Carrier 48AJ Heating System User Manual


 
37
Table 7 — Electrical Data — 48AJ,AK,AW,AY Units (cont)
LEGEND
*Fuse or HACR circuit breaker per NEC.
NOTES:
1. In compliance with NEC requirements for multimotor and combi-
nation load equipment (refer to NEC Articles 430 and 440), the
overcurrent protective device for the unit shall be fuse or HACR
breaker. The Canadian units may be fuse or circuit breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply volt-
age is greater than 2%. Use the following formula to determine
the percent of voltage imbalance.
% Voltage imbalance
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
= 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
= 1.53%
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
UNIT SIZE
48AJ,AK,
AW,AY
NOMINAL
VOLTAGE
(3 PH, 60 Hz)
VOLTAGE RANGE
COMPRESSOR
OFM IFM
POWER
EXHAUST
POWER
SUPPLY
No. 1 No. 2
Min Max RLA LRA RLA LRA Qty FLA Hp FLA
FLA
(total)
MCA MOCP*
035
208/230 187 253 57.1 266 57.1 266 4
5.3
(ea)
10 30.8/28.0
180.5/177.7 225/225
23.6/23.6 204.1/201.3 250/250
15 46.2/42.0
195.9/191.7 250/225
23.6/23.6 219.5/215.3 250/250
20 59.4/54.0
209.7/203.7 250/250
23.6/23.6 233.3/227.3 250/250
460 414 508 25.6 120 25.6 120 4
2.7
(ea)
10 14
82.4 100
12.6 95.0 110
15 21
89.4 110
12.6 102.0 125
20 27
95.8 110
12.6 108.4 125
575 518 632 20.5 96 20.5 96 4
2.4
(ea)
10 11
66.7 80
12.6 79.3 90
15 17
72.7 90
12.6 85.3 100
20 22
78.1 100
12.6 90.7 110
040
208/230 187 253 57.1 266 69.2 345 4
5.3
(ea)
15 46.2/42.0
211.0/206.8 250/250
23.6/23.6 234.6/230.4 300/250
20 59.4/54.0
224.2/218.8 250/250
23.6/23.6 247.8/242.4 300/300
25 74.8/68.0
241.0/232.8 300/300
23.6/23.6 264.6/256.4 300/300
460 414 508 25.6 120 28.8 173 4
2.7
(ea)
15 21
93.4 110
12.6 106.0 125
20 27
99.4 125
12.6 112.0 125
25 34
107.7 125
12.6 120.3 150
575 518 632 20.5 96 26.7 120 4
2.4
(ea)
15 17
80.5 100
12.6 93.1 110
20 22
85.5 110
12.6 98.1 110
25 27
90.6 110
12.6 103.2 125
FLA Full Load Amps
HACR— Heating, Air Conditioning and Refrigeration
IFM Indoor (Evaporator) Fan Motor
LRA Locked Rotor Amps
MCA Minimum Circuit Amps
MOCP— Maximum Overcurrent Protection
NEC National Electrical Code
OFM Outdoor (Condenser) Fan Motor
RLA Rated Load Amps
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
452 + 464 + 455
3
=
1371
3
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
7
457