Bard Economizer with exhaust WGEIFM-3C - Manual (Page 16)

Manual 2100-498C
Page
16 of 17
FIGURE 7
CALL FOR BLOWER OPERATION
ECONOMIZER SEQUENCE OF
OPERATION
CONDITION A — COOL OUTDOORS
First stage cooling closes and powers the economizer
dampers to economizer mode and the indoor blower
starts. Mixed Air Sensor senses a mixture of return air
and outdoor air and modulates the dampers accordingly.
Compressor operation is inhibited. (See Figure 7.)
If second stage closes on the thermostat, the dampers
return to the closed or minimum position setting and the
compressor starts for mechanical cooling.