7.
Cooking compartment pressure switch closes as
boiler steam pressure reaches 3 PSI
(approximately 14 minutes).
•
Green READY light turns ON.
NOTE:
If a cooking timer is set immediately after the
green READY light comes on, a loud clanking sound
will be heard (oil caning) and the ready light will flash
for several seconds. This condition is caused by the
manifold pressure being on the fringe of the pressure
switch set point. When a cook timer is set, the
compartment steam solenoid valve opens causing the
manifold steam pressure to drop, slightly below the
pressure switch set point. At the same time, steam
pressure is still increasing in the boiler. This opposing
condition causes a pressure bounce to occur but after
the steam pressure passes approximately 4 psi this
condition subsides. Under normal steam cycling
pressures, this condition will not be seen.
8.
Boiler steam pressure reaches upper limit set
point of 10 PSI (approximately 15 minutes).
•
Cycling pressure switch opens, main gas
solenoid valve de-energizes, gas flow shuts
off and burners go out.
NOTE:
Steam should not be seen entering either
compartment until a cook time is set. This energizes
the steam solenoid valve of the cooking compartment
to allow steam flow.
9.
Boiler steam pressure drops below lower limit set
point of 8 PSI and the cycling pressure switch
closes.
•
Boiler steam pressure is maintained by the
cycling of the pressure switch between the
upper and lower set point limits. The cycling
pressure switch continues to energize and
de-energize the main gas solenoid valve
starting and stopping the flow of gas, which
in turn, cycles the burners on and off. This
sequence continues until one of the
following occurs:
•
Boiler pressurizes to 15 PSI, causing
the high limit pressure switch to open.
At that time, the auxiliary gas valve de-
energizes, shutting off the gas flow to
the burners and the high limit failure
light will come on. This light will stay lit
until the pressure drops below the
lower limit set point of 6 PSI and the
manual re-set switch is pressed.
•
Boiler water level drops below the
LLCO probes for the water level and
the auxiliary low level cut-off controls
which then de-energizes the LLCO
relays, changing the contact state of
LLCO-2 (N.O.) back to open. This de-
energize the main and auxiliary gas
solenoid valves. The gas solenoid
valves will remain off and the low water
level light will come on and stay lit until
the water level rises above the LLCO
probes and the manual re-set switch is
pressed.
Cook Cycle
1.
A cook cycle should not be started, until the initial
fill and preheat is completed, in order for the
boiler steam pressure to be within operational
limits.
•
Green READY light is ON.
•
Product is inserted into steamer.
•
Door is closed.
•
Timer is dialed on timer.
2.
Contacts 1/3 of cook timer close.
•
Green READY light turns OFF.
•
Red COOKING turns ON.
•
Timer motor is energized.
•
Compartment steam solenoid valve
energized and steam begins to enter the
compartment.
NOTE:
Burners will re-light after the boiler pressure
drops below the low pressure set point limit (8 psi) and
will stay on until the high pressure set point (10 psi) is
reached. As long as steam pressure is within limits,
even while cooking, burners can go off. The boiler is
able to re-pressurize to the upper set point limit even
with both compartments in cook mode.
NOTE:
The CWC thermostat remains closed and
CWC solenoid stays energized while cooking. If main
water is shut off after boiler fill, then no cold water is
present to condense steam/hot water and steam
vapors exit the floor drain.
3.
Time expires on timer.
•
Timer contacts 1/3 open.
•
Steam solenoid valve de-energized,
stopping the flow steam into compartment.
•
Red COOKING light turns OFF.
•
Timer contacts 4/1 close and energize
buzzer until manually turned off.
VSX BOILER BASE SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION
Page 37 of 82
F24627 (0916)
