13
Table 4 — Electrical Data (Units Without Optional Convenience Outlet) (cont)
UNIT
SIZE
50PG
NOMINAL
VOLTAGE
(3 Ph,
60 Hz)
VOLTAGE
RANGE
COMPRESSOR
OFM
ELECTRIC
HEAT
IFM
POWER
EXHAUST
POWER SUPPLY
POWER SUPPLY
WITH OPTIONAL
HACR BREAKER
DISCONNECT
SIZE
No. 1 No. 2 No. 3
Min Max RLA LRA RLA LRA RLA LRA Qty Hp
FLA
(ea)
kW FLA Hp FLA Qty Hp
FLA
(ea)
MCA MOCP* MCA MOCP FLA
20
575 518 633 12.8 83 12.8 83 — — 4 0.25 0.7
— —
5 6.1
— — — 38 50 38 50 40
2 1 2.4 43 50 43 50 45
7.5 9
— — — 41 50 41 50 43
2 1 2.4 45 50 45 50 49
10 11
— — — 43 50 43 50 45
2 1 2.4 47 60 47 60 51
24.8 24
5 6.1
— — — 38 50 38 50 40
2 1 2.4 44 50 44 50 45
7.5 9
— — — 41 50 41 50 43
2 1 2.4 47 50 47 50 49
10 11
— — — 44 50 44 50 45
2 1 2.4 50 60 50 60 51
48.3 46
5 6.1
— — — 65 70 65 70 60
2 1 2.4 71 80 71 80 65
7.5 9
— — — 69 70 69 70 63
2 1 2.4 75 80 75 80 69
10 11
— — — 71 80 71 80 66
2 1 2.4 77 80 77 80 71
78 75
5 6.1
— — — 83 90 83 90 93
2 1 2.4 89 100 89 100 99
7.5 9
— — — 86 100 86 100 97
2 1 2.4 92 100 92 100 102
10 11
— — — 89 100 89 100 99
2 1 2.4 95 100 95 100 104
Electric Heat Branch Circuit For 208/240-V 75-kW Electric Heat{
UNIT
SIZE
50PG
NOMINAL
VOLTAGE
(3 Ph,
60 Hz)
VOLTAGE
RANGE
COMPRESSOR
OFM
ELECTRIC
HEAT
IFM
POWER
EXHAUST
POWER SUPPLY
POWER SUPPLY
WITH OPTIONAL
HACR BREAKER
DISCONNECT
SIZE
No. 1 No. 2 No. 3
Min Max RLA LRA RLA LRA RLA LRA Qty Hp
FLA
(ea)
kW FLA Hp FLA Qty Hp
FLA
(ea)
MCA MOCP* MCA MOCP FLA
20
208/240 187 253 NA NA NA NA NA NA NA NA NA 56/75 156/180 NA NA NA NA NA 156/180 175/200 180/180 200/200 179/207
Feeder Circuit For 208/230-V Unit With 75-kW Electric Heat{
UNIT
SIZE
50PG
NOMINAL
VOLTAGE
(3 Ph,
60 Hz)
VOLTAGE
RANGE
COMPRESSOR
OFM
ELECTRIC
HEAT
IFM
POWER
EXHAUST
POWER SUPPLY
POWER SUPPLY
WITH OPTIONAL
HACR BREAKER
DISCONNECT
SIZE
No. 1 No. 2 No. 3
Min Max RLA LRA RLA LRA RLA LRA Qty Hp
FLA
(ea)
kW FLA Hp FLA Qty Hp
FLA
(ea)
MCA MOCP* MCA MOCP FLA
20
208/240 187 253 28.2 208 28.2 208 — — 4 0.25 1.5 56/75 156/180
3.7 10.6/9.6
— — — 169/192 200/225 192/192 200/225 192/218
2 1 5.9 184/207 200/225 207/207 225/225 205/232
5 16.7/15.2
— — — 177/199 200/225 199/199 200/225 199/224
2 1 5.9 192/214 200/225 214/214 225/225 212/238
7.5 24.2/22
— — — 186/208 200/225 208/208 225/225 207/232
2 1 5.9 201/222 225/225 222/222 225/225 221/246
10 30.8/28
— — — 195/215 225/225 215/215 225/225 215/239
2 1 5.9 209/230 225/250 230/230 250/250 228/253
LEGEND
FLA --- F u l l L o a d A m p s
HACR --- Heating, Air Conditioning and Refrigeration
IFM --- Indoor (Evaporator) Fan Motor
LRA --- L o c k e d R o t o r A m p s
MCA --- Minimum Circuit Amps
MOCP --- Maximum Overcurrent Protection
NEC --- National Electrical Code
OFM --- Outdoor (Condenser) Fan Motor
RLA --- RatedLoadAmps
* Fuse or HACR circuit breaker.
{ 208/230 v 75---kW Electric Heat units must use dual--- point wiring. The main table lists the
branch circuit values for the refrigeration part of the system. The following two tables list the
branch circuit values for the electric heat and values for a feeder circuit for both branch
circuits.
NOTES:
1. In compliance with NEC requirements for multimotor and combination load equip-
ment (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 460-3-60
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =
452 + 464 + 455
3
1371
3
=
457
=
Determine maximum deviation from average voltage.
(AB) 457 – 452 = 5 v
(BC) 464 – 457 = 7 v
(AC) 457 – 455 = 2 v
Maximum deviation is 7 v.
Determine percent of voltage imbalance.
% Voltage Imbalance = 100 x
7
457
= 1.53%
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%, contact your local electric
utility company immediately.
3. The 75-kW 208/240-v electric heat can be factory installed but it must be wired
separately in the field.
4. The convenience outlet full load amps (FLA) are 5, 3 and 3 for 208/230, 460, 575-v
units, respectively.
5. The FLA load amps provided in the table for electric heaters are based on 208/240,
480 and 600 v.
6. MCA calculation for 50PG units with electric heaters over 50 kW is = 1.25 x (IFM +
P ower Exhaust + Convenience Outlet FLA amps) + 1.00 x (Electric Heater FLA).
50PG20 ---28
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