120Vac vent switch, combustion air and two replacement air dampers(Power Close)(2 furnaces)
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.
Diagram #5A: Two Furnaces having a common combustion air and two replacement air supply ducts together with and exhaust fan controlled by a designated ventilation switch and/or bathroom timer.
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3. 120Vac Ventilation Switch and/or bathroom timer.
4. Adaptor ADP-1101-05A on primary furnace to act as a control center.
1. Replacement Air Dampers are inter-connected to the Combustion Air Damper so that three dampers open during firing of either or both furnaces and close when firing stops.
2. Ventilation Switch and/or bathroom timer turns on exhaust fan, primary furnace fan and opens both HAC dampers simultaneously.
3. Optional switch to each HAC damper allows independent control of each fresh damper.
N.B. Replacement Air Damper is not affected by the ‘Manual’ setting of the furnace fan.
1222-ld - Printed in Canada