Lennox International Inc Zone Control Panel Sequence of Operation continued, Damper Operation

Sequence of Operation (continued)

CONTINUOUS FAN OPERATION

A call for Fan from any zone will initiate the G equipment output terminal. The normally open (NO) damper terminal at all zones not calling for continuous fan will be energized.

DAMPER OPERATION

The “NO” output will be energized and the “NC” output will be de-energized for any zone not calling for heating or cooling while the equipment output is energized and during the damper purge time delay. During equipment operation or during the damper purge time delay, should all zones stop calling for heating or cooling, the damper terminals will remain in the position they were in before all zones stopped calling.

Damper Purge Time Delay

When the Purge/No Purge jumper is at No Purge, the damper purge time delay is 3.5 minutes and begins when the equipment output(s) turn off. NO PURGE is the preferred method of purge control for Lennox furnaces and air conditioners. When the jumper is at Purge, the damper purge time delay is one (1) minute.

Page 9