Bryant LEGACY 580J User Manual
Page 43
43
Table 28 -- MCA/MOCP DETERMINATION NO C.O. OR UNPWRD C.O. (con’t)
UN
IT
NOM.
V---Ph---Hz
IFM
TYPE
COMBUSTION
FAN MOTOR
FLA
POWER
EXHAUST
FLA
NO C.O. or UNPWR C.O.
NO P.E.
w/ P.E. (pwrd fr/ unit)
MCA
MOCP
DISC. SIZE
MCA
MOCP
DISC. SIZE
FLA
LRA
FLA
LRA
580J
*28D
208/230---3---60
STD
0.52
5.9
129.2
175
135
584
141.0
175
148
604
MED
127.0
175
132
586
138.8
175
146
606
HIGH
133.6
175
140
622
145.4
175
153
642
MED---
High Eff
134.6
175
141
594
146.4
175
155
614
HIGH---
High Eff
147.3
175
156
668
159.1
200
169
688
460---3---60
STD
0.3
3.1
52.9
60
55
299
59.1
70
63
311
MED
51.9
60
54
300
58.1
70
61
312
HIGH
55.2
60
58
318
61.4
70
65
330
MED---
High Eff
55.7
70
59
304
61.9
80
66
316
HIGH---
High Eff
61.7
80
66
341
67.9
80
73
353
575---3---60
STD
0.24
2.4
41.1
50
43
244
45.9
60
49
252
MED
40.6
50
42
233
45.4
60
48
241
HIGH
43.3
50
46
259
48.1
60
51
267
MED---
High Eff
44.5
50
47
242
49.3
60
52
250
HIGH---
High Eff
45.0
50
47
269
49.8
60
53
277
LEGEND:
C.O.
--- Convenient outlet
DISC
--- Disconnect
FLA
--- Full load amps
IFM
--- Indoor fan motor
LRA
--- Locked rotor amps
MCA
--- Minimum circuit amps
MOCP
--- Maximum over current protection
P.E.
--- Power exhaust
UNPWRD 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 break-
er.
2.
Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply volt-
age is greater than 2%. Use the following formula to determine
the percentage of voltage imbalance.
% Voltage Imbalance
= 100 x
max voltage deviation from average voltage
average voltage
Example: Supply voltage is 230-3-60
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage =
(224 + 231 + 226)
=
681
3
3
=
227
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
= 100 x
4
227
= 1.76%
This amount of phase imbalance is satisfactory as it is below the maxi-
mum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.
580J