Vulcan-Hart VGCTS16 Service Manual page 19

ROUND COUNTERTOP TILTING BRAISING PANS (16 GALLON) Gas and Electric - ELECTRICAL OPERATION
A. Temperature light goes out.
B. L1 voltage is removed from one side of
contactor coils. Coils are de-energized and
contacts open.
C. Heating elements are then de-energized,
allowing the cooking surface to cool.
5. Control thermostat temperature drops below set
point and contacts (N.O.) close.
A. Cooking surface temperature is maintained
by the heaters cycling with the control
thermostat until the thermostat dial is turned
to the OFF position or the power switch is
turned OFF.
Gas Model
1. Conditions.
A. Unit connected to correct voltage, polarity is
correct and is properly grounded.
B. Power switch OFF.
C. Gas supply valve is ON.
D. Limit switch closed (pan down).
E. Thermostat (potentiometer) dial OFF (0
ohms between wiper arm terminal [red lead]
and one side of the coil [white lead]
clockwise rotation).
F. Temperature controller internal relay
contacts (N.O.) are open.
G. Temperature light off.
H. Ignition light off.
I. High limit thermostat contacts (N.C.) closed.
2. Power switch ON.
A. Temperature controller receives power from
L1 (120VAC) and NEUTRAL, and is
energized through L1 and L2 terminals on
controller.
B. L1 (120VAC) to the common side of internal
relay contacts.
C. NEUTRAL to one side of the temperature
light and step-down transformer (120VAC to
24VAC).
3. Turn the thermostat (potentiometer) dial until a
call for heat is made.
A. Internal relay on temperature controller is
energized, and the (N.O.) contacts close.
B. Power from L1 (120VAC) is then supplied to
the other side of the temperature light and
the step-down transformer (120VAC to
24VAC).
1)
4. Ignition module is energized (24VAC) through
the high limit (N.C.) contacts and ground.
A. Ignition trial cycle begins.
1)
2)
3)
4)
5. Temperature controller reaches set point
temperature.
A. Internal relay on temperature controller is
de-energized and the contacts open.
B. Temperature light goes out.
C. Power is removed from the ignition control
module.
1)
2)
3)
6. Temperature controller drops below set point.
A. Cooking surface temperature is maintained
by the gas burner cycling with the
temperature controller until the
potentiometer dial is turned to the OFF
position, or the power switch is turned OFF.
Page 19 of 26
Temperature light comes on, and the
step-down transformer is energized.
Module delays energizing HSI for a 5-
second purge time to allow any
residual gas to dissipate. After purge
time elapses, HSI begins a 3-second
heat up time.
After HSI heat up time elapses, the gas
solenoid valve opens to supply gas to
the hot ignitor and the ignition light
comes on.
When burner lights, flame sense probe
detects flame, HSI de-energizes after
an 8.5-second ignition trial time, gas
solenoid valve stays open and heating
begins.
If burner plate is not detected after
ignition trial time elapses, then the
ignition control module locks out power
to the gas solenoid valve. The module
remains locked out until the thermostat
(potentiometer) dial is turned to OFF
then back to a set point temperature, or
the power switch is turned OFF then
back ON again.
Gas solenoid valve closes.
Burner shuts off.
Ignition light goes out.
F24643 (1217)