42
Table 38 – MCA/MOCP DETERMINATION W/ PWRD C.O.
UNIT
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*06
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
4 6 0 --- 3 --- 6 0
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
5 7 5 --- 3 --- 6 0
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
P E --- Po w e r e x h a u st
UNPWRD CO --- Unpowered convenient outlet
NOTES:
1. In compliance with NEC requirements for mu ltimotor and combina-
tion l oa d 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 de viation from average voltage
average voltage
Example: Su pply 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 vol tage phase imbalance is more than 2%, con-
tact your local electric utility company immediately.
558J
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