20
NDS OUTDOOR SPLIT INSTALLATION MANUAL
Green "POWER" LED - module has power
Red "TRIP" LED - Thermostat "Y" demand signal is present, but the compressor is not running.
Yellow "ALERT" LED
LED Description
Cause
Flash Code 1
Long Run Time
Not applicable
Flash Code 2
System Pressure Trip
Not applicable
Flash Code 3
Short Cycling
Compressor run time of less than 3 minutes on 4 consecutive cycles
Flash Code 4
Locked Rotor
Four consecutive compressor protector trips indicating compressor won't start
Flash Code 5
Open Circuit
"Y" thermostat demand signal with no compressor current
Flash Code 6
Open Start Circuit
"Y" thermostat demand signal with no current in the start circuit
Flash Code 7
Open Run Circuit
"Y" thermostat demand signal with no current in the run circuit
Flash Code 8
Welded Contactor
Current detected with no "Y" thermostat demand signal present
Flash Code 9
Low Voltage
Less than 17 VAC detected in control circuit
* Flash code number corresponds to a number of LED flashes, followed by a pause and then repeated.
* TRIP and ALERT LEDs flashing at the same time indicates control circuit voltage is too low for operation.
* Reset ALERT flash code by removing 24 VAC power from module.
* Last ALERT flash code is displayed for 1 minute after module is powered on.
Resetting Comfort Alert Codes
Alert codes can be reset manually by cycling power off and on to the Comfort Alert module. Alert codes will reset automatically if
conditions return to normal.
Flash Code Number
LED Description
Automatic Reset of Alert Codes
Flash Code 1
Long Run Time
Not applicable
Flash Code 2
System Pressure Trip
Not applicable
Flash Code 3
Short Cycling
Four "alert free" on and off cycles to reset automatically
Flash Code 4
Locked Rotor
Four "alert free" on and off cycles to reset automatically
Flash Code 5
Open Circuit
One "alert free" on and off cycles to reset automatically
Flash Code 6
Open Start Circuit
One "alert free" on and off cycles to reset automatically
Flash Code 7
Open Run Circuit
One "alert free" on and off cycles to reset automatically
Flash Code 8
Welded Contactor
One "alert free" on and off cycles to reset automatically
Flash Code 9
Low Voltage
Resets when voltage rises above 19 VAC
* Reset ALERT flash code by removing 24 VAC power from module.
Comfort Alert Flash Codes
Microprocessor Control cont.
Compressor Monitoring/Comfort Alert
The Comfort Alert displays abnormal compressor
conditions through a unique flash code and communicates
the conditions to the heat pump microprocessor control.
The heat pump microprocessor will determine which fault
to act on and ignore. Fault codes 2 (system pressure),
4 (locked rotor), 6 (open start circuit), and 7 (open run
circuit) will result in a lockout. All other fault codes are
passive. All compressor alerts are displayed on the module
by flashing the yellow Alert LED a specific number of times
consecutively followed by a pause, and then repeated. The
number of consecutive flashes or “Flash Code” correlates
to a specific abnormal condition. The red “TRIP” LED
means there is a thermostat demand signal “Y” present but
the compressor is not running. The green “POWER” LED
means the module has power.
