3rd cooling set point is 2F (default setting, user selectable 2-3F) warmer than Stage 2. On a call for 3rd Stage cooling the blower of the lag unit is turned on (if not already on – See Blower Operation), and the Stage 3 LED will blink for 10-seconds before going solid, and the lag unit economizer will operate if the outdoor temperature and humidity conditions are below the set point of the economizer control. If outdoor conditions are not acceptable for free cooling the compressor will automatically operate instead of the economizer.
4th cooling set point is 2F (default setting, user selectable 2-3F) warmer than Stage 3. On a call for 4th Stage cooling the lag unit economizer will close and the compressor will operate. If the compressor is already running from 3rd stage cooling call due to outdoor conditions being outside of free cooling range no action occurs at 2nd stage set point.
3.1-Stage Compressor Units with Newer ECONWMT Economizers (See Note A)
1st stage cooling set point is the setting (SP) input into the controller. Factory default is 77F (25C). On a call for cooling the blower of the lead unit will come on immediately (if not already on – See Blower Operation), and the Stage 1 LED will blink for 10-seconds before going solid, at which time the lead unit Y1 cooling output turns on. If the outdoor temperature and humidity conditions are below the set point of the economizer control the lead unit economizer will operate instead of the compressor. If outdoor conditions are not acceptable for free cooling the compressor will automatically operate instead of the economizer.
2nd cooling set point is 4F (default setting, user selectable 2-6F) warmer than Stage 1. On a call for 2nd stage cooling the lead unit Y2 cooling output turns on. If the outdoor temperature and humidity conditions are below the set point of the economizer control the lead unit economizer will continue to operate, and the compressor will operate. If the compressor is already operating on 1st stage cooling because outside free cooling range no action occurs at 2nd cooling set point.
3rd cooling set point is 2F (default setting, user selectable 2-3F) warmer than Stage 2. On a call for 3rd Stage cooling the blower of the lag unit will come on immediately (if not already on – See Blower Operation), and the Stage 3 LED will blink for 10-seconds before going solid, at which time the lag unit Y1 cooling output turns on. The lag unit economizer will operate if the outdoor temperature and humidity conditions are below the set point of the economizer control. If outdoor conditions are not acceptable for free cooling the compressor will automatically operate instead of the economizer.
4th cooling set point is 2F (default setting, user selectable 2-3F) warmer than Stage 3. On a call for 4th Stage cooling the lag unit Y2 cooling output turns on activating the lag unit compressor. If the outdoor temperature and humidity conditions are below the set point of the economizer control the lag unit economizer will continue to operate. If the compressor is already operating on 3rd stage cooling because outside free cooling range no action occurs at 4th cooling set point.
4.2-Stage Compressor Units with Older EIFM Economizers
1st stage cooling set point is the setting (SP) input into the controller. Factory default is 77F (25C). On a call for cooling the blower of the lead unit will come on immediately (if not already on – See Blower Operation), and the Stage 1 LED will blink for 10-seconds before going solid, at which time the lead unit Y1 cooling output turns on. If the outdoor temperature and humidity conditions are below the set point of the economizer control the lead unit economizer will operate instead of the compressor. If outdoor conditions are not acceptable for free cooling the compressor will automatically operate on compressor Stage 1 partial capacity instead of the economizer.
2nd cooling set point is 4F (default setting, user selectable 2-6F) warmer than Stage 1. On a call for 2nd stage cooling the lead unit Y2 cooling output turns on, at which time the lead unit compressor will operate on compressor Stage 2 full capacity. If the compressor is already operating on Stage 1 partial capacity because outside free cooling range the compressor will switch to compressor Stage 2 full capacity.
3rd cooling set point is 2F (default setting, user selectable 2-3F) warmer than Stage 2. On a call for 3rd Stage cooling the blower of the lag unit will come on immediately (if not already on – See Blower Operation), and the Stage 3 LED will blink for 10-seconds before going solid. The lag unit economizer will operate if the outdoor temperature and humidity conditions are below the set point of the economizer control. If outdoor conditions are not acceptable for free cooling the compressor will automatically operate on compressor Stage 1 partial capacity instead of the economizer.
4th cooling set point is 2F (default setting, user selectable 2-3F) warmer than Stage 3. On a call for 4th Stage cooling the lag unit Y2 cooling output turns on, at which time the lag unit compressor will operate on compressor Stage 2 full capacity. If the compressor is already operating on Stage 1 partial capacity because outside free cooling range the compressor will switch to compressor Stage 2 full capacity.
