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3.
If the same speed must be used for both heating and cool-
ing, remove the undesired motor speed lead from the "Heat"
or "Cool" terminal and connect that lead to the open termi-
nal at "Unused Motor Lead" location. Attach a jumper be-
tween the "Heat" and "Cool" terminals and the remaining
motor speed lead.
Note: For motors with (4) speed leads, it will be necessary to
tape off the terminal of the motor speed lead removed from
the "Heat" or "Cool" terminal with electrical tape since an
open terminal will not be available at the "Unused Motor
Lead" location.
Continuous Fan Operation
A terminal is provided on the electronic fan control located in the
circulating blower compartment for operation of the continuous fan
option. This connection is intended for the low speed motor tap,
and has a lower contact rating (8 amps) than the heat and cool
taps. When the low speed blower lead is connected to this terminal,
this will provide low speed blower operation whenever the other
two speeds (Heat or Cool) are not energized.
Thoroughly check the system after modification to ensure the prop-
er operation of the circulating air blower in all modes of operation.
9. Furnace Maintenance
CAUTION
It is recommended that the furnace be inspected and serviced
on an annual basis (before the heating season) by a qualified
service technician.
10. Sequence of Operation & Diagnostics
The following is the normal operating sequence for the control system.
Cooling (Y) Request:
24 VAC signals applied to Y & G terminals of EFT (electronic fan timer) control.
·
Cool motor speed energized after 5 second Cool Fan On Delay time.
Y & G signals removed from EFT.
·
Cool motor speed de--energized after 90 second Cool Fan Off Delay time.
Circulating Fan (G) Request:
24 VAC signals applied to G terminals of EFT control.
·
motor speed energized without delay.
Heat
G signal removed from EFT.
·
Heat motor speed de--energized without delay.
Heating (W) Request:
24 VAC signals applied to W terminal of EFT control.
·
nducer motor turns on.
I
·
The gas valve solenoid energizes.
·
Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.
·
After the pilot lights, the main burners energize and light.
·
Timed from the opening of the main gas valve, the control will delay 30 seconds before switching the fan to Heat speed.
W signal removed from EFT.
·
The gas valve de--energizes and the main burners go out.
·
The inducer runs at its present speed for a 30 second postpurge period.
·
Timed from the gas valve de--energizing, the Heat fan speed de--energizes after the selected Heat Fan Delay time expires.
Heating Request with Gas Supply Line Shut Off:
24 VAC signals applied to W terminal of EFT control.
·
Inducer motor turns on.
·
The gas valve solenoid energizes.
440 01 1020 02
Separate speed selections for Heat, Cool, and
Continuous Fan
Connect low speed lead from circulating motor to the "Cont." termi-
nal at the electronic fan control. The appropriate motor leads
should already be connected to the "Heat" and "Cool" terminals.
Heating and Continuous Blower Speed the
Same
If it is necessary to operate the heating speed and continuous
blower speed using the same blower speed, connect a jumper be-
tween the "Heat" and "Cont." terminals on the electronic fan con-
trol.
Note: There should be only ONE motor lead going to the "Heat"
and "Cont." terminals.
See "User's Information Manual" and the "Service Manual".
35
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