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5121495-UIM-E-0716
COOLING OPERATION
During cooling operation, the control will receive thermostat signals at
the Y and O input terminals. The control will energize the M compressor
output terminal. This signal energizes the coil of the compressor con-
tactor causing the compressor to run. The control also delivers power to
the COND FAN terminals causing the outdoor fan to operate. The con-
trol energizes the REV VALVE terminal with 24VAC to switch the
reversing valve.
HEATING OPERATION
During normal heating mode, the control will receive a thermostat signal
at the Y input terminal. The control will energize the M compressor out-
put terminal. This signal energizes the coil of the compressor contactor
causing the compressor to run. The control also delivers power to the
COND FAN terminals causing the outdoor fan to operate. The reversing
valve is not energized in heating mode.
EMERGENCY HEAT
When the thermostat calls for emergency heat operation (W signal with-
out a Y signal), the control will de-energize the compressor and ener-
gize the Wout terminal immediately.
PRESSURE SWITCH FAULT & LOCKOUT
The heat pump is equipped with a pressure switch and loss of charge
switch that are connected to the control at the pressure switch termi-
nals. If one of these switches input opens for more than 40 millisec-
onds, the control will de-energize the compressor. If the switch closes
and a thermostat call for compressor operation is present, the control
will apply the five-minute anti short-cycle delay timer and start the com-
pressor when the timer expires.
When the compressor is started following a switch fault, the control will
start a six-hour timer based on accumulated compressor run time. If the
control senses another opening of the switch before the timer expires, it
will cause a soft lockout condition. The second opening of the switch
must be greater than 160 milliseconds for the lockout to occur. If the
second opening is between 40 and 160 milliseconds, the control will de-
energize the compressor but not cause a soft lockout condition. If the
control does not sense a second switch opening before the six-hour
timer expires, the timer and counter will be reset.
During the soft lockout mode, the control will de-energize the compres-
sor and energize the LED output with the appropriate flash code.
The control will reset the soft lockout condition when any of the follow-
ing occur after removal of the fault condition.
1. Power is cycled to the R or Y inputs of the control. This will cause
the soft lockout condition to be reset when the thermostat is satis-
fied or when the thermostat is set to SYSTEM OFF and back to
HEAT or COOL mode.
2. The TEST terminals are shorted for more than two seconds.
18
When the soft lockout condition is reset, the control will stop displaying
the fault code and will respond to thermostat inputs normally.
SECTION X: INSTRUCTING THE OWNER
Assist owner with processing warranty cards and/or online registration.
Review Owners Guide and provide a copy to the owner and guidance
on proper operation and maintenance. Instruct the owner or the opera-
tor how to start, stop and adjust temperature setting.
When applicable, instruct the owner that the compressor is equipped
with a crankcase heater to prevent the migration of refrigerant to the
compressor during the OFF cycle. The heater is energized only when
the unit is not running. If the main switch is disconnected for long peri-
ods of shut down, do not attempt to start the unit until 8 hours after the
switch has been connected. This will allow sufficient time for all liquid
refrigerant to be driven out of the compressor.
The installer should also instruct the owner on proper operation and
maintenance of all other system components.
MAINTENANCE
1. Dirt should not be allowed to accumulate on the outdoor coils or
other parts in the air circuit. Clean as often as necessary to keep the
unit clean. Use a brush, vacuum cleaner attachment, or other suit-
able means.
2. The outdoor fan motor bearings are permanently lubricated and do
not require periodic oiling.
3. If the coil needs to be cleaned, it should be washed with Calgon
Coilclean (mix one part Coilclean to seven parts water). Allow solu-
tion to remain on coil for 30 minutes before rinsing with clean water.
Solution should not be permitted to come in contact with painted
surfaces.
4. Refer to the furnace or air handler instructions for filter and blower
motor maintenance.
5. The indoor coil and drain pan should be inspected and cleaned reg-
ularly to prevent odors and assure proper drainage.
CAUTION
!
IT IS UNLAWFUL TO KNOWINGLY VENT, RELEASE OR DIS-
CHARGE REFRIGERANT INTO THE OPEN AIR DURING REPAIR,
SERVICE, MAINTENANCE OR THE FINAL DISPOSAL OF THIS
UNIT.
COOLING CHARGE TABLE IS ON THE INSIDE OF THE CONTROL
BOX COVER.
Outdoor Unit
Defrost Jumper Pin Setting
18 24 30 35 36 42 48 60
2
2
2
3
3
2
Johnson Controls Unitary Products
4
2
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