7
Step 6 — Complete Electrical Connections
GENERAL
Verify that nameplate electrical requirements match available
power supply. Voltage at condenser must be within the minimum
and maximum shown in Table 4 and phases must be balanced
within 2%. Contact local power company for line voltage correc
-
tions. Never operate a motor where a phase imbalance in supply
voltage is greater than 2%.
UNBALANCED 3-PHASE SUPPLY VOLTAGE
Use the following formula to determine the percent of voltage im
-
balance.
Percent Voltage Imbalance
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
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 operation on improper line voltage or excessive phase imbal
-
ance may be considered abuse and any resulting damage may not
be covered by Carrier warranty.
All wiring must be in accordance with local or NEC (National
Electrical Code) regulations.
POWER WIRING
The units must have adequate overcurrent protection, fuses, or
HACR (Heating, Air-Conditioning and Refrigeration) breakers,
according to the national and applicable local codes.
For field power connections, all main power wiring enters the unit
through a factory-punched access hole on the right side of the unit.
See Fig. 1. Attach power wires to the power connections on the
main power terminal block in the unit control box. Be sure to in
-
stall a ground wire.
CONTROL WIRING
Connect 24-v control wires to the 2 low-voltage connections at the
compressor contactor. Use field-supplied wire nuts to make the
connections to the terminal strip in the control box. For field con
-
trol connections, all wiring enters the unit through a factory-
punched access hole on the right side of the unit. See Fig. 1.
Table 4 —
Fan Electrical Data
LEGEND
NOTES:
1. In compliance with NEC requirements for multimotor and combina-
tion load equipment (NEC Articles 430 and 440), the overcurrent
protective device for the unit shall be fuse or HACR circuit breaker.
Canadian units may be fuse or circuit breaker.
2. Wire sizing amps are a sum of 125% of the compressor RLA plus
100% of indoor fan motor FLA.
3. Motors are protected against primary single phasing condition.
4. Indoor-fan motors are 3-phase motors of same voltage as unit.
= 100 x max voltage deviation from average voltage
average voltage
Average Voltage = 452 + 464 + 455
3
= 1371
3
= 457
IMPORTANT: If supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
7
457
MOTOR
CODE
HP
V-PH-HZ
VOLTAGE
RANGE
FLA
MCA
MOPD
DISC
MIN
MAX
D
1.00
208/230-3-60
187
253
3.2/3.2
4.0/4.0
15/15
30
460-3-60
414
506
1.6
2.0
15
30
575-3-60
518
632
1.1
1.4
15
30
E
1.50
208/230-3-60
187
253
4.6/4.8
5.8/6.0
15/15
30
460-3-60
414
506
2.4
3.0
15
30
575-3-60
518
632
1.6
1.9
15
30
F
2.00
208/230-3-60
187
253
6.0/5.8
7.5/7.2
15/15
30
460-3-60
414
506
2.9
3.6
15
30
575-3-60
518
632
2.1
2.6
15
30
G
3.00
208/230-3-60
187
253
9.2/8.6
11.5/10.8
20/15
30
460-3-60
414
506
4.3
5.4
15
30
575-3-60
518
632
3.4
4.2
15
30
H
5.00
208/230-3-60
187
253
14.5/13.6
18.1/17.0
30/30
30
460-3-60
414
506
6.8
8.5
15
30
575-3-60
518
632
5.4
6.8
15
30
J
7.50
208/230-3-60
187
253
21.5/19.4
26.9/24.2
45/40
30
460-3-60
414
506
9.7
12.1
20
30
575-3-60
518
632
7.5
9.4
15
30
FLA
—
Full Load Amps
DISC
—
Disconnect
MCA
—
Minimum Circuit Amps
MOPD
—
Minimum Overcurrent Protection Device
NEC
—
National Electrical Code
RLA
—
Rated Load Amps
