Manufacturer reserves the right to change specifications or designs without notice.
ESI (Ultra) Service Manual
ON DIP
1 2 3 4
2.2.2
Basic control
2.2.2.1 Normal control
Input
Signal Actuator Cooling control (including
cooling oil return)
Heating control (including
heating oil return)
Y Compressor (INV) Apply Compressor PI control to
maintain Tes*1
Apply Compressor PI control to
maintain Tcs*1
Y / O*2 Outdoor fan (FAN) Cooling fan control Heating fan control
*2
Reversing valve (ST1) De-energized
Y / O*2
Electronic expansion
valve (EEV)
480pls
PI control to maintain discharge
superheat (DSH)
Remarks:
1. Tes: Target Te value (Varies depending on the load of space, mode choice, silent setting, etc.)
Te: Low pressure equivalent saturation temperature (°F)
Tcs: Target Tc value (Varies depending on the load of space, mode choice, silent setting, etc.)
Tc: High pressure equivalent saturation temperature (°F)
2. SW1_3=OFF (factory), condensing unit uses Y/C/O (O for cooling) signal to operate heat pump.
SW1_3=ON has been set, condensing unit uses Y/C signal to run coolingonly.
SW1 on ODU PCB
SW1_3: AC / HP
Switch
2.2.2.2 Defrost control
This system carries out demand defrost control if any one of the following conditions satisfy.
I. The calculated temperature difference between ambient temperature (TA) and defrost
temperature (TH) is called Delta T. After Delta T is achieved and continues for 5 minutes.
a) 41°F < TA < 59°F, TH ≤ 30°F, Delta T = 18°F
b) 19°F ≤ TA ≤ 41°F, TH ≤ 30°F, Delta T = 12~18°F
c) TA <19°F, TH < 9°F, accumulative compressor run time ≥ 80 minutes
TH backup running, TA < 59°F and LP ≤ 90psi, accumulative compressor run time ≥ 60 minutes
II. After “Minimum Run Time” (MRT) is achieved.
a) MRT is 3.5 hours when TA <23°F
b) MRT is 2 hours when 23°F ≤ TA < 43°F
III. The high pressure drops below 245psi for 20 minutes when 14°F ≤ TA ≤28°F.
IV. Manual defrosting can be chosen from n08 setting.
Start-up control is enforced to complete, then wait another 5 minutes to activate the defrost operation.
Defrost will be terminated once defrost temperature sensor (TH) reaches 64°F for 60 seconds or the
defrost time has exceeded 8 minutes. Defrost mode setting (n04) offers termination options for
different geographical conditions.
a) Defrost in heavy snow area will extend defrost for 60 seconds, but reduce the heating time to execute
more defrost operations.
b) Defrost in light snow area will reduce defrost for 30seconds.
