Bryant LEGACY 558J Product Data page 39

Table 35 – MCA/MOCP DETERMINATION W/ PWRD C.O.
ELECTRIC HEATER
IFM
TYPE
kW
---
4.9/6.5
7.9/10.5
STD
12.0/16.0
15.8/21.0
19.9/26.5
---
4.9/6.5
7.9/10.5
MED
12.0/16.0
15.8/21.0
19.9/26.5
---
4.9/6.5
7.9/10.5
HIGH
12.0/16.0
15.8/21.0
19.9/26.5
---
6.0
11.5
STD
14.0
23.0
25.5
---
6.0
11.5
MED
14.0
23.0
25.5
---
6.0
11.5
HIGH
14.0
23.0
25.5
STD ---
MED ---
HIGH ---
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.
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
FLA
MCA MOCP
--- 30.5 45
13.6/15.6 30.5/30.5 45/45
21.9/25.3 33.9/38.1 45/45
33.4/38.5 48.3/54.6 50/60
43.8/50.5 61.3/69.6 70/70
55.2/63.8 75.5/86.3 80/90
--- 32.8 50
13.6/15.6 32.8/32.8 50/50
21.9/25.3 36.8/41.0 50/50
33.4/38.5 51.1/57.5 60/60
43.8/50.5 64.1/72.5 70/80
55.2/63.8 78.4/89.1 80/90
--- 32.8 50
13.6/15.6 32.8/32.8 50/50
21.9/25.3 36.8/41.0 50/50
33.4/38.5 51.1/57.5 60/60
43.8/50.5 64.1/72.5 70/80
55.2/63.8 78.4/89.1 80/90
--- 15.5 25
7.2 15.5 25
13.8 20.5 25
16.8 24.3 25
27.7 37.9 40
30.7 41.6 45
--- 16.3 25
7.2 16.3 25
13.8 21.5 25
16.8 25.3 30
27.7 38.9 40
30.7 42.6 45
--- 17.3 25
7.2 17.3 25
13.8 22.8 25
16.8 26.5 30
27.7 40.1 45
30.7 43.9 45
--- 11.9 15
--- 12.7 20
--- 12.7 20
average voltage
NO C.O. or UNPWRD C.O.
NO P .E.
DISC. SIZE
FLA LRA
30 157
30/30 157/157 32.4/32.4
31/35 157/157 36.3/40.5
44/50 157/157 50.6/57.0
56/64 157/157 63.6/72.0
69/79 157/157 77.9/88.6
32 183
32/32 183/183 34.7/34.7
34/38 183/183 39.1/43.4
47/53 183/183 53.5/59.9
59/67 183/183 66.5/74.9
72/82 183/183 80.8/91.5
32 183
32/32 183/183 34.7/34.7
34/38 183/183 39.1/43.4
47/53 183/183 53.5/59.9
59/67 183/183 66.5/74.9
72/82 183/183 80.8/91.5
15 79
15 79
19 79
22 79
35 79
38 79
16 92
16 92
20 92
23 92
36 92
39 92
17 101
17 101
21 101
24 101
37 101
40 101
12 63
12 74
12 74
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
% 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%, con-
tact your local electric utility company immediately.
39
w/ P .E. (pwrd fr/unit)
DISC. SIZE
MCA MOCP
FLA
32.4 50 32
50/50 32/32
50/50 33/37
60/60 47/52
70/80 59/66
80/90 72/82
34.7 50 34
50/50 34/34
50/50 36/40
60/60 49/55
70/80 61/69
90/100 74/84
34.7 50 34
50/50 34/34
50/50 36/40
60/60 49/55
70/80 61/69
90/100 74/84
16.5 25 16
16.5 25 16
21.8 25 20
25.5 30 23
39.1 40 36
42.9 45 39
17.3 25 17
17.3 25 17
22.8 25 21
26.5 30 24
40.1 45 37
43.9 45 40
18.3 25 18
18.3 25 18
24.0 25 22
27.8 30 26
41.4 45 38
45.1 50 42
13.8 20 14
14.6 20 15
14.6 20 15
(224 + 231 + 226)
=
3
227
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
4
= 100 x
227
= 1.76%
LRA
159
159/159
159/159
159/159
159/159
159/159
185
185/185
185/185
185/185
185/185
185/185
185
185/185
185/185
185/185
185/185
185/185
80
80
80
80
80
80
93
93
93
93
93
93
102
102
102
102
102
102
65
76
76
681
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