Table 38 – mca/mocp determination w/ pwrd c.o – Bryant LEGACY 558J User Manual
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Table 38 – MCA/MOCP DETERMINATION W/ PWRD C.O.
UN
IT
V
---
P
H
---
H
Z
IFM
TYPE
ELECTRIC HEATER
w/ PWRD 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
6
208/
230
---
3
---
60
STD
---
---
35.3
50
35
162
37.2
50
37
164
4.9/6.5
13.6/15.6
35.3/35.3
50/50
35/35
162/162
37.2/37.2
50/50
37/37
164/164
7.9/10.5
21.9/25.3
39.9/44.1
50/50
37/41
162/162
42.3/46.5
50/50
39/43
164/164
12.0/16.0
33.4/38.5
54.3/60.6
60/70
50/56
162/162
56.6/63.0
60/70
52/58
164/164
15.8/21.0
43.8/50.5
67.3/75.6
70/80
62/70
162/162
69.6/78.0
70/80
64/72
164/164
19.9/26.5
55.2/63.8
81.5/92.3
90/100
75/85
162/162
83.9/94.6
90/100
77/87
164/164
MED
---
---
37.6
50
38
188
39.5
50
40
190
4.9/6.5
13.6/15.6
37.6/37.6
50/50
38/38
188/188
39.5/39.5
50/50
40/40
190/190
7.9/10.5
21.9/25.3
42.8/47.0
50/50
39/43
188/188
45.1/49.4
50/50
42/45
190/190
12.0/16.0
33.4/38.5
57.1/63.5
60/70
53/58
188/188
59.5/65.9
60/70
55/61
190/190
15.8/21.0
43.8/50.5
70.1/78.5
80/80
65/72
188/188
72.5/80.9
80/90
67/74
190/190
19.9/26.5
55.2/63.8
84.4/95.1
90/100
78/88
188/188
86.8/97.5
90/100
80/90
190/190
HIGH
---
---
37.6
50
38
188
39.5
50
40
190
4.9/6.5
13.6/15.6
37.6/37.6
50/50
38/38
188/188
39.5/39.5
50/50
40/40
190/190
7.9/10.5
21.9/25.3
42.8/47.0
50/50
39/43
188/188
45.1/49.4
50/50
42/45
190/190
12.0/16.0
33.4/38.5
57.1/63.5
60/70
53/58
188/188
59.5/65.9
60/70
55/61
190/190
15.8/21.0
43.8/50.5
70.1/78.5
80/80
65/72
188/188
72.5/80.9
80/90
67/74
190/190
19.9/26.5
55.2/63.8
84.4/95.1
90/100
78/88
188/188
86.8/97.5
90/100
80/90
190/190
46
0
---
3
---
60
STD
---
---
17.7
25
18
81
18.7
25
19
82
6.0
7.2
17.7
25
18
81
18.7
25
19
82
11.5
13.8
23.3
25
21
81
24.5
25
23
82
14.0
16.8
27.0
30
25
81
28.3
30
26
82
23.0
27.7
40.6
45
37
81
41.9
45
39
82
25.5
30.7
44.4
45
41
81
45.6
50
42
82
MED
---
---
18.5
25
19
94
19.5
25
20
95
6.0
7.2
18.5
25
19
94
19.5
25
20
95
11.5
13.8
24.3
25
22
94
25.5
30
23
95
14.0
16.8
28.0
30
26
94
29.3
30
27
95
23.0
27.7
41.6
45
38
94
42.9
45
39
95
25.5
30.7
45.4
50
42
94
46.6
50
43
95
HIGH
---
---
19.5
25
20
103
20.5
30
21
104
6.0
7.2
19.5
25
20
103
20.5
30
21
104
11.5
13.8
25.5
30
23
103
26.8
30
25
104
14.0
16.8
29.3
30
27
103
30.5
35
28
104
23.0
27.7
42.9
45
39
103
44.1
45
41
104
25.5
30.7
46.6
50
43
103
47.9
50
44
104
57
5
---
3
---
60
STD
---
---
13.6
20
13
65
15.5
20
16
67
MED
---
---
14.4
20
14
76
16.3
20
17
78
HIGH
---
---
14.4
20
14
76
16.3
20
17
78
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