WHEN THE SYSTEM IS FUNCTIONING PROPERLY AND
THE OWNER HAS BEEN FULLY INSTRUCTED, SECURE
THE OWNER’S APPROVAL.
INDICATIONS OF PROPER OPERATION
COOLING
Cooling operation is the same as any conventional air condi-
tioning unit.
1. The outdoor fan should be running, with warm air being
discharged from the top of the unit.
2. The indoor blower (furnace or air handler) will be operating,
discharging cool air from the ducts.
3. The vapor line at the outdoor unit will feel cool to the touch.
4. The liquid line at the outdoor unit will feel warm to the touch.
HEATING
Indications of proper Heating operation is as follows:
1. The outdoor fan should be running, with cool air being
discharged from the top of the unit.
2. The indoor blower (furnace or air handler) will be operating,
discharging warm air from the ducts.
3. The vapor line at the outdoor unit will feel warm to the touch.
4. The liquid line at the outdoor unit will feel cool to the touch.
SYSTEM OPERATION
See Figure 9 to trace the flow of refrigerant through the system.
WITH POWER TO UNIT AND THERMOSTAT IN COOLING
POSITION.
1. Reversing valve is energized through thermostat system
switch to position refrigerant circuit for cooling operation. In
the cooling cycle, discharge gas is pumped to the outdoor
coil which is the condenser. The indoor coil is the evapora-
tor.
2. If fan switch is in “ON” position, a circuit is made through
blower relay to provide continuous blower operation.
3. When thermostat cooling contact closes, a circuit is made
to energize contactor and start the system, if the compres-
sor has been off 5 minutes. With fan switch in “AUTO”
position, a circuit is made from thermostat cooling contact
through blower relay to provide blower operation.
4. System will cycle with thermostat demand to provide cool-
ing as needed.
WITH POWER TO UNIT AND THERMOSTAT IN HEATING
POSITION
1. Reversing valve is de-energized to position refrigerant
circuit for heating operation. In the heating cycle, discharge
gas is pumped to the indoor coil which is the condenser.
The outdoor coil is the evaporator.
2. If fan switch is in “ON” position, a circuit is made through
blower relay to provide continuous blower operation.
3. When first stage of thermostat heating contact closes, a
circuit is made through the control to energize contactor
FLOW
CONTROL
DEVICE
INDOOR
COIL
STRAINER
COMPRESSOR
4-WAY
REVERSING
VALVE*
SUCTION
ACCUM.
CAPILLARY TUBE
EXPANSION DEVICE
OUTDOOR
COIL
COOLING CYCLE FLOW
HEATING CYCLE FLOW
* SHOWN IN COOLING POSITION
FILTER/ DRIER-CHECK VALVE
FIELD CONNECTED LINE
FIELD CONNECTED LINE
FIGURE 9 - HEAT PUMP FLOW DIAGRAM
515.26-N1Y
10
Central Environmental Systems
