Home Support Colored Wiring Diagrams #8B - #8D2 #8B7

Colored Wiring Diagram #8B7

Forced Air Furnace with Power Open replacement air duct with a Vent Switch that sends a 24Vac signal to furnace area.
HMI Hoyme Manufacturing Inc. Special Note: Circuits are colored for clarification only and are not necessarily those found in actual installations. Wires of the Combustion Air Damper, however, are colored as shown .
Colored Wiring Diagram #8B7

Diagram #8B7: Forced Air Furnace having a replacement air supply duct together with an exhaust fan controlled by a designated ventilation switch and/or bathroom timer that sends a 24Vac signal to the furnace area.

1. Replacement Air Control Damper, Power Open (HAC-0x10- OPC)
. Ventilation Switch and/or bathroom timer that sends Controlled 24Vac to furnace area.
3. 24Vac Relay Adaptor (ADP-0242-05A)  to function as a control centre.


1. Replacement Air Damper opens when Furnace fires with thermostat signal.
2. Ventilation Switch and/or bathroom timer turns on Ventilation Fan, opens Replacement Air Damper and turns on Furnace Fan simultaneously. Note PC damper is connected to adaptor terminal #4.
3. Optional Switch (i.e. toggle switch) allows full control of the Replacement Air Damper to open Separately proviceded it is a Power Close type Damper.

(For Power Open Damper See Diagram #8A9))

N.B. Replacement Air Damper is not affected by the Manual setting of the furnace fan.

1738-ld Printed in Canada

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