Sequence Of Operation; Solid State Or Computer, Cooking Control - Vulcan-Hart GRC35 Service Manual

GR SERIES GAS FRYERS - ELECTRICAL OPERATION

SEQUENCE OF OPERATION

Solid State or Computer, Cooking Control

Refer to schematic diagram 7411 for Cooking Control
operation.
FRY CYCLE - LIQUID FRYING OIL
If using solid shortening, the control should be
programmed to use the MELT CYCLE. In the MELT
CYCLE, the control will "cycle" the heat ON/OFF in short
intervals. This will gradually heat and liquefy the
shortening until it reaches a temperature of 135°F. Melt
cycle default times are:
• Liquid (CY L) = 16 sec on, 18 sec off
• Solid (CY S) = 8 sec on, 26 sec off
• No melt (CY 0) = 100% on.
The control then resumes normal operation as
described in this sequence.
1. Conditions.
A. Fryer battery connected to correct supply voltage
and properly grounded.
NOTE: Separate connections are required for the
fryer controls and the filtering system controls.
B. Gas supply valve on and gas combination valve
"knob" turned to on.
C. Power switch to the fryer section in the off
position.
D. Frying oil at proper level in fry tank and below last
set point temperature used.
E. Cooking control is setup properly and ready to
use.
F. Manual drain valve closed (drain valve interlock
switch N.O. is closed).
G. High limit thermostat closed.
2. Press power on switch.
A. Power to terminal 5 (com) on left and right basket
relays.
B. 24VAC transformer 1T energized.
3. Cooking control powers on, initializes and performs a
diagnostic self check.
NOTE: If the control passes self check, then the outputs
are energized and operation sequence continues. If
control does not pass self test, the control will display
the appropriate message for the problem, disable the
keypad and the electronic alarm will sound continuously.
Refer to "TROUBLESHOOTING".
A. Ignition module is powered (24VAC), initializes
and generates spark at ignitor.
1) Pilot voltage (PV) N.O. contacts close, pilot valve
energized at positive (+) terminal and opens for gas
flow to pilot.
a. Pilot flame established. A micro amp "flame
sense" current is rectified to ignition module
through ignitor cable and sparking stops.
b. Main voltage (MV) N.O. contacts close and
provides ignition status input signal (24VAC) to
cooking control at pin E1-6.
NOTE: If pilot ignition is not established within the
first several seconds of ignition trial time, the
cooking control displays a message indicating
"pilot out" or "ignition failure" as the ignition
module continues to generate a spark at the
ignitor. If pilot is not established within 90 seconds
of the ignition module being energized, the ignition
module locks out power to the gas valve. A
message is displayed by the control indicating
"ignition lockout"; keypad is disabled and the
electronic alarm will sound continuously. The
system remains locked out until the power switch
is cycled to reset the system and re-start the
ignition trial cycle.
4. Cooking control evaluates the input from: Ignition
status at pin E1-6; Drain valve interlock at pin E1-5;
And temperature probe at pins E1-3 and E1-4 (high &
low).
A. If the inputs to the control are valid and the frying
oil temperature is below set point, the heat output
(24VAC) at pin E1-8 is then activated and power is
applied to heat control Triac.
1) Heat control Triac energized and supplies
voltage to gas valve TH terminal.
a. Main gas valve energized and opens for gas
flow to burners.
b. Burners light and begin heating frying oil in fry
tank.
NOTE: As long as the ignition control module
senses a pilot flame, the internal main voltage
(M V) contacts (N.O.) on the ignition module
remain closed, and main gas valve stays on.
5. Frying oil reaches set temperature.
A. Cooking control de-activates the heat output
(24VAC) at pin E1-8 and power is removed from
heat control Triac.
1) Main gas valve de-energized and closes.
a. Gas flow stops and burners go out.
– 31 –
F-25114 Rev.A (07-03)