Combustion air damper for two furnaces and replacement air damper (Power Close)
HMI Hoyme Manufacturing Inc. Special Note: Circuits are colored for clarification only and are not necessarily those found in actual installations. Combustion Air Damper Wires, however, are colored as shown.
Diagram #2A: Two Forced Air Furnaces having a common combustion air supply duct and a common replacement fresh air supply duct.
1. Combustion Air Damper for two appliances *(HOM-0x12-SF2)* but having only one combustion air supply duct. *(Damper has two separate operating circuits)*.
OPERATION: Combustion Air Damper is interlocked to both appliances so that the damper proves to be open to supply fresh air for combustion when either one or the other or both furnaces are firing. Replacement Air Damper opens simultaneously with the HOM damper or by an optional switch as shown.
1222-ld - Printed in Canada