835961-UIM-D-0213
12
Johnson Controls Unitary Products
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 W1/66 terminal immediately.
PRESSURE SWITCH FAULT & LOCKOUT
The heat pump is equipped with a pressure switch, loss of charge
switch and an over temp switch (units equipped with scroll compressor)
that are connected to the control at the pressure switch terminals. If one
of these switches input opens for more than 40 milliseconds, 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 compressor 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 X/L output with the appropriate flash code.
The control will reset the soft lockout condition when any of the follow-
ing occur following 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 satisfied 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.
When the soft lockout condition is reset, the control will stop displaying
the fault code and will respond to thermostat inputs normally.
SECTION VI: 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 is permanently lubricated and does not
require periodic oiling.
3. If the coil needs to be cleaned, it should be washed with Calgon Coil-
clean (mix one part Coilclean to seven parts water). Allow solution to
remain on coil for 30 minutes before rinsing with clean water. Solu-
tion should not be permitted to come in contact with painted sur-
faces.
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.
SUBCOOLING CHARGE TABLE IS ON THE UNIT RATING
PLATE.
FIGURE 13:
Defrost Operation Curves
REGION C
TERMINATE CURVE
INHIBIT CURVE
INITIA
TE
CUR
VE
REGION A
REGION B
REGION D
REGION E
AMBIENT TEMPERATURE
LIQUID LINE (COIL)
TEMPERA
TURE
Defrost prevented from starting
No call for defrost
Time Defrost (6 hour) prevented
No call for Defrost
Time Defrost (6 hour) allowed
Call for Defrost
Defrost Terminated
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.
