•
Water Level Control (WLC) is powered ON.
•
HL relay is energized, HL-3 (N.O.)
contacts close and HL LED turns ON.
•
The IL relay remains de-energized,
leaving the ILR-1 (N.O.) and ILR-2
(N.C.) contacts in their shelf state.
•
Auxiliary low water level cut-off control is
powered, LLCO-2 (N.O.) contacts remain
open.
•
With the HL-3 and ILR-2 contacts closed,
the fill solenoid is energized and water boiler
begins filling.
•
Blowdown solenoid valve is energized and
closes.
•
Ignition module begins sparking to light pilot
after a 3-second delay.
•
If pilot ignition is established (pilot lit)
then a micro amp flame sense current
is sent back to the ignition control
module through the ignition cable.
Sparking stops, pilot remains lit and is
ready to ignite burners.
•
If pilot ignition is not established after
90 seconds, sparking stops and the
ignition control module locks out power
to the combination gas valve (pilot
valve and main valve remain closed).
The module remains locked out until
the reset switch on the ignition control
module box is switched to off then on
to re-start the ignition trial cycle.
NOTE:
If the modules reset switch is in the OFF
position, no sparking will occur or if it’s turned off while
in READY or COOK mode then pilot and burners will
go out and not re-ignite upon call for heat by the
cycling pressure switch.
3.
Water level reaches LLCO probe for the water
level control and to the auxiliary LLCO probe for
the auxiliary low level cut-off control.
•
Power to terminal 9 on the water level
control.
•
LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LED turns ON.
•
Power to terminal LLCO on the auxiliary low
water level cut-off control.
•
LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LED turns ON.
NOTE:
LLCO relays will remain energized and LLCO
LED’S will remain ON until the water level drops below
the LLCO probes or the power switch is turned OFF.
4.
Water reaches LL probe.
•
Power to terminal 2 on the water level
control is present but no switching occurs.
5.
Water reaches HL probe (approximately 4-11
minutes).
•
Power to terminal 6 on water level control.
•
The IL relay is energized, changing the
state of ILR-1 (N.O.) and ILR-2 (N.C.)
contacts. The IL relay will remain
energized through the alternate
latching path of ILR-1 contacts until the
water level recedes below the LL
probe.
•
With ILR-2 contacts open, HL relay is
de-energized, HL-3 (N.O.) contacts
open and HL LED turns OFF.
•
Water fill solenoid is de-energized.
6.
Manual re-set switch is pressed, energizing the
coils on the high limit and low water relays.
•
Contacts 1 & 9 on the high pressure relay
change state and lock from N.C. to N.O. and
turn off the high pressure indicator light.
Concurrently, contacts 1 & 9 on the low
water relay change state and lock from N.C.
to N.O. and turn off the low water indicator
light.
•
Contacts 5 & 9 on the high pressure relay
change state and lock from N.O. to N.C.,
supplying power (NEUTRAL) to one side of
the auxiliary gas solenoid valve.
Concurrently, contacts 5 & 9 on the low
water relay change state and lock from N.O.
to N.C., supplying power (L1) to the other
side of the auxiliary gas solenoid valve.
NOTE:
For both relays to energize, the high pressure
switch must be closed and the water level in the boiler
must be above the LLCO probes in order for LLCO-2
(N.O.) contacts to close.
•
Auxiliary gas solenoid valve is energized
and opens to allow gas flow.
•
As long as the ignition control module is
sensing a pilot flame, the internal main valve
(MV) contacts close (N.O.) on the ignition
control module. The main gas valve is
energized and gas begins flowing.
•
Burners light and boiler begins to heat up.
VSX BOILER BASE SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION
F24627 (0916)
Page 36 of 82
