All installations and services must be performed by qualified service personnel.

“C”

24 VAC common from transformer

“CC”

Compressor Contactor

“CC_COM”

Compressor Contactor Common

“LOW”

Continuous Blower Speed

“HEAT”

Blower heat speed tap

“COOL”

Blower cool speed tap

A. Inputs

Power supplies

Line voltage is applied between the “S1” and “N1” quick connect terminals. 24 VAC Class II Transformer secondary voltage supplied to X and C

Limit switch

The 120 VAC optically isolated limit switch input is connected on pin P2-1 & 9. Refer to the Heat Mode section for the control operation.

Thermostat call for heat “W”

24 VAC thermostat input. A call for heat is recognized when the thermostat connects “W” to “R”. This input has an indicator LED that will light when the control receives a call for heat. Refer to the Heat Mode section for the control operation.

Thermostat call for fan “G”

24 VAC thermostat input. A call for fan is recognized when the thermostat connects “G” to “R”. This input has an indicator LED in that will light when the control receives a call for fan. Refer to the Fan Mode section for the control operation.

B. Outputs

PSC Control

The control shall control a five speed indoor blower motor. Rating shall be 10 FLA, 30 LRA @ 120 VAC. Connections are made via 0.250 x 0.032” male quick connect terminals labeled “HEAT”, “COOL”, and “LOW”. “HEAT” is energized when the heat speed blower is to run. “COOL” is energized when the Cool speed blower is to run. “LOW” is energized during a call for fan is received or a call for dehumidification is received.

Oil Burner

Control

The control provides dedicated contacts to operate the T-T input of an oil primary control. Rating shall be class 2 – 24 VAC pilot duty @ 24 VAC (<200mA).

Power

The switched 120 VAC power from the LIMIT switch passes through the board between Pins 1 & 2 of connector P1.

EAC (electronic air cleaner)

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Thermo Products omd-70 service manual A. Inputs, B. Outputs