Nordyne R-410A SYSTEM OPERATION Pre-StartChecklist, Start-UpProcedure, Defrost Test Procedure

SYSTEM OPERATION

Pre-Start Checklist

The following check list should be observed prior to starting the unit.

√Is the unit level? Unit should be level or slightly slanted toward the drain for proper condensate drainage.

√Is the unit installed with the proper clearances as listed in Figure 2 (page 5)?

√Is the wiring correct according to the wiring diagram and electrical codes?

√Are all the wiring connections tight? Check the condenser fan to make sure it turns freely.

√Is the overcurrent protection properly sized?

√Is the thermostat wired correctly? Is it installed in a proper location?

Start-Up Procedure

The control circuit consists of an anti-short cycle timer that will not let the compressor re-start before three (3) minutes have elapsed.

Set the thermostat system mode to OFF, and the thermostat fan mode to AUTO. Apply power at the disconnect switch and check the system operations:

Air Circulation

Leave the thermostat system mode on OFF, and set the fan mode to ON. Blower should run continuously. Check the air delivery at the supply registers and adjust register openings for balanced air distribution. Examine ductwork for leaks or obstruction if insuffi cient air is detected.

Set the thermostat fan mode to AUTO.The blower should stop running.

System Heating

Set the thermostat system mode to HEAT and the fan mode to AUTO. Change the thermostat temperature selector above the existing room temperature and check for the discharge of warm air at the supply registers.

System Cooling

Set the thermostat’s system mode to COOL and the fan mode to AUTO. Change the thermostat temperature selector below the existing room temperature.Allow the cooling system to operate for several minutes and check for the discharge of cool air at the supply registers.

Short Cycle Protection

The control circuit is equipped with a time-delay feature for protection against short cycling. With the system operating in the cooling mode, gradually raise the thermostat temperature

setting until the whole system de-energizes. Immediately lower the thermostat temperature to the original setting and verify that the indoor blower is energized. After approximately 3 minutes the compressor and the outdoor fan will energize.

Emergency Heat

(Available only when Electric heat is supplied) Set the thermostat’s system mode to EM HT and the fan mode to either AUTO (intermittent air) or to ON (continuous air). Change the thermostat’s temperature selector above the existing room temperature and check the following:

1.The thermostat auxiliary heat light (RED) should be on.

2.The heat pump compressor and the fan should not run; low voltage circuit remains energized.

3.The blower will run according to the thermostat’s fan mode setting.

Defrost Test Procedure

1. Terminals R & C must have 18 - 30V between them for defrost sequences to initiate.

2With thermostat in heat mode (Y connected to R), short (and hold) the “TEST” pins together. NOTE: This energizes the reversing valve to initiate a forced defrost, bypass the ASCD, and allow the high stage compressor to turn on immediately (if the “REMOVE FOR NO DELAY” jumper at P6 is removed). If the “REMOVE FOR NO DELAY” jumper at P6 is installed, the compressor will energize after

a 30 second delay.

3. Remove the short on the “TEST” pins.

•If the Coil temperature is above the Terminate Temperature setting, the defrost cycle will terminate (reversing valve de-energizes).

•If the coil temperature is below the Terminate Temperature setting, the defrost cycle will continue for 14 minutes (or until the coil temperature rises above the Terminate Temperature setting). Short the “TEST” pins for 1 second or more to force the control out of defrost and back to heating mode (reversing valve de-energized). Compressor will start immediately (if the “REMOVE FOR NO DELAY” jumper is removed). NOTE: If the “REMOVE FOR NO DELAY” jumper is installed, the compressor will energize after a 30 second delay.

Note: If the Y2 thermostat input is energized (on a 2-stage system), the second stage turns on. If the above steps will not initiate a defrost, replace the defrost board.

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