19
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 under the control box. At-
tach power wires to the power connections on the main power ter-
minal block in the unit control box. Be sure to install a ground
wire.
CONTROL WIRING
All units require an accessory thermostat package to complete the
unit control system. For a room-mounted thermostat, the thermo-
stat may be mounted in an appropriate location in the conditioned
space. Route the wires from the thermostat to the low voltage con-
nection of the control box. Connect wires to the low voltage termi-
nal block. See Fig. 18. The fan switch on the thermostat will con-
trol fan operations.
FREEZE PROTECTION THERMOSTAT
A standard freeze protection thermostat is factory-installed.
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 (full load amps).
3. Motors are protected against primary single phasing condition.
4. Indoor-fan motors are 3-phase motors of same voltage as unit.
IMPORTANT: If supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
7
457
Table 2 — Electrical Data
UNIT
50XCW
V-PH-Hz
VOLTAGE
RANGE
COMPRESSOR
NO. 1
COMPRESSOR
NO. 2
Min
Max
RLA
LRA
RLA
LRA
06
208/230-3-60
187
253
18.3
136
—
—
460-3-60
414
506
8.8
66
—
—
575-3-60
518
632
6.6
55
—
—
08
208/230-3-60
187
253
23.0
149
—
—
460-3-60
414
506
11.0
75
—
—
575-3-60
518
632
8.0
54
—
—
12
208/230-3-60
187
253
15.6
110
15.9
110
460-3-60
414
506
7.8
52
7.1
52
575-3-60
518
632
5.8
39
5.1
39
14
208/230-3-60
187
253
19.6
136
19.2
136
460-3-60
414
506
8.2
66
8.7
66
575-3-60
518
632
6.6
55
6.9
55
16
208/230-3-60
187
253
28.7
191
23.0
149
460-3-60
414
506
13.3
100
11.0
75
575-3-60
518
632
10.0
78
8.0
54
24
208/230-3-60
187
253
40.7
240
28.7
191
460-3-60
414
506
19.3
140
13.3
100
575-3-60
518
632
15.6
107
10.0
78
LRA
—
Locked Rotor Amps
NEC
—
National Electrical Code
RLA
—
Rated Load Amps
