Installation Guide
7
Compressor Protection
The CoreSense
TM
 Diagnostics module utilizes proprietary 
algorithms to protect the compressor and system from 
repeated trips of system pressure controls and the 
compressor internal overload. The protection terminal 
of the module should be wired in series with the system 
low pressure and high pressure cutouts, as well as the 
compressor contactor. When the module detects a series 
of trips as described below, it will activate a lockout feature 
that opens the normally closed protection contacts in 
the module, thereby cutting power to the contactor and 
shutting off the compressor.
Resetting Alert Codes
When the CoreSense
TM
 Diagnostics module has detected a 
series of adverse conditions that have caused it to lockout 
the compressor, and after the issue has been resolved, 
it is necessary to manually reset the module in order to 
clear the present alert code.
The primary way of clearing the code and resetting the 
alert is to press the reset button located on the module. 
NOTE: Pressing the reset will require a pin or a mini 
electronics screwdriver. This button must be pressed and 
held for a minimum of one second for the module to be 
reset. Pressing the reset button clears the immediate lock 
code and the seven day operating history. It will not clear 
the permanent module history. In the case of the three-
wire module, the codes can be reset or cleared by cycling 
power to the module. This can be done by disengaging 
the Common (C) terminal. This will not clear the seven 
day operating history.
START UP & ADJUSTMENTS
Pre-Start Check List
√  Verify the unit is level and has sufficient clearances for 
unobstructed airflow.
√  Verify the outdoor coil and top of the unit are free from 
obstructions and debris, and all equipment access/
control panels are in place.
√  Verify that the line voltage power leads are securely 
connected and the unit is properly grounded.
√  Verify that the low voltage wires are securely connected 
to the correct leads on the low voltage terminal strip.
√  Verify that the power supply branch circuit overcurrent 
protection is sized properly.
√  Verify that the thermostat is wired correctly.
Start-Up Procedures
 WARNING:
This unit is equipped with a crankcase heater. 
Allow 24 hours prior to continuing the start up 
procedures to allow for heating of the refrigerant 
compressor crankcase. Failure to comply may 
result in damage and could cause premature 
failure of the system. This warning should be 
followed at initial start up and any time the power 
has been removed for 12 hours or longer.
Air Circulation - Indoor Blower
1. Set the thermostat system mode on OFF and the fan 
mode to ON.
2. Verify the blower runs continuously. Check the air delivery 
at the supply registers and adjust register openings for 
balanced air distribution. If insufficient air is detected, 
examine ductwork for leaks or obstructions.
3. Set the thermostat fan mode to AUTO and verify the 
blower stops running.
Table 3. LED Diagnostics for CoreSense
TM
 Diagnostics Module
ALERT CODE ALERT CONDITION LOCKLEVEL 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










