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NOM.
IFM
V ---Ph---Hz
TYPE
STD
208/230---3---60
MED
HIGH
STD
MED
460--- 3--- 60
HIGH
STD
575--- 3--- 60
MED
HIGH
NOM.
IFM
V ---Ph---Hz
TYPE
STD
MED
208/230---3---60
HIGH
STD
460--- 3--- 60
MED
HIGH
STD
MED
575--- 3--- 60
HIGH
Legend and Notes for Table 10
LEGEND:
BRKR
--- Circuit breaker
CO
--- Convenience outlet
DISC
--- Disconnect
FLA
--- Full load amps
IFM
--- Indoor fan motor
LRA
--- Locked rotor amps
MCA
--- Minimum circuit amps
P .E.
--- Power exhaust
PWRD CO
--- Powered convenient outlet
UNPWR CO
--- Unpowered convenient outlet
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 de-
termine the percentage of voltage imbalance.
max voltage deviation from average voltage
% Voltage Imbalance
= 100 x
Table 10 – Unit Wire/Fuse or HACR Breaker Sizing Data
COMBUSTION
POWER
FAN MOTOR
EXHAUST
FLA
FLA
0.48
3.8
0.25
1.8
0.24
3.8
Table 10 — Unit Wire/Fuse or HACR Breaker Sizing Data (cont)
COMBUSTION
POWER
FAN MOTOR
EXHAUST
FLA
FLA
0.48
3.8
0.25
1.8
0.24
3.8
average voltage
NO C.O. or UNPWR C.O.
NO P .E.
FUSE
DISC. SIZE
or
MCA
HACR
FLA
LRA
BRKR
68.3
80
71
396
70.8
80
74
413
81.2
100
86
432
34
45
35
234
35.0
45
37
243
40.8
50
43
252
26.5
30
28
184
26.5
30
28
184
32.7
40
35
196
w/ PWRD C.O.
NO P .E.
FUSE
DISC. SIZE
or
MCA
HACR
FLA
LRA
BRKR
73.1
80
77
401
75.6
100
80
418
86.0
100
92
437
36.2
45
38
236
37.2
50
39
245
43.0
50
46
254
28.2
35
30
186
28.2
35
30
186
34.4
40
37
198
Example: Supply voltage is 230-3-60
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage =
=
Determine maximum deviation from average voltage.
(AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v
(AC) 227 – 226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% 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 your local electric utility company immediately.
45
w/ P .E. (pwrd fr/ unit)
FUSE
DISC. SIZE
or
MCA
HACR
FLA
BRKR
72.1
80
76
74.6
90
79
85.0
100
91
35.8
45
37
36.8
45
39
42.6
50
45
30.3
40
32
30.3
40
32
36.5
45
39
w/ P .E. (pwrd fr/ unit)
FUSE
DISC. SIZE
or
MCA
HACR
FLA
BRKR
76.9
100
81
79.4
100
84
89.8
100
96
38
50
40
39.0
50
41
44.8
50
48
32
40
34
32
40
34
38.2
45
41
(224 + 231 + 226)
=
3
227
4
= 100 x
227
= 1.76%
LRA
400
417
436
236
245
254
188
188
200
LRA
405
422
441
238
247
256
190
190
202
681
3
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