ESI(Ultra) Service Manual
09.2018
8/62 www.ecoer.com
Manufacturer reserves the right to change specifications or designs without notice.
2.2.2 Basic control
Signal Actuator Operation Remark
Y Compressor (INV)
Apply Compressor PI control
to maintain Tes*1
control with inverter protection control.
Y/O Outdoor fan (FAN) Cooling fan control -
O=ON *2 Four way valve (ST1) De-energized -
Y/O Electronic expansion
valve (EEV) 480pls -
2.2.2.1 Cooling control (including cooling oil return)
Signal Actuator Operation Remark
Y Compressor (INV)
Apply Compressor PI control
to maintain Tcs*1 according to
load of the space.
Pressure protection control,
Discharge temperature protection control,
Compressor
control with inverter protection control.
Y/O Outdoor fan (FAN) Heating fan control -
O=OFF Four way valve (ST1) Energized -
Y/O Electronic expansion
valve (EEV)
PI control to maintain
discharge superheat -
2.2.2.2 Heating control (including heating oil return)
Remarks:
1. Tes: Target Te value (Varies depending on mode choice, silent setting, etc.)
Te: Low pressure equivalent saturation temperature(F)
2. SW1_3=OFF(factory), condensing unit uses Y/O/C signal to operate heat pump function.
SW1_3=ON has been set, condensing unit uses Y/C signal to run cooling only.
Remarks:
1. Tcs: Target Tc value (Varies depending on mode choice, silent setting, etc.)
Tc: High pressure equivalent saturation temperature(F)
2.2.2.3 Defrost control
During low ambient temperature heating operation, the outdoor heat exchanger may be covered by
frost resulting in heating capacity reduction. The system will carry out defrost control
automatically if any of the following conditions satisfy.
•TH, the defrost temperature sensor, becomes lower than deicer*1 temperature.
•The high pressure related to ambient temperature or running time is lower than specific value.
Ecoer offers three defrost setting options(n04) designed for different humidity areas. Manual
defrost can be chosen from n08 setting*2. For more details, refer to field setting section.
Defrost will be terminated once the defrost temperature sensor(TH) reaches target value or the
defrost time has exceeded eight minutes.
Remarks
1. This is a specified temperature related to ambient temperature for the system to activate the
defrosting operation.
2. Start-up control is enforced to complete prior to activate the defrost operation.
