Sequence Of Operation - Vulcan-Hart VE30 Service Manual

SEQUENCE OF OPERATION

Refer to schematic diagram AI1376 for the electrical
sequence of operation. Manual pan lift is the
standard configuration.
Heating
1. Conditions.
A. Braising pan connected to correct supply
voltage and is properly grounded.
1) 240-480/120VAC transformer
energized.
2) Temperature controller energized.
3) 120/24VAC transformer energized.
B. Temperature dial at lowest setting
(potentiometer fully CCW).
NOTE: Temperature controller internal relay
contacts remain open (N.O.).
C. Pan temperature is below 200/F.
D. On/off switch off.
E. Pan position/down limit switch N.O.
contacts closed (pan down).
F. High limit thermostat closed.
2. Turn on/off switch on.
A. Indicator light (amber) comes on.
3. Set the temperature dial to call for heat.
A. Internal relay on temperature controller is
energized and HT.0/HT.1 N.O. contacts
close.
1) Heat light (red) comes on.
2) K3 heat relay coil energized and K3
4/7 N.O. contacts close.
a. Contactor coils C1, C2 and C3
(VE40 only) energized and
heating elements are powered.
NOTE: If pan is raised 2.25" to 2.50"
at the rear, pan position/down limit
switch N.O. contacts will open and de-
energize K3 heat relay coil.
4. Braising pan reaches set point temperature.
A. Internal relay on temperature controller is
de-energized and HT.0/HT.1 N.O. contacts
open.
1) Heat light (red) goes out.
2) K3 heat relay coil de-energized and
K3 4/7 N.O. contacts open.
ELECTRIC BRAISING PANS - ELECTRICAL OPERATION
Page 23 of 32
a. Contactor coils C1, C2 and C3
(VE40 only) are de-energized
and power is removed from
heating elements.
5. Braising pan will continue to cycle with the
temperature controller until the pan is raised or
the on/off switch is turned off.
Motorized Pan Lift (Option)
Refer to the dashed line sections labeled
MOTORIZED LIFT OPTION on the schematic
diagram for the integration of the motorized pan lift
components into the sequence of operation.
1. Conditions.
A. Braising pan connected to correct supply
voltage and is properly grounded.
1) 240-480/120VAC transformer
energized.
2) 120/24VAC transformer energized.
B. On/off switch off.
C. Lift control switch off (center position).
D. Lid switch N.O. contacts closed (lid
opened).
E. Up limit switch N.C. contacts closed (pan
position is less than full tilt).
F. Pan position/down limit switch N.O.
contacts closed; and N.C. contacts open
(pan down).
NOTE: The pan position/down limit switch are
contained in the same switch body. Both sets of
DPST contacts are utilized.
2. Turn on/off switch on.
A. Indicator light (amber) comes on.
NOTE: If temperature dial is set to call for heat,
contactors C1, C2 and C3 (VE40 only) are
energized thru heat relay K3 4/7 N.O. contacts.
3. Operate the lift control switch to raise the pan
(momentary on - raise).
A. K1 relay coil is energized thru the up limit
switch N.C contacts.
1) K1 4/7 N.O. contacts close.
2) K1 9/6 N.O. contacts close.
3) K1 8/5 N.O. contacts close.
B. 120VAC to DC motor controller thru K1 4/7
N.O. contacts.
1) 90VDC output is activated at terminals
A + (positive) and A - (negative). DC
lift motor powered thru K1 9/6 N.O.
contacts, K1 8/5 N.O. contacts and
pan raises.
F35410 (May 2003)