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SK2018 CHV2-V/P-ECM-001
Control Logic Specifications
Unit Power ON/OFF
a)
The unit is turned ON when any of the fan speed inputs (from thermostat) are ON, or modulating signal input is more
than 2.0 VDC.
b)
The unit is turned OFF only if all of the fan speed inputs (from thermostat) are OFF, or modulating signal input is less than
2.0 VDC.
Alarm Protection and Error Display
a)
If the float switch is open for 5 minutes, then the (NC) voltage-free alarm contact shall be open and the (NO) voltage free
alarm contact shall be closed.
b)
If the float switch is open for 10 minutes, the LED display reports a condensate management failure (see table on the
next page).
Drain Pump Operation
a)
When the unit turns ON:
I.
If Ti1 < 14ºC, the drain pump turns ON.
II.
If 14ºC<=Ti<16ºC, the drain pan keeps original state.
III.
If Ti1 ≥ 16 ºC, the drain pump turns OFF.
b)
When the unit turns OFF and the drain pump is ON:
I.
The drain pump will remain ON for 5 minutes, and then turn OFF.
c)
At any time:
I.
If the float switch is OPEN, the drain pump will turn ON.
II.
If the float switch is OPEN and then CLOSES, the drain pump will remain ON for 5 minutes, and then turn OFF.
Modulating Signal Input
a)
When the “Auto ON/OFF” 230VAC input is ON, the fan motor rpm speed shall be modulated by the “+/-” low voltage
modulating signal input.
b)
The standard configuration is for 0~5VDC modulating signal input.
c)
The optional configuration is for 0~10VDC modulating signal. To set the PCB to the optional configuration, the S1 jumper
must be closed.
Electrical Heater Operation
a)
After unit is turned on, EH relay will be ON when EH signal is power on and EC motor RPM > 300.
b)
If EC motor failure or EC motor RPM is lower than 300RPM, EH relay is opened at once.
Low Temperature Protection of Indoor Coil in Winter
This is frost protection for when the unit is off to prevent water in the coil and room from freezing.
Unit is in Standby Mode
If Ti1
≦
2 ºC for 2 minutes, report error code and Buzzer is beeping for 3 minutes.
