Vulcan-Hart VC4G Service Manual page 55

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION
3) With the 120VAC output from the
control activated and the centrifugal
switch on the convection fan motor
closed, power is applied to the heat
relay coil (R1).
a. Heat relay coil (R1) is energized,
(R1) contacts (N.O.) close and the
heating circuit is powered.
b. Oven "Heat Light" on the control
comes ON.
c. Ignition control module is
energized.
a)
3. Oven reaches set point temperature.
A. Computer control de-activates the 120VAC
output to heat relay (R1).
1) Heat relay (R1) de-energized and the
normally open (N.O.) contacts OPEN.
a. Power removed from ignition
control module.
a)
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, 2nd valve
(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.
The 2nd valve (main) on the
gas valve is de-energized
and gas flow to the burner
stops.
B. Oven "Heat Light" on the control goes out.
C. Oven "Ready Light" on the control comes
ON.
D. Electronic beeper sounds momentarily.
4. The oven will continue to cycle on the computer
control until the doors are opened or power
switch (S1) is turned to the OFF or COOL DOWN
position.
Temperature and Time Cycle (Cooking)
NOTE: The computers internal COOK timer operates
independently of the heating cycle. Additional time
can be set or the timer can be stopped and restarted
throughout the cooking cycle. Refer to the Instructions
Manual for specific operating instructions of the oven
Computer Control.
Roast and Hold Cycle
NOTE: For a detailed explanation of the ROAST &
HOLD mode, refer to the Instructions Manual as
outlined under SETTING THE OVEN FOR ROAST &
HOLD and ROAST & HOLD OPERATION. In ROAST
& HOLD mode, the operation of the computer control
is identical to the normal Cook Cycle with these
exceptions:
1. Oven ROAST & HOLD light on the control comes
ON.
2. Convection fan speed changes from High to Low.
A. The computer control 5VDC output from
pins C2-2 (-) and C2-8 (+) is de-activated
and SSR1 relay is de-energized.
1)
B. The computer control 5VDC output from
pins C2-1 (-) and C2-8 (+) is activated and
SSR2 relay is energized.
1)
3. At the end of the ROAST time, the electronic
beeper sounds momentarily to indicate the end
of first stage cooking (oven operates normally at
the temperature and time selected until time
expires).
4. The display flashes HOLD as the oven enters
HOLD mode. This is also considered second
stage cooking (oven heating stops but product
continues to cook on residual heat).
A. Convection fan motor is de-energized.
Page 55 of 75
Power (120VAC) is removed from
convection fan motor high speed
terminal.
Power (120VAC) is applied to the
convection fan motor low speed
terminal.
F24682 Rev. D (1016)