Timer, vent switch and replacement air opens during firing
HMI Hoyme Manufacturing Inc. Special Note: Circuits are colored for clarification only and are not necessarily those found in actual installations.
Diagram #10: Forced Air Furnace having a replacement air supply duct together with an exhaust fan controlled by a designated ventilation switch and/or a bathroom timer and an interval timer. Thermostat also opens the replacement air supply damper during firing.
2. Ventilation Switch and/or bathroom timer with Controlled and Regular 120Vac, 3-Wire supply to furnace area.
3. Relay Adaptor with Interval Timer (TMADP-1102-TPX) as control centre.
1. Replacement Air Damper opens during furnace firing.
2. Ventilation Switch and/or bathroom timer turns on Ventilation Fan, opens Replacement Air Damper and turns on Furnace Fan simultaneously.
3. Interval Timer, with minimum or multiple consecutive settings of 15 minutes each, can turn on Ventilation Fan, open Replacement Air Damper and turn on Furnace Fan simultaneously.
4. Opt. Switch (i.e. toggle switch, timer, de-humidistat) allows full control of the Replacement Air Damper to open provided it is a PC type.
N.B. Replacement Air Damper is not affected by the ‘Manual’ setting of the furnace fan.
1222-ld - Printed in Canada
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