Gas Valve Sensor; Gas Heat Valve Delays; Thermostat Bounce Delay (Local Thermostat Mode Only); Return Air Temperature Limits - Lennox Prodigy 2.0 Application Manual

3.2.4. Gas Valve Sensor Activation Feedback
If M3 Unit Controller does not detect that gas valve is energized within two minutes after a heating demand, it will display and
store error code 58 for gas heat section 1 and alarm 68 for gas heat section 2.
If the gas valve is energized and de-energized three times (default) during a single heating demand, the M3 will display and
store error code 59 for the gas heat section 1 and alarm 60 for gas heat section 2. The service relay will be activated if
configured.
The default setting for Parameter 73 is three occurrences with a valid range setting of 1 to 5.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 73 (MAX GV SENSE OCC)
If the gas valve is energized without a heating demand the M3 Unit Controller will de­energize all heat control outputs. The
Service Output will be turned on if it is configured for alarm reporting (default setting).
3.2.5.

Gas Heat Valve Delays

The M3 Unit Controller has a model dependent time delay setting (Parameter 69 - HT GAS HI FIRE DLAY) between first-
and second-stages. Parameter 70 - HT GAS OFF DELAY provides timed-off delay that will prevent gas heat operation until
100 seconds (factory default) has passed from the previous cycle. Settable delay options for Parameter 70 are 30 to 300
seconds.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 70 (HT GAS OFF DELAY)
3.3. Miscellaneous Components
3.3.1. Thermostat Bounce Delay (Wired Thermostat Mode Only)
The M3 Unit Controller will automatically ignore wired thermostat inputs for three seconds to prevent sporadic on/off cycling.
The function is non-adjustable.
3.3.2.

Return Air Temperature Limits

The M3 Unit controller may be set up to monitor return air temperature and interrupt the demand if return temperature is
above (in heating) or below (in cooling) adjustable limits. Alarm codes 40 or 41 are displayed but not stored in memory for
recall.
•
Adjusting Parameter 113 enables return room temperature limits. Default is 0 (OFF). To enable set to 1 (ON). Go to
SETTINGS > RTU OPTION > EDIT PARAMETER = 113 (EN RET AIR TMP LMT)
•
Adjusting Parameter 114 is used to interrupt a cooling demand. Default is 65.0°F. Adjustable range is 60.0°F to 80.0°F.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 114 (COOL RET AIR LIMIT)
•
Adjusting Parameter 115 is used to interrupt a heating demand. Default is 85.0°F. Adjustable range is 60.0°F to 100.0°F.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 115 (HEAT RET AIR LIMIT)
3.3.3.

Smoke Detector (A171 and A172 - Optional)

A171 is for return air and A172 is for supply air. If smoke detector senses smoke, normally open contacts close. The M3 Unit
Controller by default turns off the unit and closes the economizer dampers. Variations in damper position, power exhaust
and blower operation may be changed by Parameter 109. Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 109
(SMOKE ALARM CONTROL)
Parameter
Blower
109 Option
0 Off
2 Off
9 On
10 On
11 On
Table 10. Smoke Alarm Control
Exhaust (1 Fresh Air
or 2 Stage) Damper
Off Closed
On Closed
Off Open
On Closed
On Open
Description
Unit Off
Negative Pressure with blower exhaust fan at fixed speed
Positive Pressure
Negative Pressure with blower exhaust fan at fixed speed
Purge - Exhaust fan at fixed speed
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