Wolf WKG SERIES Service Manual page 38

FULL SIZE GAS CONVECTION OVENS - ELECTRICAL OPERATION
1) R3 normally open (N.O.) contacts
open.
a. Ignition control module de-
energized.
a)
NOTE: This is considered first
stage cooking in the ROAST
AND HOLD cycle.
5. The oven will continue to cycle on the
controlling thermostat until one of the following
occurs: ROAST & HOLD time (R & H cooking)
expires which allows the oven to go into Hold
mode; Power switch (S1) is turned to the OFF
or OVEN COOL position or the doors are
opened.
Timer Cycle (Roast & Hold Cooking)
NOTE: The ROAST & HOLD timer operates
independently of the heating cycle until time expires.
Regulation of the oven temperature is then
transferred to the Hold thermostat until one of the
following occurs: ROAST & HOLD timer is turned
OFF and the function switch (S3) is turned back to
Normal ROAST (normal cooking) or power switch
(S1) is turned to the OFF or OVEN COOL position.
1. With the power switch turned ON, power is
supplied to timer.
2. Set ROAST & HOLD timer to desired time
(Roast & Hold cooking).
NOTE: To Roast then Hold the cooked product at a
fixed temperature, the Roast & Hold timer must be
used and the function switch (S3) must also be set to
Roast & Hold as indicated under step1 conditions for
the Roast & Hold cycle.
A. Contacts 1 & 3 close, timer motor is
energized and timing DOWN begins.
3. Time expires on Roast & Hold timer.
A. Contacts 1 & 3 open, timer motor is de-
energized and timing stops.
B. Contacts 1 & 4 close.
1) If the oven was heating, then the gas
burner and heat light go out; If the
oven was not heating, then the gas
burner and heat light remain out.
2) Hold relay (R2) is energized, R2
contacts change state and the
normally open (N.O.) contacts close.
a. Power to one side of hold
thermostat.
F32700 (February 2006)
nd
Power removed from 2
valve (main) on the gas
valve and gas flow to the
burner stops.
3)
NOTE: This is considered second stage
cooking in the ROAST AND 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
through one set of R4 (N.C.) contacts.
1)
C. Power is applied to one side of the
centrifugal switch on the convection fan
motor through the other set of R4 (N.C.)
contacts.
D. When the convection fan motor reaches
operating speed, the centrifugal switch on
the motor closes.
1)
Page 38 of 64
NOTE: When temperature is above
160°F (±12) the hold thermostat
contacts are open.
Relay R4 is energized, R4 contacts
change state and both sets of
normally closed (N.C.) contacts
transfer to the normally open (N.O.)
position. Power is not transferred until
the hold thermostat contacts close.
Convection fan motor energized (fan
speed low).
Heat relay (R3) is energized.
a. Heat relay (R3) contacts (N.O.)
close and the heating circuit is
powered.
a) Ignition control module is
energized.
b) 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.
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
nd
valve