Wolf WKG SERIES Service Manual page 40

FULL SIZE GAS CONVECTION OVENS - ELECTRICAL OPERATION
a. Motor speed relay (R1) is
energized through hold relay
(R2) normally closed contacts
(N.C.). Relay contacts (R1)
change state and the normally
open (N.O.) set of contacts close.
a)
b)
c)
3) Power is also connected back through
a second set of contacts on the power
switch (S1) to terminal 8 on the
temperature control board.
a. Solid state temperature control
energized. If the oven
temperature is below set point,
the temperature control will
energize its internal relay. The
normally open (N.O.) contacts
close and apply power to the
following components:
a)
b)
c)
d)
F32700 (February 2006)
Power is connected through
the function switch (S3)
contacts and convection fan
motor is energized (fan
speed hi).
When the convection fan
motor reaches operating
speed, the centrifugal switch
(N.O.) on the motor closes.
Power to normally open
(N.O.) side of internal relay
contacts (terminal 7) on the
temperature control board.
Heat light (clear) comes ON.
Power is connected through
the centrifugal switch
contacts on the convection
fan motor, heat relay (R3) is
energized, (R3) contacts
(N.O.) close and the heating
circuit is powered.
Ignition control 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
IGNITION light stays out
and burner remains lit.
4. Oven reaches set temperature.
A. Temperature control de-energizes internal
relay and the normally open (N.O.)
contacts OPEN.
1)
2)
5. The oven will continue to cycle on the
temperature control until the doors are opened
or power switch (S1) is turned to the OFF or
OVEN COOL position.
Timer Cycle (Normal Roast Cooking)
NOTE: The ROAST timer (normal cooking) operates
independently of the heating cycle. Additional time
can be set or the timer can be turned OFF
throughout the cooking cycle.
1. With the power switch turned ON, power is
supplied to timer.
A. Set ROAST timer to desired time (normal
cooking).
B. Contacts 1 & 3 close, timer motor is
energized and timing DOWN begins.
2. Time expires on ROAST timer (normal cooking).
A. Contacts 1 & 3 open, timer motor is de-
energized and timing stops.
B. Contacts 1 & 4 close.
1)
NOTE: The buzzer continues to sound until
the timer dial is set to the OFF position or
additional time is set.
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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.
Heat light goes out.
Power removed from heat relay (R3).
a. R3 normally open (N.O.)
contacts OPEN.
a) Power removed from 2
valve (main) on the gas
valve and gas flow to the
burner stops.
Buzzer energized and sounds.
nd
valve
nd