The M3 unit controller has the ability to detect that the rooftop unit power source has the correct frequency, phasing and voltage levels. When this feature is enabled,

the detection of frequency and phasing is determined at power-on and the voltage level is continuously monitored. If any of these is out of range, then an alarm is

logged and the rooftop unit operation is locked out.

1. Alarms Detected at Power-On Start up:

•

121 - LINE FREQ DOES NOT MATCH UNIT CONFIG

•

126 - LINE PHASING DOES NOT MATCH UNIT CONFIG

2. Alarms - Continuously Monitoring

•

122 - 24VAC PRMARY VOLTAGE LOW

•

123 - 24VAC PRIMARY VOLTAGE HIGH

•

134 - 24VAC SECONDARY VOLTAGE LOW

•

125 - 24VAC SECONDARY VOLTAGE HIGH

Alarms 122 through 125 are auto-resetting. The rooftop operation will be restored five (5) minutes after the proper voltage levels are restored. Alarms 121 and 126

requires removing the power and correcting the issue before restoring the rooftop operation

The frequency (60 or 50 Hz) and the phasing (single or three-phase) of the power source is determined by the model number stored in the M3 unit controller. This

model number and enabling/disabling the Phase-Voltage Detection feature can be modified through the M3 unit controller user interface. See the Installation and

Setup Guide for instructions on how to configure the CONFIGURATION ID 2, Position 5. Options are:

N = NOT INSTALLED

1 = ENABLED INTERNAL (LENNOX)

2 = EXTERNAL (A42) PHASE DETECTION ON DI-2

3 = EXTERNAL (A42) PHASE DETECTION ON DI-3

When an event occurs, the M3 unit controller will display a code which corresponds to control function. See table 66. Error codes are stored and can be recalled later.

See the Installation & Setup Guide For The Prodigy M3 unit controller for information about viewing and silencing the alarms via the user interface.

NOTE - Any references in the user interface referencing Advance Airflow actually indicates Smart Airflow

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