548 f – Bryant 549B User Manual
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64
ELECTRICAL DATA — 548F (cont)
548F036-120 (UNITS WITH ELECTRICAL CONVENIENCE OUTLET) (cont)
LEGEND
*Heaters are field installed only.
†Used to determine minimum disconnect size per NEC.
**Heater capacity (kW) is based on heater voltage of 208 v, 240 v, 480 v, and 575 v. If power
distribution voltage to unit varies from rated heater voltage, heater kW will vary accordingly.
††Fuse or HACR circuit breaker.
***Optional disconnect switch is unavailable.
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.
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.
% 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.
POWER EXHAUST ELECTRICAL DATA
N/A — Not available
NOTE: 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. 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 548F060 unit with MCA = 35.6 and MOCP = 40, with
CRPWREXH030A01 power exhaust.
MCA New = 35.6 amps + 1.6 amps = 37.2 amps
If the new MCA does not exceed the published MOCP, then MOCP would not change. The
MOCP in this example is 40 amps and the MCA New is below 40; therefore the MOCP is
acceptable. If “MCA New” is larger than the published MOCP, raise the MOCP to the next larger
size. In all cases, the MOCP for the power exhaust should be 15 amps per NEC.
UNIT
548F
NOMINAL
V-PH-Hz
IFM
TYPE
VOLTAGE
RANGE
COMPRESSOR
(each)
OFM
FLA
IFM
FLA
ELECTRIC
HEAT*
POWER SUPPLY
DISCONNECT
SIZE†
Min
Max
RLA
LRA
Nominal
kW**
FLA
MCA
MOCP
FLA
LRA
120
(10 Tons)
460-3-60
STD
414
508
8.6
59.6
0.7
2.6
—
—
25.5
30††
27
145
16.5
19.8
50.3
60††
50
165
27.8
33.4
67.3
70
65
178
33.0
39.7
75.2
80
73
185
41.7
50.2
88.3
90
85
195***
50.0
60.1
85.6
90
96
205***
ALT
414
508
8.6
59.6
0.7
3.4
—
—
26.3
30††
28
185
16.5
19.8
51.1
60††
51
204
27.8
33.4
68.1
70
66
218
33.0
39.7
76.0
80
73
224
41.7
50.2
89.1
90
86
235***
50.0
60.1
86.4
90
97
245***
HIGH-STATIC
414
508
8.6
59.6
0.7
7.4
—
—
30.3
35††
32
179
16.5
19.8
55.1
60††
55
198
27.8
33.4
72.1
80
71
212
33.0
39.7
80.0
80
78
218
41.7
50.2
93.1
100
90
229***
50.0
60.1
90.4
100
102
239***
575-3-60
STD
518
632
6.9
49.4
0.7
2.6
—
—
20.5
25††
22
120
17.0
17.1
41.8
45††
41
137
34.0
34.1
63.1
70
61
154
51.0
51.2
71.7
80
80
171***
ALT
518
632
6.9
49.4
0.7
3.4
—
—
21.1
25††
22
151
17.0
17.1
42.5
45††
42
168
34.0
34.1
63.7
70
62
185
51.0
51.2
72.3
80
81
202***
HIGH-STATIC
518
632
6.9
49.4
0.7
7.4
—
—
24.3
25††
26
146
17.0
17.1
45.7
50††
46
163
34.0
34.1
66.9
70
65
180
51.0
51.2
75.5
80
85
198***
FLA
— Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
IFM
— Indoor Fan Motor
LRA
— Locked Rotor Amps
MCA
— Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC
— National Electrical Code
OFM
— Outdoor Fan Motor
RLA
— Rated Load Amps
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
452 + 464 + 455
3
=
1371
3
POWER EXHAUST
PART NO.
MCA
(230 v)
MCA
(460 v)
MCA
(575 v)
MOCP
(for separate
power source)
CRPWREXH021A01
N/A
0.68
N/A
15
CRPWREXH022A01
3.4
N/A
1.32
15
CRPWREXH023A01
N/A
1.4
N/A
15
CRPWREXH028A01
1.7
N/A
0.68
15
CRPWREXH029A01
N/A
0.7
N/A
15
CRPWREXH030A01
1.6
N/A
0.64
15
7
457
548
F