Oven Cool Cycle (Solid State Temperature Control) - Wolf WKG SERIES Service Manual

FULL SIZE GAS CONVECTION OVENS - ELECTRICAL OPERATION
a. Power to one side of hold
thermostat.
NOTE: When temperature is above
160°F (±12) the hold thermostat
contacts are open.
3) Motor speed relay (R1) de-energized,
(R1) contacts change state and the
normally open (N.O.) contacts OPEN.
a. Convection fan motor stops and
centrifugal switch (N.O.) on
motor OPENS.
a)
NOTE: This is considered
second stage cooking in the
ROAST & HOLD cycle where the
stored heat in the oven continues
to cook the product.
4. Oven temperature falls below 160°F (±12) and
hold thermostat contacts close.
A. Heat light comes ON.
B. Motor speed relay (R1) is energized, (R1)
contacts change state and the normally
open (N.O.) contacts CLOSE.
1) Convection fan motor energized (fan
speed low).
C. Power is also applied to one side of the
centrifugal switch on the convection fan
motor through the temperature control
internal relay (N.O.) contacts.
D. When the convection fan motor reaches
operating speed, the centrifugal switch on
the motor closes.
1) Heat relay (R3) is energized.
a. Heat relay (R3) contacts (N.O.)
close and the heating circuit is
powered.
a)
b)
Heat relay (R3) de-
energized, relay (R3)
contacts open and oven
heating stops.
Ignition module is
energized.
No ignition light (red) comes
ON, module performs a self
diagnostic test for 4
seconds, 2nd valve (main)
on the gas valve is
energized. Gas starts to flow
to the burner, sparking
begins, the NO IGNITION
light goes out and burner
lights. Sparking continues
for up to 7 seconds or until a
flame is established. If a
flame is SENSED, the NO
5. Oven reaches the FIXED hold temperature and
hold thermostat opens.
A. Heat light goes out.
B. Power removed from heat relay (R3) and
the contacts open (N.O.).
1)
C. Power is also removed from motor speed
relay (R1).
1)
6. The oven will continue to cycle on the hold
thermostat until the ROAST & HOLD timer is
turned to the OFF position and the function
switch (S3) is change back to ROAST (normal
cooking) or the power switch (S1) is turned to
the OFF or OVEN COOL position.
Oven Cool Cycle (Solid State Temperature
Control)
NOTE: The electrical sequence of operation for the
OVEN COOL cycle is written for ovens with the
ROAST & HOLD option.
1. Conditions.
A. Oven is ON.
B. Oven cavity temperature needs to be
lowered.
C. Doors are open.
1)
D. Roast and Hold timer in the OFF position.
E. Roast timer (normal cooking) in the OFF
position.
F. Function switch (S3) set to either Normal
ROAST cycle or ROAST & HOLD cycle.
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IGNITION light stays out
and burner remains lit.
If a flame is not SENSED
after 7 seconds of sparking,
the NO IGNITION light
comes back on, 2
(main) on the gas valve is
de-energized and gas flow
to the burner stops. Ignition
trial cycle repeats after a 15
second purge between
cycles for two additional
tries before locking out. To
reset after a lockout, turn
power switch (S1) OFF then
ON.
Ignition control module de-energized.
a. Power removed from 2
(main) on the gas valve and gas
flow to the burner stops.
Convection fan motor de-energized
and fan stops rotating.
Door switch contacts OPEN.
F32700 (February 2006)
nd
valve
nd
valve