Electrical data, 79 electrical data – Bryant 581C User Manual
Page 79
79
ELECTRICAL DATA
LEGEND
*Used to determine minimum disconnect per NEC.
†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 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 of 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.
3. For units with power exhaust: If a single power source is to be used, size wire to include
power exhaust MCA and MOCP. Check MCA and MOCP when power exhaust is powered
through the unit (must be in accordance with NEC and/or local codes). Determine the new
MCA including the power exhaust using the following formula:
MCA New = MCA unit only + MCA of Power Exhaust
For example, using a 580F060 unit with MCA = 28.9 and MOCP = 35, with
CRPWREXH030A01 power exhaust.
MCA New = 28.9 amps + 1.6 amps = 30.5 amps
If the new MCA does not exceed the published MOCP, then MOCP would not change. The
MOCP in this example is 35 amps, the MCA New is below 35, therefore the MOCP is
acceptable. If “MCA New” is larger than the published MOCP, raise the MOCP to the next
larger size. For separate power, the MOCP for the power exhaust will be 15 amps per NEC.
POWER EXHAUST ELECTRICAL DATA
*Single or three phase.
UNIT SIZE
580F
NOMINAL
V-PH-Hz
IFM
TYPE
CONV
OUTLET
VOLTAGE
RANGE
COMPRESSOR (each)
OFM (each)
IFM
FLA
COMBUSTION
FAN MOTOR
POWER SUPPLY
MINIMUM UNIT
DISCONNECT SIZE*
Min
Max
Qty
RLA
LRA
Qty
FLA
FLA
MCA
MOCP†
FLA
LRA
036
(3 Ton)
208/230-3-60
STD
NO
187
254
1
10.2
75
1
1.4
3.5
0.6
17.7
25
17
85
YES
23.7
25
23
90
ALT
NO
4.9
19.1
25
19
90
YES
25.1
30
25
95
HIGH
NO
5.2
19.4
25
19
109
YES
25.4
30
25
114
460-3-60
STD
NO
414
508
1
4.4
40
1
0.8
1.3
0.3
7.6
15
7
44
YES
10.3
15
10
47
ALT
NO
2.1
8.4
15
8
48
YES
11.1
15
11
50
HIGH
NO
2.6
8.9
15
9
57
YES
11.6
15
11
59
575-3-60
ALT
NO
518
632
1
3.7
31
1
0.6
1.9
0.3
7.1
15
7
37
YES
9.3
15
9
39
HIGH
NO
2.0
7.2
15
8
44
YES
9.4
15
10
45
048
(4 Ton)
208/230-3-60
STD
NO
187
254
1
15.4
90
1
1.4
3.5
0.6
24.2
30
23
101
YES
30.2
35
29
106
ALT
NO
4.9
25.6
30
25
105
YES
31.6
35
30
110
HIGH
NO
5.2
25.9
30
25
124
YES
31.9
35
31
129
460-3-60
STD
NO
414
508
1
8.3
45
1
0.8
1.8
0.3
13.0
20
13
51
YES
15.7
20
15
53
ALT
NO
2.1
13.3
20
13
53
YES
16.0
20
15
55
HIGH
NO
2.6
13.8
20
13
62
YES
16.5
20
16
64
575-3-60
ALT
NO
518
632
1
6.4
36
1
0.6
1.9
0.3
10.5
15
10
42
YES
12.7
15
12
43
HIGH
NO
2.0
10.6
15
10
49
YES
12.8
15
12
50
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
POWER EXHAUST
PART NO.
APPLICATION
USAGE
MCA
(230 V)
MCA
(460 V)
MCA
(575 V)
MOCP
(separate
power source
only)
CRPWREXH030A01
036-073*
1.6
N/A 0.64
15
CRPWREXH021A01
036-073
N/A 0.68
N/A
15
CRPWREXH022A01
090-151*
3.4
N/A 1.32
15
CRPWREXH023A01
090-151
N/A 1.4
N/A
15
CRPWREXH028A01
ALL*
1.7
N/A 0.68
15
CRPWREXH029A01
ALL
N/A 0.7
N/A
15
58
0
F
03
6-
15
1