S9200U1000 UNIVERSAL HOT SURFACE IGNITION INTEGRATED FURNACE CONTROL
69-2075EF—01
14
Rollout Circuit Operation (during Heat
cycle)
If the rollout circuit opens during a heating cycle:
— The gas valve is immediately de-energized.
— The inducer is energized.
— The circulator is energized at heat speed.
— An LED error code is flashed, which indicates the
rollout circuit has opened. See Table 12 on
page 20.
— An EnviraCOM™ alarm is active and sent on the
bus. See Table 14 on page 22.
— Thermostat requests for heat are ignored.
The S9200U1000 remains in this state until the rollout
circuit closes.
Once the rollout circuit has closed:
— The inducer is de-energized after the Postpurge
Period.
— The circulator is de-energized after the selected
heat off delay.
— The LED continues to flash the rollout switch error
code.
— Thermostat requests for heat are still ignored.
The S9200U1000 remains in this state until power is
cycled, at which time the S9200U1000 resumes normal
operation.
Limit Switch Circuit Operation (during
Heat cycle)
If the limit circuit opens during a heating cycle:
— The gas valve is immediately de-energized and
the inducer is de-energized after the Postpurge
Period.
— The LED flashes an error code, indicating the limit
circuit is open. See Table 12 on page 20.
— An EnviraCOM™ alarm is active and sent on the
bus. See Table 14 on page 22.
— The circulator is immediately energized or
remains energized at the heat speed.
— If the limit switch opens during the Trial for Ignition
period, the trial is treated as a failed one (next trial
is retry).
— If the limit switch opens in run mode, the
sequence is treated as a failed one (next trial is
recycle).
The S9200U1000 remains in this state until the limit circuit
closes. Once the limit circuit closes:
— If the limit circuit was open for less than three min-
utes, a new ignition sequence is started and the
circulator will remain energized for the selected
fan off delay. If the burner is lit before expiration of
the selected fan off delay, the fan off timing is
stopped and the circulator remains energized.
— If the limit circuit was open for longer than three
minutes, the circulator will remain energized at
heat speed for the selected heat fan off delay, and
the S9200U1000 will proceed to Soft Lockout,
where it will remain for the Auto Restart Delay or
until a thermostat reset is detected.
Pressure Switch Operation (during Heat
cycle)
— If a call for heat is initiated and the pressure switch
is closed before the ignition sequence has begun,
the S9200U1000 will wait five seconds and flash
an LED error code, which indicates the pressure
switch is stuck closed. An EnviraCOM™ alarm is
active and sent on the bus (see Table 14 on
page 22). As soon as the pressure switch opens
the error code clears and the ignition sequence
proceeds as normal.
— If the ignition sequence has begun and the pres-
sure switch fails to close within 150 seconds of
energizing the inducer, the S9200U1000 de-ener-
gizes the inducer, starts flashing the “Pressure
Switch Failed Open” error code and returns to Idle
Mode for five minutes before beginning the igni-
tion sequence again (see Table 12 on page 20).
An EnviraCOM™ alarm is active and sent on the
bus (see Table 14 on page 22).
— This process continues indefinitely and an error
code indicating a failed pressure switch flashes
until the pressure switch finally closes or the call
for heat ends.
— If the pressure switch opens during Prepurge or
Igniter Warm-up, the S9200U1000 will de-ener-
gize the igniter and leave the inducer energized
for a maximum of 60 seconds to try and re-close
the switch. If the switch closes, the ignition cycle
will resume from the beginning of Prepurge again.
If the switch does not re-close, the S9200U1000
behaves as if the pressure switch had not closed
after the inducer turned on.
— If the pressure switch opens for longer than two
seconds during Trial for Ignition or opens for
longer than 50 milliseconds during normal fire
operation and flame is lost, the S9200U1000 pro-
ceeds to Interpurge before attempting the ignition
sequence again.
An error code indicating the pressure switch failed
open flashes until the burner is lit again or the heat
demand is removed (see Table 12 on page 20).
An EnviraCOM™ alarm is active and sent on the
bus (see Table 14 on page 22.)
— If the pressure switch opens for longer than two
seconds during Interpurge, the S9200U1000 pro-
ceeds to the “Wait for Pressure Switch to Close”
state.
Hot Surface Igniter (HSI) Control
The Hot Surface Igniter is directly powered by line voltage
input. The HSI warm-up time is shorter for the first ignition
trial when using the 17/27 second warm-up time setting
and longer for subsequent trials. See Table 10 on
page 12.
Normal Cooling Mode
A call for cooling is signaled by:
— The shorting of R/2 to Y.
— The shorting of R/2 to Y and G simultaneously.
— An EnviraCOM™ cool demand of any stage.
Refer to Fig. 10 on page 18 for the control sequence
diagram.
Fan Mode
In fan mode operation:
— If the S9200U1000 is not currently servicing
another circulator request, the circulator energizes
at the heat speed when R/2 is shorted to G and
de-energizes when the request is removed. G
functionality can also be received as an Envira-
COM™ message.
— If the S9200U1000 is servicing a fan request and
a call for cool occurs, the circulator switches to the
cool speed after the Cool Fan On Delay.
— If the S9200U1000 is servicing a fan request and
a call for heat occurs, the circulator remains ener-
gized at the heat speed.
