Bryant LEGACY 558J Product Data page 42

Table 38 – 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
--- 35.3 50
13.6/15.6 35.3/35.3 50/50
21.9/25.3 39.9/44.1 50/50
33.4/38.5 54.3/60.6 60/70
43.8/50.5 67.3/75.6 70/80
55.2/63.8 81.5/92.3 90/100
--- 37.6 50
13.6/15.6 37.6/37.6 50/50
21.9/25.3 42.8/47.0 50/50
33.4/38.5 57.1/63.5 60/70
43.8/50.5 70.1/78.5 80/80
55.2/63.8 84.4/95.1 90/100
--- 37.6 50
13.6/15.6 37.6/37.6 50/50
21.9/25.3 42.8/47.0 50/50
33.4/38.5 57.1/63.5 60/70
43.8/50.5 70.1/78.5 80/80
55.2/63.8 84.4/95.1 90/100
--- 17.7 25
7.2 17.7 25
13.8 23.3 25
16.8 27.0 30
27.7 40.6 45
30.7 44.4 45
--- 18.5 25
7.2 18.5 25
13.8 24.3 25
16.8 28.0 30
27.7 41.6 45
30.7 45.4 50
--- 19.5 25
7.2 19.5 25
13.8 25.5 30
16.8 29.3 30
27.7 42.9 45
30.7 46.6 50
--- 13.6 20
--- 14.4 20
--- 14.4 20
average voltage
w/ PWRD C.O.
NO P .E.
DISC. SIZE
FLA LRA
35 162
35/35 162/162
37/41 162/162
50/56 162/162
62/70 162/162
75/85 162/162
38 188
38/38 188/188
39/43 188/188
53/58 188/188
65/72 188/188
78/88 188/188
38 188
38/38 188/188
39/43 188/188
53/58 188/188
65/72 188/188
78/88 188/188
18 81
18 81
21 81
25 81
37 81
41 81
19 94
19 94
22 94
26 94
38 94
42 94
20 103
20 103
23 103
27 103
39 103
43 103
13 65
14 76
14 76
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.
42
w/ P .E. (pwrd fr/unit)
DISC. SIZE
MCA MOCP
FLA
37.2 50 37
37.2/37.2 50/50 37/37
42.3/46.5 50/50 39/43
56.6/63.0 60/70 52/58
69.6/78.0 70/80 64/72
83.9/94.6 90/100 77/87
39.5 50 40
39.5/39.5 50/50 40/40
45.1/49.4 50/50 42/45
59.5/65.9 60/70 55/61
72.5/80.9 80/90 67/74
86.8/97.5 90/100 80/90
39.5 50 40
39.5/39.5 50/50 40/40
45.1/49.4 50/50 42/45
59.5/65.9 60/70 55/61
72.5/80.9 80/90 67/74
86.8/97.5 90/100 80/90
18.7 25 19
18.7 25 19
24.5 25 23
28.3 30 26
41.9 45 39
45.6 50 42
19.5 25 20
19.5 25 20
25.5 30 23
29.3 30 27
42.9 45 39
46.6 50 43
20.5 30 21
20.5 30 21
26.8 30 25
30.5 35 28
44.1 45 41
47.9 50 44
15.5 20 16
16.3 20 17
16.3 20 17
(224 + 231 + 226)
=
3
227
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
4
= 100 x
227
= 1.76%
LRA
164
164/164
164/164
164/164
164/164
164/164
190
190/190
190/190
190/190
190/190
190/190
190
190/190
190/190
190/190
190/190
190/190
82
82
82
82
82
82
95
95
95
95
95
95
104
104
104
104
104
104
67
78
78
681
3