Heat Pump Operation; Cooling Cycle; Heating Cycle; Defrost Control - Goodman GPH1624M41 Installation Instructions Manual

Indoor Blower Motor
All GPH16 M series model package units use a EEM blower motor. The EEM motor is a 3 Phase brushless DC (single phase AC
input), ball bearing construction motor with an integral control module with an internal FCC B EMI filter. The EEM motor is
continuously powered with line voltage. The switched 24 volt control signal is controlled by the thermostat in the cooling and heat
pump mode.
C C
OOLING YCLE
When the heat pump is in the cooling cycle, it operates exactly
as a Air Conditioner unit.
H C
EATING YCLE
The heat pump operates in the heating cycle by redirecting
refrigerant flow through the refrigerant circuit external to the
compressor. This is accomplished with through the reversing
valve. Hot discharge vapor from the compressor is directed to
the indoor coil (evaporator on the cooling cycle) where the heat
is removed, and the vapor condenses to liquid. It then goes
through the expansion device to the outdoor coil (condenser on
the cooling cycle) where the liquid is evaporated, and the vapor
goes to the compressor.
When the solenoid valve coil is operated either from heating to
cooling or vice versa, the piston in the reversing valve to the low
pressure (high pressure) reverse positions in the reversing valve.
The following figures show a schematic of a heat pump on the
cooling cycle and the heating cycle. In addition to a reversing
valve, a heat pump is equipped with an expansion device and
check valve for the indoor coil, and similar equipment for the
outdoor coil. It is also provided with a defrost control system.
The expansion devices are flowrator distributors and perform
the same function on the heating cycle as on the cooling cycle.
The flowrator distributors also act as check valves to allow for
the reverse of refrigerant flow.
When the heat pump is on the heating cycle, the outdoor coil is
functioning as an evaporator. The temperature of the refrigerant
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 temperature 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 conditions 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 temperature rise of the outdoor
coil and lessen the time required for defrosting. The indoor blower continues to run and the supplementary heaters are energized.
D C
EFROST ONTROL
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 setting the circuit board jumper to 30, 60 and
90 respectively. Accumulation of time for the timing period selected starts when the sensor closes (approximately 34°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 60°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 twelve minute override interrupts the unit's defrost period.

HEAT PUMP OPERATION

C O O LIN G
IN DO O R
C O IL
H E A TIN G
IN D O O R
CO IL
11
S E RV IC E P O RT
S E RV IC E VA LV E
S E R V IC E P O R T A C C U M U LA TO R
C O M P R E S S O R
D IS T RIB U TO R
E X P A NS IO N D EV IC E
S E R V IC E PO R T
C H E C K V AL V E
O R IF ICE
S E R V IC E
V A LV E
S E R V IC E P O R T
S E R V IC E V A LV E
A C CU M U LA TO R
CO M P R E SS O R
DIS T R IBU TO R
S E RV IC E PO R T
C H E CK V A LV E
O R IF IC E
S E R V IC E
VA LV E
R E V E RS IN G V A LV E
C H E CK V A LV E
O R IF IC E O U TDO O R
CO IL
RE V E R S IN G V A L V E
DIS T R IB U TO R
CH E C K VA L V E
O R IF IC E O U TDO O R
C O IL