Vulcan-Hart SG4D Service Manual page 46

SG4 & SG6 Series Full Size Gas Convection Ovens - ELECTRICAL OPERATION
C. 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 (Normal Cooking)
The computer's 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 Installation & Operation Manual for
specific operation instructions of the oven computer
control.
Function Switch SG4C/SG6C - Selects the cooking
mode of the oven between Cook or Roast and Hold.
Is used in conjunction with the Roast and Hold timer
during Roast and Hold cooking. The selected mode
also determines the fixed blower speed: HI for Cook
and LO for Roast and Hold. If Roast and Hold is
selected, when the Roast (then hold) time expires, the
oven heating stops and the oven enters the hold
mode. Once the even cavity temperature drops to
150°F, the heat comes back on and the oven cycles
at this temperature to hold the cooked product.
Roast and Hold Cycle
For a detailed explanation of the Roast and Hold
mode, refer to the instructions manual.
In the Roast and Hold mode, the operation of the
computer control is identical to the normal cook cycle,
with these exceptions:
1. Oven Roast and Hold light on the control comes
ON.
2. Convection fan speed changes from HI to LO.
A. The computer control 5 VDC output from
pins C2-2 (-) and C2-8 (=) is deactivated and
SSR1 relay is de-energized.
F35626 Rev. B (1118)
1)
B. The computer control 5 VDC output from
pins C2-1 (-) and C2-8 (+) is activated and
SSR2 relay is energized.
1)
3. At the end of the cook time, the electronic beeper
sounds momentarily to indicate the end of the
first stage cooking (oven operates normally at the
temperature and time selected until time
expires).
4. The display flashes HOLD as the oven enters the
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.
B. Oven fan cycles with the output of the
heating system. Anytime the system calls
for heat, the fan must be running. After the
oven has reached the 150°F set
temperature, the heat and fan are
deenergized.
5. After the oven temperature drops below 150°F,
the heat comes back on and cycles as needed to
maintain the hold temperature of 150°F.
A. Convection fan motor energized.
6. The oven continues to cycle in this manner until
one of he following occurs:
A. A. The cook and hold mode is turned OFF.
B. Power switch (S1) is turned to the OFF or
COOL DOWN position.
Page 46 of 56
Power (120 VAC) is removed from
convection fan motor high speed
terminal.
Power (120 VAC) is applied to the
convection fan motor low speed
terminal.