Bryant DURAPAC 579F User Manual
Page 12
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12
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Table 5 — Electrical Data
LEGEND
*Fuse or HACR circuit breaker.
NOTES:
1. In compliance with NEC requirements for multimotor and combina-
tion load equipment (refer to NEC Articles 430 and 440), the overcur-
rent 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 voltage imbalance.
% Voltage Imbalance
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
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.
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 the local electric utility company immediately.
UNIT
579F
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*
180
(15 Tons)
208/230
187
253
25.6
190
25.6
190
3
0.5
1.7
3.7 10.5/11.0
—
—
0.57
74/74
90/ 90
4.6
18.8
0.57
78/79
100/100
460
414
508
13.5
95
13.5
95
3
0.5
0.8
3.7
4.8
—
—
0.30
38
50
2.3
6.0
0.30
40
50
216
(18 Tons)
208/230
187
253
33
237
23
184
3
0.5
1.7
5.0 15.8/15.8
—
—
0.57
85/85
110/110
4.6
18.8
0.57
90/90
110/110
460
414
508
16.2
130
10.2
90
3
0.5
0.8
5.0
7.9
—
—
0.30
41
50
2.3
6.0
0.30
43
50
240
(20 Tons)
208/230
187
253
33
237
29.5
237
2
1
6.6
7.5 25.0/25.0
—
—
0.57
109/109 125/125
4.6
18.8
0.57
114/114 125/125
460
414
508
16.2
130
14.1
130
2
1
3.3
7.5
13.0
—
—
0.30
54
70
2.3
6.0
0.30
56
70
300
(25 Tons)
208/230
187
253
47.5
265
33.0
237
2
1
6.6
10.0 28.0/28.0
—
—
0.57
134/134 175/175
4.6
18.8
0.57
135/135 175/175
460
414
508
22.9
145
16.2
130
2
1
3.3
10.0
14.6
—
—
0.30
66
80
2.3
6.0
0.30
68
90
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, U.S.A.
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
=
457
% Voltage Imbalance = 100 x
7
457
= 1.53%