
8
Short Cycle Protection
1.SetthethermostatsystemmodetoCOOL.Observethe
temperaturesettingofthethermostatandgraduallyraise
theset-pointtemperatureuntiltheunitde-energizes.
2.Immediately lower the set point temperature of the
thermostat to its original setting and verify that the
indoorblowerisenergizedandoutdoorunitremains
de-energized.
3.After approximately 5 minutes, verify the outdoor unit
energizesandthetemperatureofthedischargeairis
cooler than the room temperature.
System Cooling
1.Set the thermostat’s system mode to COOL and the
fan mode to AUTO. Gradually lower the thermostat
temperature setpoint below room temperature and
verifytheoutdoorunitandindoorblowerenergize.
2.Verifyblowerwheelisspinningindirectionindicatedby
arrow.Feeltheairbeingcirculatedbytheindoorblower
and verify that it is cooler than ambient temperature.
Listenforany unusualnoises.If unusualsoundsoccur,
determine the source of the noise and correct as
necessary.
3.Verify HI and LO refrigerant pressures.
NOTE: If refrigerant pressures are abnormal and the
compressorisrotatingbackwards,shutoffmainpowerto
theunitandswitchanytwofieldwiresatthedisconnect.
DO NOT alter unit wiring.
4.Allowthesystemtooperateforseveralminutesandthen
set the temperature selector above room temperature.
Verify the fan and compressor cycle off with the
thermostat.NOTE:Theblowershouldalsostopunless
fan switch is set to the ON position.
System Heating
1.Set the thermostat's system mode to HEAT and the
temperature mode to below room temperature.
2.Verifytheoutdoorunitandindoorfanstoprunning.After
5minutes,increasethetemperature on thethermostat
to it's maximum setting.
3.Verifytheoutdoorunitandindoorblowerenergize.Feel
the air being circulated by the indoor blower and verify
that it is warmer than ambient temperature. Listen for
anyunusualnoises.Ifunusualsoundsoccur,determine
the source of the noise and correct as necessary.
Defrost CycleTimer
Thedefrostcycletimercontrolsthetimeintervalofthehot
gasdefrostafterthedefrostsensor closes.Itis located in
the lower left corner of the defrost control board on the of
thecontrolpanel.Threeintervalsettingsareavailable:30,
60, and 90 minutes.Time setting selection is dependent
on the climate where the unit is being installed.
• Example1:Dry climateofSouthern Arizona-A 90
minute setting is recommended.
• Example2:MoistclimateofSeattle,Washington-A
30 minute setting is recommended.
To set the cycle timer, place the timing pin on the defrost
control board to the desired time interval post.
NOTE: All units are shipped from the factory with the
default time setting of 30 minutes. Longer settings are
recommended for drier climate areas and shorter time
intervals are recommended for moist climate areas.
Maximumheatingperformancecanbeacheivedbysetting
the time to 90 minutes.
Defrost Control Board
Operational Information
• Terminals R -RC must have 24±V present between
them in order for the time delay and defrost sequences
to be operational.
• Jumpering the T2 -DFT test pins will communicate
to the board that the defrost T-stat is closed (if the
compressorisrunning).Thedefrostthermostattellsthe
board whether a defrost cycle needs to be started or
terminated.NOTE:The defrostT-stat is closed at 32° F
or below and is open at 68° F or above, but it’s state is
unknown if the temperature is between 32° F and 68°
F.
• With the DFT closed, the unit will run for 30/60/90
minutes in heat mode and then defrost the outdoor
coil.The defrost willturn offtheoutdoorfan,turn onthe
compressorandraisethecoiltemperatureto68°F.This
will open the DFT and terminate the defrost.If the DFT
does not open the defrost will end after 10 minutes.
• Toover-ridethedefrostboarrdandinitiateafasterdefrost
test in 5, 10 or 15 seconds as determined by the 30, 60
or 90 minute defrost pin settings (factory setting is 30
minutes),jumpertheTEST terminaltotheC(common)
terminal while the compressor is in heat mode.
– This will bypass the compressor off delay when the
unitgoesintodefrosttestandifleftindefrosttest,the
delay will be bypassed when the test is terminated
by the processor. NOTE: If the jumper is removed
beforethe testisover,the processorwillperform the
remainder of a normal defrost. See bullett 2 above.
• To switch from no-delay to delay, remove the pin from
the no - delay pin location and shift it to the delay pin
location.The delay/no-delay pin concerns compressor
operation during defrosts.The default setting is delay.
– Reciprocating compressors should only use this
setting in conjunction with an approved hard start
kit.
– Scroll compressors that have noise issues while
going into or coming out of defrost should use this
30 second delay to reduce the defrost noise.
– Manuallyinitiatingadefrostwillcausethecompressor
to run continually when entering defrost.
Normal defrost operation
To test normal defrost operation when the temperature is
above 35° F, jumper Rto DFT on the board and allow the
unit to run for 30 minutes. Defrost will continue until the
Rto DFT jumper is removed or for 10 minutes. Remove
the jumper.