Friedrich 9, 000 BTU'S service manual Cool mode control features for cool with electric heat units

vpak electronic control board and wall thermostat sequence of operation (Continued)

cool mode control features for cool with electric heat units

Reversing valve:

Always de-energizedwhen “Cool” switch is selected on thermostat.

Compressor operation:

If ambient indoor temperature is above set point temperature depending on t-stat differential and the compressor is not time delayed, turn on compressor. If ambient indoor temperature is below set point depending on t-stat differential, turn off the compressor.

Compressor time delay:

The time delay feature is de-energizedfor a period of time that varies randomly from 180 to

240 seconds. Compressor time delay is initiated every time the compressor is “off” due to:

(1)Satisfying the temperature set point,

(2)Changing mode to fan only

(3 )Turning the unit off.

(4)Control is first energized or when power is restored after failure Note: Time delay is disabled during Test Mode.

Indoor coil frost protection (Error Code 07):

While in cool mode: If the indoor coil frost protection sensor reads 30°F for 2 minutes continu- ously, turn off the compressor, but continue fan operation. While the compressor is out and the fan is running: when the indoor coil frost protection sensor reaches 45°F, turn on the compres- sor. However, the compressor must still wait a standard time of 180 to 240 seconds. While 07 flash, heat operation is disabled.

Fan delay:

This is only for fan ‘cycle’ mode and not for fan ‘continuous’ mode. When unit cycles cool- ing ON – start the fan 5 seconds EARLY. When unit cycles cooling OFF – DELAY the fan off for 30 seconds. Note: the fan delay is disabled during Test Mode.

electric heat mode control features for cool with electric heat units

Reversing valve: Always de-energized when “Heat” button is pushed.

Compressor operation: Compressor does not operate in this mode.

Electric heat operation: If temp is below set point, depending on t-stat differential, turn on electric heat. If Ambient is above set point depending on t-stat differential, turn off the electric

heat.

Fan delay: This is only for fan ‘cycle’ mode and not for fan ‘continuous’ mode. When unit cycles heating ON – start the fan 5 seconds EARLY. When unit cycles heating OFF – DELAY the fan off for 15 seconds. Note: the fan delay is disabled during Test Mode.

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