8
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
verify the outdoor unit and indoor blower energize.
2. Verify blower wheel is spinning in direction indicated by
arrow. Feel the air being circulated by the indoor blower
and verify that it is cooler than ambient temperature.
Listen for any unusual noises. If unusual sounds occur,
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
compressor is rotating backwards, shut off main power to
the unit and switch any two field wires at the disconnect.
DO NOT alter unit wiring.
4. Allow the system to operate for several minutes and then
set the temperature selector above room temperature.
Verify the fan and compressor cycle off with the
thermostat. NOTE: The blower should also stop unless
fan switch is set to the ON position.
Table 3. LED Diagnostics for CoreSense
TM
Diagnostics Module
ALERT CODE
ALERT CONDITION
LOCK LEVEL
LOCK INDICATION
Normal Run
Solid Yellow
Normal operation, no trip
N/A
N/A
Code1
Yellow Flash 1
Long run time. Compressor is on running for more than 18 hours.
(Code1 is disabled in Heat Pump Mode)
N/A
N/A
Code2
Yellow Flash 2
Compressor (pressure) trip. Compressor runs for 12 sec to 15 min followed
by a compressor trip condition lasting for more than 7 min.
4x consecutive
Red: Flash2
Yellow: Off
Code3
Yellow Flash 3
Pressure switch cycling. Compressor runs for 12 sec to 15 min followed
by a compressor trip lasting between 35 sec to 7 min.
4x consecutive
or 10x total
Red: Flash3
Yellow: Off
Code4
Yellow Flash 4
Locked rotor. Compressor trips within a compressor run time of 12 sec
and does not start within 35 sec.
10x consecutive
Red: Flash4
Yellow: Off
Code5
Yellow Flash 5
Compressor (moderate run) trip. Compressor runs for 15 min to 18 hrs
followed by a compressor trip lasting longer than 7 min.
4x consecutive
or 10x total
Red: Flash5
Yellow: Off
Code9
Red Flash 9
The current to the PROT terminal is greater than 2A.
Current >2A
for 40ms
Red: Flash9
Yellow: Off
Trip
Solid Red
Demand is present, but compressor is not running.
N/A
N/A
STATUS INDICATOR
STATUS TYPE
DIAGNOSTIC DESCRIPTION
C1
Operating Status
Cooling, 1st Stage
H1
Operating Status
Heating, 1st Stage
SC
Operating Status
Anti Short Cycle Timer
dF
Operating Status
Defrost
_.
Operating Status
Power on, no call for operation
01
Fault
Pressure switch, low
02
Fault
Pressure switch, high
03
Fault
Temperature Sensor, Ambient
04
Fault
Temperature Sensor, Coil
05
Fault
Board
dF
(FLASHING)
Input Error
Forced defrost - test short applied longer than
11 minutes
Table 4. Status Indicators for Defrost Control Board
System Heating
1. Set the thermostat's system mode to HEAT and the
temperature mode to below room temperature.
2. Verify the outdoor unit and indoor fan stop running. After
5 minutes, increase the temperature on the thermostat
to it's maximum setting.
3. Verify the outdoor unit and indoor blower energize. Feel
the air being circulated by the indoor blower and verify
that it is warmer than ambient temperature. Listen for
any unusual noises. If unusual sounds occur, determine
the source of the noise and correct as necessary.
Defrost Control Board Test Pins
• Placing a jumper between the test pins for less than 1
second will bypass the Anti-Short Cycle Timer.
• Placing a jumper between the test pins for more than 1
second will force the unit into a defrost cycle. As soon
as the jumper is removed, the defrost cycle will end as
determined by the typical criteria.
• To determine operating status or fault conditions, refer
for diagnostic description.
Summary of Contents for T4BD-042 Series
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