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10. Sequence of Operation
& Diagnostics
The following
is the normal
operating
sequence
for the control
system.
Cooling (¥) 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.
•
Heat motor speed energized
without delay.
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.
•
Inducer
motor
turns on.
•
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.
•
Following
a 3 second
prepurge
delay, the pilot valve
opens
and the ignitor
begins
to warm
up.
•
The ignitor
glows
red-hot
for 30 seconds,
then turns
off.
•
The igniter
stays
off for 25 seconds,
then
begins
to warm-up
again.
•
The igniter
glows
red-hot
for 30 seconds,
then turns
off.
•
The pilot valve
closes
3 seconds
after the igniter
de-energizes.
•
The inducer
de-energizes
5 seconds
after the pilot valve
closes.
•
The SmartValve
proceeds
to soft lockout
and flashes
error code 6.
•
The control
exits soft lockout
after 5 minutes
and begins
another
ignition
sequence.
44001 102004
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