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NSZ/NDZ 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
Eighteen consecutive hours of compressor run time
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
Thirty "alert free" on and off cycles to reset automatically
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 condi-
tions 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 re-
sult in a lockout. All other fault codes are passive. All com-
pressor 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.
