Combustion air damper for two furnaces and two replacement
air dampers (Power Close with Relays)
Hoyme Manufacturing Inc. Special Note: Circuits are colored for
and are not necessarily those found in actual installations. Combustion Air Damper Wires, however, are
colored as shown.
Forced Air Furnaces having a
common combustion air supply duct and two separate replacement fresh air
1. Combustion Air Damper
but having only
combustion air supply duct.* (Damper has two separate operating
2. Two Power
Replacement Air Dampers
and each one inter-connected to its own furnace.
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. Each
Replacement Air Damper opens simultaneously only with the firing of its own furnace but will remain closed regardless of
furnace fan operation. Dampers may be opened on demand by using an optional overriding switch as shown.
1222-ld - Printed in