Unit Component Operation; Freeze-Stats (S49, S50, S53 And S95); High Pressure Switches (S4, S7, S28 And S96) (Standard And High Efficient Units); Thermal Protection Switches (S5, S8, S31 And S180) - Lennox Prodigy 2.0 Application Manual

3. Unit Component Operation

3.1. Compressor Protection and Delays
3.1.1. Compressor Minimum Run and Off Times
Energence Ultra-High Efficiency Units
Energence Ultra­High Efficiency Units have both compressor Minimum Run Time (default 240 seconds) and Minimum OFF
Time (default 300 seconds) always enabled. This configuration cannot be altered, but values can be adjusted (refer to the
Appendix C for details)
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 91 (COMP MIN RUN TIME)
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 89 (COMP MIN OFF DELAY)
Other Energence Models
On all other Energence models, Minimum OFF Time is, by default, enabled while Minimum Run Time is disabled.
This configuration can be altered by modifying Parameter 225 that can only be access using Unit Controller Software (UCS)
running on a computer. Checking the 'UNIT_OPERATION_DISABLE_SLUG_2_0' option will enable Minimum Run Time
(Parameter 91) and disable the Minimum OFF Time (parameter 89) protection for 3-phase systems only. Refer to the
Appendix C for defaults and ranges.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 91 (COMP MIN RUN TIME)
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 89 (COMP MIN OFF DELAY)
3.1.2.

Freeze-stats (S49, S50, S53 and S95)

Normally closed freeze-stat opens when evaporator coil temperature drops to de-energize the corresponding compressor.
Once coil temperature rises the switch automatically resets to allow compressor operation. The corresponding compressor
is locked out after three occurrences (default) which is set using Parameter 81. Adjustable range is 1 to 3 occurrences.
When a compressor is de-energized due to an open freeze-stat switch, alarms 32 (S49 switch), 34 (S50 switch), alarm 36
(S53 switch) or 38 (S95 switch) is issued.
NOTE: No alarms are recorded during free cooling or off cycles between cooling calls.
The corresponding compressor is locked out after three occurrences (default) which is set using Parameter 81.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 81 (MAX FREEZE STAT OCC)
3.1.3. High Pressure Switches (S4, S7, S28 and S96)
High pressure switches open on a pressure rise to de-energize the corresponding compressor for 300 seconds (five
minutes (default) which is set using Parameter 110. Switches automatically reset when pressure drops. The corresponding
compressor is locked out after three occurrences (default) which is set using Parameter 98. Adjustable range is 1 to 7
occurrences. When a compressor is de-energized due to an open high pressure switch, alarms 12 (S4 switch), 14 (S7
switch), 16 (S28 switch) or 18 (S96) is issued.
The corresponding compressor is locked out after three occurrences (default) which is set using Parameter 98.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 98 (MAX HP OCCURRENCES)
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