Sequence of Operation
ReliaTel Control Cooling with an Economizer
The economizer is utilized to control the zone temperature providing the outside air conditions are suitable. Outside air is drawn into the unit through modulating dampers. When cooling is required and economizing is possible, the RTRM sends the cooling request to the unit economizer actuator to open the economizer damper.
The RTRM tries to cool the zone utilizing the economizer to slightly below the zone temperature setpoint. If the mixed air sensor (MAS) senses that the mixed air temperature is below 53°F, the damper modulates toward the closed position.
If the zone temperature continues to rise above the zone temperature setpoint control band and the economizer damper is fully open, the RTRM energizes the modulating eFlex compressor. If the zone temperature continues to rise above the zone temperature setpoint control band and the economizer damper is fully open, the RTRM instructs the compressor inverter drive to increase the compressor speed to allow more compressor capacity.
If the eFlex compressor is running at its maximum capacity and the zone temperature continues to rise above the zone temperature setpoint control band and the economizer damper is fully open, the RTRM energizes the first fixed speed compressor, while simultaneously instructing the compressor inverter drive to decrease the eFlex compressor capacity to allow a smooth system capacity transition. If the zone temperature continues to rise above the zone temperature setpoint control band and the economizer damper is fully open, the RTRM instructs the compressor inverter drive to increase the eFlex compressor speed to allow more compressor capacity.
If the eFlex compressor is running at its maximum capacity and the zone temperature continues to rise above the zone temperature setpoint control band and the economizer damper is fully open, the RTRM energizes the second fixed speed compressor, while simultaneously decreasing the eFlex compressor speed to allow a smooth transition of system cooling capacity.
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.