Example:
A 7 ½ Ton unit is to be installed. The distance from the building to the unit is 75’. Calculate the minimum wire size assuming no more than 2% voltage drop.
MCA for 7 ½ Ton 230V unit = 43.3 (from S&R plate).
Applying previous table wire sizes less than #8 AWG cannot be used for circuits which have a rating of 45A. The #8 wire is not suitable since the maximum length for a 45A circuit is 68’.
Solution: Use a #6 AWG wire suitable up to 110’.
NOTE: It is the contractors’s responsibility to follow the NEC (USA) or CEC (Canada) when sizing the service wire for this unit.
Local codes often require a disconnect switch located near the unit; do not install the switch on the unit. Refer to the installa- tion instructions supplied with the indoor furnace/air handler for specific wiring connections and indoor unit configuration. Like- wise, consult the instructions packaged with the thermostat for mounting and location information.
Overcurrent Protection
The following overcurrent protection devices are approved for use.
•Time delay fuses
•HACR type circuit breakers
These devices have sufficient time delay to permit the motor- compressor to start and accelerate its load.
Refer to the unit serial plate and this table for the maximum overcurrent protection permitted.
Run all line voltage wiring a conduit from the service discon- nect box to the unit. Refer to the NEC (USA) or CEC (Canada) codes for the correct size conduit based on the wire size. The conduit enters the control box through the hole provided in the bottom. NOTE: The control box hole is sized for 3/4” conduit. If permitted by code, a flexible conduit is preferred to minimize vibration transmission from the unit to the building.
Connect the line voltage wires to the L1, L2, and L3 terminals of the definite purpose contactor (located in the unit control box). Refer to the wiring diagram attached to the unit when making these connections.
To correct, disconnect power and switch any two leads at the unit contactor and
High Voltage Connections
Route power supply and ground wires through the high voltage port and terminate in accordance with the wiring diagram pro- vided inside the control panel cover.
Low Voltage Connections
Condensing unit control wiring requires a
SINGLE STATE LOW VOLTAGE
THERMOSTAT | |||
Y1 | W1 | R | G |
|
|
| AIR |
|
|
| HANDLER |
|
|
| AH090/120 |
CONDENSING |
|
| GREEN |
UNIT |
|
|
|
CKL090/120 |
|
| RED |
|
|
| |
YELLOW |
|
|
|
BLACK |
|
| WHITE |
BLUE |
|
| BLUE |
NOTES:
1). THERMOSTAT TO AIR HANDLER CABLE MUST HAVE A MINIMUM OF (4) CONDUCTORS
|
|
|
|
2). AIR HANDLER TO CONDENSING UNIT CABLE | WIRE NUT | ||
MUST HAVE A MINIMUM OF (2) CONDUCTORS |
|
|
|
System Start Up
Never operate the compressor with the suction valve closed to test the compressor’s pumping efficiency. In some cases, this can result in serious compressor damage and loss of warranty coverage.
NOTICE
THIS UNIT IS SHIPPED WITH A NITROGEN/HELIUM HOLDING CHARGE ONLY. UNIT MUST BE EVACUATED AND CHARGED PER INSTALLATION INSTRUCTIONS WITH REFRIGERANT LISTED ON SERIAL RATING PLATE.
Three Phase Compressor Rotation
CAUTION
Use care when handling scroll compressors. Dome temp- eratures could be hot.
Three phase scrolls are power phase dependent and can com- press in more than one direction.
Verify proper rotation for three phase compressors by ensuring the suction pressure drops and discharge pressure rises when the compressor is energized. NOTE: When operated in re- verse, a three phase scroll compressors is noisier and its cur- rent draw substantially reduced compared to marked values.
NOTICE
UNITS SHIPPED WITH A HOLDING CHARGE ARE INTENDED FOR COMPONENT REPLACEMENT ONLY ON EXISTING SYSTEMS, AND NOT INTENDED FOR USE IN NEW SYSTEMS OR NEWLY CONSTRUCTED HOMES.
NOTICE
UNITS MUST ONLY BE USED AS REPLACEMENT COMPONENTS FOR
6
