Home Support Colored Wiring Diagrams #10 - #12D1 #12B3

Colored Wiring Diagram #12B3

Two Vent switches and interlocking replacement air - Power Open

HMI Hoyme Manufacturing Inc. Special Note: Circuits are colored for clarification only and are not necessarily those found in actual installations.  

Diagram #12B3: Forced Air Furnace having a replacement air supply duct together with two designated ventilation switches and/or bathroom timers to turn on an exhaust fan INTERLOCKED to a replacement Power Open air control damper.

1. Replacement Power Open Air Damper and End Switch (HAC-0x10-SPO). 

2. Ventilation Switches and/or bathroom timers with 3-Wire 120Vac supply to furnace area. 

3. Relay Adaptors (ADP-1102-TPX) function as a control centres.


1. Furnace fires with thermostat signal. 

2. Ventilation Switch and/or bathroom timer opens the Replacement Air Damper. After Damper proves to be open (INTERLOCKED), the exhaust Fan and Furnace Fan will turn on.

N.B. Replacement Air Damper is not affected by the ‘Manual’ setting of the furnace fan. 
Also does not interfere with the Air Conditioner.

1737-ld - Printed in Canada

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Last Updated (Monday, 11 September 2017 13:35)