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8. Turn the thermostat system switch to “OFF” and
disconnect all power when servicing the unit.
WARNING
HIGH VOLTAGE!
Disconnect all power before
servicing or installing this unit.
Multiple power sources may be
present. Failure to do so may cause
property damage, personal injury or
death.
Heat Pump Start-Up Procedure
1.
Check the cooling mode for the heat pump in
the same manner as above. The reversing valve
is energized when the thermostat is placed in
the cooling position. A clicking sound should be
noticeable from the reversing valve. By lowering the
temperature setting to call for cooling, the solenoid
valve is energized. The compressor, blower and fan
should then be running. After the cooling mode is
checked out, turn the thermostat system switch to
“OFF”.
2. Turn the thermostat system switch to “HEAT” and fan
switch to “AUTO”.
3. Slowly raise the heating temperature setting. When
the heating first stage makes contact, stop raising
the temperature setting.. The compressor, blower
and fan should now be running with the reversing
valve in the deenergized (heating) position. After
giving the unit time to settle out, make sure the unit
is supplying heated air.
4. If the outdoor ambient is above 80°F, the unit may
trip on its high-pressure cutout when in heating
mode. The compressor should stop. The heating
cycle must be thoroughly checked, so postpone
the test to another day when conditions are more
suitable but, DO NOT FAIL TO TEST.
5. If the outdoor ambient is low and the unit operates
properly in the heating cycle, you may check the
pressure cutout operation by blocking off the indoor
return air until the unit trips.
6.
If unit operates properly in the heating cycle, raise
the temperature setting until the heating second
stage makes contact. Supplemental resistance
heat, if installed should now come on. Make sure it
operates properly.
NOTE: 15.2 SEER2 model has two stages of
compressor heat. During resistance heat test,
increase temperature setting until third stage heat
is energized.
NOTE: If outdoor thermostats are installed the
outdoor ambient must be below the set point of
these thermostats for the heaters to operate. It
may be necessary to jumper these thermostats to
check heater operation if outdoor ambient is mild.
If the outdoor ambient is low and the unit operates properly
in the heating cycle, you may check the pressure cutout
operation by blocking off the indoor return air until the unit
trips. If unit operates properly in the heating cycle, raise
the temperature setting until the heating second stage
makes contact. Supplemental resistance heat, if installed
should now come on. Make sure it operates properly.
7. THERMOSTATS WITH EMERGENCY HEAT. For
thermostats with an emergency heat switch, raise
the temperature setting until the heating second
stage makes contact. The emergency heat switch
is located at the bottom of the thermostat. Move the
switch to emergency heat. The heat pump will stop,
the blower will continue to run, all heaters will come
on and the thermostat emergency heat light will
come on.
8. If checking the unit in the wintertime, when the
outdoor coil is cold enough to acuate the defrost
control, observe at least one defrost cycle to make
sure the unit defrosts completely.
Final System Checks
1.
Check to see if all supply and return air grilles are
adjusted and the air distribution system is balanced
for the best compromise between heating and
cooling.
2. Check for air leaks in the ductwork.
3. Check air flow and refrigerant charge. See Sections
on
Air Flow Measurement and Adjustment
and
Checking Charge.
4. Ensure the unit is free of “rattles”, and the tubing
in the unit is free from excessive vibration. Also
make sure tubes or lines are not rubbing against
each other or sheet metal surfaces or edges. If
discovered, ensure issue is corrected.
5. Set the thermostat at the appropriate setting for
cooling and heating or automatic changeover for
normal use.
6. Ensure the Owner is instructed on the unit operation,
filter, servicing, correct thermostat operation, etc.
NOTE: The “Air Conditioner Start-Up Procedure”
is a recommended step as it serves as a system
indicator that the unit will operate normally.
Refrigeration Performance Check
Check that compressor RLA corresponds to values shown
in Appendix B. RLA draw can be much lower than values
listed at low load conditions and low ambient condensing
temperatures. Values in Appendix B can slightly exceed
at high load conditions and high ambient condensing
temperatures.
HEAT PUMP OPERATION
Cooling Cycle
When the heat pump is in the cooling cycle, it operates
exactly as an Air Conditioner Unit.
