70/70
80/80
460
414
508
10
70
10
62
3
0.5
0.8
2.9
4.2
—
2.3
—
6.0
0.30
0.30
29
31
35
40
015
(Optional
IFM)
208/230
187
253
20.7
156
19.3
123
3
0.5
1.7
3.7
11.0/
10.5
—
4.6
—
18.8
0.57
0.57
61/61
66/65
80/80
80/80
460
414
508
10
70
10
62
3
0.5
0.8
3.7
4.8
—
2.3
—
6.0
0.30
0.30
30
32
35
40
017
208/230
187
253
32.1
195
20.7
156
3
0.5
1.7
5.0
15.8/
15.8
—
4.6
—
18.8
0.57
0.57
82/82
86/86
110/110
110/110
460
414
508
16.4
95
10
70
3
0.5
0.8
5.0
7.9
—
2.3
—
6.0
0.30
0.30
41
43
50
50
025
208/230
187
253
42
239
33.6
225
2
1
6.6
7.5
25.0/
25.0
—
4.6
—
18.8
0.57
0.57
124/124
129/129
150/150
150/150
460
414
508
19.2
125
17.3
114
2
1
3.3
7.5
13.0
—
2.3
—
6.0
0.30
0.30
61
63
80
80
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
% Voltage Imbalance = 100 x
7
457