DOMINATOR INSTALLATION AND OPERATION INSTRUCTIONS
Page 27
Ignition Trial:
1. Once energized, the fl ame sense module (FSM)
initiates 4 second diagnostic cycle before sending
24V ac to the PV terminal and energizing the
ignition transformer.
2. The fl ame failure LED will be lit during the 4 second
diagnostic cycle unless the unit is confi gured for
CSD-1. When the PV terminal energizes, the LED
will turn off. If the ignition trial fails, the LED will
relight.
3. The pilot valve and ignition transformer are
energized for the 10 second ignition trial. The pilot
indicator light illuminates during this time.
4. If the ignition attempt is unsuccessful, the ignition
module will retry in 5 minutes.
5. Since the staging controller remains powered, it will
continue to stage up for as long as the call for heat
exists. The blower, pump and power venter will
remain for as long as a call for heat exists.
6. If the second ignition attempt is unsuccessful the
gas valves will lockout, but the blower, pump and
power venter will remain on. To reset the boiler/water
heater, take one of the following steps:
• Adjust the high limit down below the point at which
the blower shuts down, then reset the limit to its
normal setting.
• Remove power from the boiler/water heater, wait
30 seconds and re-establish power to the unit.
Main Burner:
1. Once the pilot is proved the MV terminal on (FSM)
is energized sending 24V ac to the main gas valve.
2. The main gas valve opens via action of K1.
3. The main burner indicator light illuminates. The PV
terminal remains energized and the pilot indicator
remains on.
Normal Operation
• Staging will be controlled from the staging controller.
• The front control panel separately monitors limit, gas
pressure, water fl ow and air fl ow.
• If staging changes during operation, blowers, pres-
sure switches and gas valves will be switched or
turned off as required.
• Stage 1 will be on fi rst, last and whenever the boiler
operates.
NOTE: For a change from stage 2 to 3 or 3 to 4, 10
second DOM time delays were added to the
pressure switch switching circuits (TDR2 and TDR3).
The time delays provide hold states that allow the
blowers to reach full speed and close the high fi re
pressure switches before they are energized to
confi rm proper air fl ow.
Demand Satisfi ed:
1. Stage switch 1 opens, TDR1 de-energizes.
2. Power is removed from ignition module, blowers and
power venter.
3. All indicators (except power) off.
4. Staging controller initiates a pump purge for 20 or
more seconds, depending on the inlet/outlet
temperatures and
Δ
T setting in the controller. The
pump then shuts off.
Staging Control Alarms:
1. Staging control alarms are visible on the controller's
LCD screen. See the staging control documentation
for details.
2. A powered alarm contact (2A max @ 24 VAC) is
available to provide an audio or visual indication of
faults related only to staging control operation. This
contact is wired to the junction box for optional
remote indication. Refer to the 4 stage wiring
diagram for tie-ins.
High Limit, Low Water Flow, Low Gas Pressure,
High Gas Pressure, Power Venter Interlock Faults
1. All gas valves, the blowers and power venter will
de-energize if either alarm is tripped.
2. The manual reset high limit can be reset through a
knockout accessible in the left side jacket panel.
3. Condition indicators are visible on the control panel.
Low Air (Blocked Flue/Air Inlet)
• One of two pressure switches will monitor the airfl ow
of each blower.
• Air monitoring will begin at prepurge.
• If a low air condition is present on the left side, power
will not be supplied to the module. The blowers will
remain on and the low air indicator will remain on for
as long as a call for heat exists.
• If a low air condition is present on the right side, power
will not be supplied to the right gas valve.
• A low air indicator for each boiler side is visible on the
control panel.
