Table 35 – mca/mocp determination w/ pwrd c.o – Bryant LEGACY 558J User Manual
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Table 35 – MCA/MOCP DETERMINATION W/ PWRD C.O.
UN
IT
V
---
P
H
---
H
Z
IFM
TYPE
ELECTRIC HEATER
NO C.O. or UNPWRD C.O.
kW
FLA
NO P.E.
w/ P.E. (pwrd fr/unit)
MCA
MOCP
DISC. SIZE
MCA
MOCP
DISC. SIZE
FLA
LRA
FLA
LRA
558J
*0
7
208/
230
---
3
---
60
STD
---
---
30.5
45
30
157
32.4
50
32
159
4.9/6.5
13.6/15.6
30.5/30.5
45/45
30/30
157/157
32.4/32.4
50/50
32/32
159/159
7.9/10.5
21.9/25.3
33.9/38.1
45/45
31/35
157/157
36.3/40.5
50/50
33/37
159/159
12.0/16.0
33.4/38.5
48.3/54.6
50/60
44/50
157/157
50.6/57.0
60/60
47/52
159/159
15.8/21.0
43.8/50.5
61.3/69.6
70/70
56/64
157/157
63.6/72.0
70/80
59/66
159/159
19.9/26.5
55.2/63.8
75.5/86.3
80/90
69/79
157/157
77.9/88.6
80/90
72/82
159/159
MED
---
---
32.8
50
32
183
34.7
50
34
185
4.9/6.5
13.6/15.6
32.8/32.8
50/50
32/32
183/183
34.7/34.7
50/50
34/34
185/185
7.9/10.5
21.9/25.3
36.8/41.0
50/50
34/38
183/183
39.1/43.4
50/50
36/40
185/185
12.0/16.0
33.4/38.5
51.1/57.5
60/60
47/53
183/183
53.5/59.9
60/60
49/55
185/185
15.8/21.0
43.8/50.5
64.1/72.5
70/80
59/67
183/183
66.5/74.9
70/80
61/69
185/185
19.9/26.5
55.2/63.8
78.4/89.1
80/90
72/82
183/183
80.8/91.5
90/100
74/84
185/185
HIGH
---
---
32.8
50
32
183
34.7
50
34
185
4.9/6.5
13.6/15.6
32.8/32.8
50/50
32/32
183/183
34.7/34.7
50/50
34/34
185/185
7.9/10.5
21.9/25.3
36.8/41.0
50/50
34/38
183/183
39.1/43.4
50/50
36/40
185/185
12.0/16.0
33.4/38.5
51.1/57.5
60/60
47/53
183/183
53.5/59.9
60/60
49/55
185/185
15.8/21.0
43.8/50.5
64.1/72.5
70/80
59/67
183/183
66.5/74.9
70/80
61/69
185/185
19.9/26.5
55.2/63.8
78.4/89.1
80/90
72/82
183/183
80.8/91.5
90/100
74/84
185/185
46
0
---
3
---
60
STD
---
---
15.5
25
15
79
16.5
25
16
80
6.0
7.2
15.5
25
15
79
16.5
25
16
80
11.5
13.8
20.5
25
19
79
21.8
25
20
80
14.0
16.8
24.3
25
22
79
25.5
30
23
80
23.0
27.7
37.9
40
35
79
39.1
40
36
80
25.5
30.7
41.6
45
38
79
42.9
45
39
80
MED
---
---
16.3
25
16
92
17.3
25
17
93
6.0
7.2
16.3
25
16
92
17.3
25
17
93
11.5
13.8
21.5
25
20
92
22.8
25
21
93
14.0
16.8
25.3
30
23
92
26.5
30
24
93
23.0
27.7
38.9
40
36
92
40.1
45
37
93
25.5
30.7
42.6
45
39
92
43.9
45
40
93
HIGH
---
---
17.3
25
17
101
18.3
25
18
102
6.0
7.2
17.3
25
17
101
18.3
25
18
102
11.5
13.8
22.8
25
21
101
24.0
25
22
102
14.0
16.8
26.5
30
24
101
27.8
30
26
102
23.0
27.7
40.1
45
37
101
41.4
45
38
102
25.5
30.7
43.9
45
40
101
45.1
50
42
102
57
5
---
3
---
60
STD
---
---
11.9
15
12
63
13.8
20
14
65
MED
---
---
12.7
20
12
74
14.6
20
15
76
HIGH
---
---
12.7
20
12
74
14.6
20
15
76
LEGEND:
CO
--- 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
PE
--- Power exhaust
UNPWRD CO
--- Unpowered convenient outlet
NOTES:
1. In compliance with NEC requirements for multimotor and combina-
tion 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
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
Maximum deviation is 4 v.
(BC) 231 – 227 = 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 maximum
allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%, con-
tact your local electric utility company immediately.
558J