120Vac vent switch, combustion air(2 furnaces), replacement air
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 #5B1: Two Furnaces having a common combustion air and two replacement air supply ducts together with an exhaust fan controlled by a designated ventilation switch or bathroom timer.
1. Combustion Air Damper for two furnaces (HOM-0x12-SF2) 2. One HAC-0x11-OPC damper with relay used with adaptor ADP-1101-05A connected to the primary furnace only. 3. One HAC-0x11-OPC damper with relay connected to the secondary furnace.
OPERATION: 1. The combustion air damper opens when either furnace fires. 2. Primary Replacement Air Damper HAC-0x11-OPC opens when primary furnace fires and also opens when ventilation fan is on. 3. Ventilation Switch and/or timer turns on the exhaust fan, the primary furnace fan and opens the primary HAC damper simultaneously. 3. The secondary damper HAC-0x11-OPC opens only when the secondary furnace fires or when an overriding optional switch is used. 4. Optional switch (i.e. toggle switch, timer, de-humidistat) on each HAC damper allows independent control of each damper.
N.B. Replacement Air Dampers are not affected by the ‘Manual’ setting of the furnace fan.
0950 Printed in Canada
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