Goodman Mfg IO-354B installation instructions AIR Flow Adjustments, PSC Motor

CO OLING

	SERVIC E PO RT			REVERSING VALVE
	SERV IC E VA LVE
	SERVIC E PO RT	ACCUM ULATO R
	CO MPRESSOR
EVAPORATOR	DIST RIBU TOR			CONDENSER
	EXPANSION DEV IC E	SERVIC E PO RT
	CHECK VALVE		CH ECK VALVE
INDO OR	OR IFICE SERVIC E		O RIFICE	O U TDO OR
CO IL	VALV E			CO IL
H EATIN G
	SERVIC E PO RT			REVERSING VALVE

SERVIC E VALVE

AC CUM ULATO R

DEFROST CONTROL

During operation the power to the circuit board is controlled by a temperature sensor, which is clamped to a feeder tube entering the outdoor coil. Defrost timing periods of 30,60 and 90 minutes may be selected by connecting the circuit board jumper to 30, 60 and 90 respectively. Accumulation of time for the timing period selected starts when the sensor closes (approximately 31° F), and when the wall thermostat calls for heat. At the end of the timing period, the unit’s defrost cycle will be initiated provided the sensor remains closed. When the sensor opens (approximately 75° F), the defrost cycle is terminated and the timing period is reset. If the defrost cycle is not terminated due to the sensor temperature, a ten minute override interrupts the unit’s defrost period.

AIR FLOW ADJUSTMENTS

The drive on the supply fan is typically set in the middle of the RPM range. The drive motor sheave pitch diameter is field adjustable for the required airflow. Refer to “Drive Adjustments” section below.

CONDENSER

INDO O R

CO IL

CO MPR ESS OR

DISTRIBU TO R	DISTRIBU TOR
	SERV IC E PO RT
CH ECK VALVE	CH ECK VALVE
O RIFICE SERVICE	OR IF ICE
VALVE

EVAPORATOR

OU TDO OR

CO IL

When the final adjustments are complete, the current draw of the motor should be checked and compared to the full load current rating of the motor. The amperage must not ex- ceed the service factor stamped on the motor nameplate. The total airflow must not be less than that required for op- eration of the electric heaters or the furnace.

If an economizer is installed, check the unit operating bal- ance with the economizer at full outside air and at minimum

When the heat pump is on the heating cycle, the outdoor coil is functioning as an evaporator. The temperature of the re- frigerant in the outdoor coil must be below the temperature of the outdoor air in order to extract heat from the air. Thus, the greater the difference in the outdoor temperature and the outdoor coil temperature, the greater the heating capacity of the heat pump. This phenomenon is a characteristic of a heat pump. It is a good practice to provide supplementary heat for all heat pump installations in areas where the tem- perature drops below 45° F. It is also a good practice to provide sufficient supplementary heat to handle the entire heating requirement should there be a component failure of the heat pump, such as a compressor, or refrigerant leak, etc.

Since the temperature of the refrigerant in the outdoor coil on the heating cycle is generally below freezing point, frost forms on the surfaces of the outdoor coil under certain weather con- ditions of temperature and relative humidity. Therefore, it is necessary to reverse the flow of the refrigerant to provide hot gas in the outdoor coil to melt the frost accumulation. This is accomplished by reversing the heat pump to the cooling cycle. At the same time, the outdoor fan stops to hasten the tem- perature rise of the outdoor coil and lessen the time required for defrosting. The indoor blower continues to run and the supplementary heaters are energized.

outside air. Upon completion of the air flow balancing, we recommend replacing the variable pitched motor sheave with a properly-sized fixed sheave. A matching fixed sheave will provide longer belt and bearing life and vibration free opera- tion. Initially, it is best to have a variable pitched motor sheave for the purpose of airflow balancing, but once the balance has been achieved, fixed sheaves maintain alignment and minimize vibration more effectively. For direct drive units, move green wire for fan.

NOTE: Never run CFM below 350 CFM per ton, evaporator freezing or poor unit performance is possible.

PSC MOTOR

Adjust the CFM for the unit by changing the speed tap of the indoor blower motor at the EBTDR “com” connection with the one of the speed taps on “M1” or “M2” (Black-High Speed, Blue-Medium Speed, Red-Low Speed).

X-13 MOTOR

Adjust the CFM for the unit by changing the position of the low voltage leads on the motor terminal block. Green is for Fan Only. Yellow is for Cooling and Heat Pump Heating. Re- fer to Appendix A for blower performance at each speed tap. NOTE: If more than one lead is energized simultaneously, the motor will run at the higher speed.

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