Service Relay; Service Relay Operation; System Relative Humidity Options; System Indoor Air Quality / Carbon Dioxide Options - Lennox PRODIGY2.0 Application Manual

20. Service Relay

20.1. Service Relay Operation

The M3 unit controller Service Relay output (A55_P298-8) default operation indicates that service is required.
If the default operation is not required, the Service Relay output may be used as a control output. Use parameter 186 to
choose the input which will trigger the Service Relay output. The formula X + (32
If parameter 186 input sources 7-9 are used, the set point and dead-band must be set with parameter 187, parameter
188, parameter 189, parameters 190, 191 and 192.

20.2. System Relative Humidity Options

Option Description
•
0 - Hysteresis
•
•
1 - Window
•
NOTE: Fixed 3% relative humidity hysteresis on options 1 - 3
•
2 - Delayed ON
•
3 - Delayed OFF

20.3. System Indoor Air Quality / Carbon Dioxide Options

Option Description
•
0 - Hysteresis
•
•
1 - Window
•
•
2 - Delayed ON
•
3 - Delayed OFF

20.4. System Outdoor Air Temperature Operation

Option Description
•
0 - Hysteresis
•
•
1 - Window
•
•
2 - Delayed ON
•
3 - Delayed OFF
Example 1: Use the Service output to energize a dehumidifier at 60% relative humidity and turn off at 55% relative
humidity. (Refer to figure 24.)
Table 52. System Relative Humidity Options
ON when relative humidity is equal to or greater than parameter 188 setting.
OFF when relative humidity is less than parameter 188 setting minus parameter 191.
ON when relative humidity is within range.
Parameter 188 plus parameter 191
Only ON when relative humidity is greater than parameter 188. Otherwise service delay will be OFF.
When relative humidity falls below parameter 188 the service delay is turned OFF once parameter 193 setting
(seconds) is reached.
Table 53. System IAQ / Carbon Dioxide Options
ON when indoor air quality/carbon dioxide is greater than parameter 187 setting.
OFF when indoor air quality/carbon dioxide is less than parameter 187 minus parameter 190 setting.
ON when indoor air quality/CO2 within range.
Parameter 187 (SRV OUTPT SP CO2) plus parameter 190 .
ON when indoor air quality/CO2 is greater than parameter 187. Otherwise service delay will be OFF.
When indoor air quality/CO2 falls below parameter 187 the service delay is turned OFF once parameter 193 setting
(seconds) is reached.
Table 54. System Outdoor Air Temperature Operation Options
ON when outdoor air temperature is greater parameter 189 setting.
OFF when outdoor air temperature is less than parameter 189 setting.
ON when outdoor air temperature is within range.
Parameter 189 plus parameter 192.
ON when outdoor air temperature is greater than parameter 189 setting. Otherwise service delay will be OFF.
When outdoor air temperature falls below parameter 189 the service delay is turned off once parameter 193 setting
(seconds) is reached.
x
Y) + (16
79
x
Z) is used to select the option.