Service Procedures And Adjustments; Temperature Probe Test; Cooking Control Calibration - Vulcan-Hart GRC35 Service Manual

GR SERIES GAS FRYERS - SERVICE PROCEDURES AND ADJUSTMENTS

SERVICE PROCEDURES AND ADJUSTMENTS

WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TEST OR MEASUREMENTS
WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL TIMES. IF TEST POINTS
ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST EQUIPMENT AND REAPPLY POWER TO
TEST.

TEMPERATURE PROBE TEST

The temperature probe is used for both the solid state
control and the computer control. The probe is an RTD
(resistance temperature detector) of the thermistor type.
As temperature increases the resistance value
decreases.
Probe Fault
If a temperature probe fault or high temperature
condition occurs, a fault message will be displayed and
the electronic alarm will sound continuously. The heat
demand and basket lift outputs are deactivated. If a
cooking cycle is in process (timer active), it will be
cancelled and the key pad disabled.
This will continue until the fault clears, power is cycled
or problem resolved.
Control Type Display Message
SOLID STATE An open will display "Prob" and
a short or high temperature
condition will display "HI".
COMPUTER An open will display "PROBE
OPEN" and a short or high
temperature condition will
display "PROBE SHORT".
To Check:
1. Disconnect the temperature probe & the drain valve
interlock (DVI) connector.
NOTE: The connector has 6 pin positions and is labeled
"G" on the wiring diagram.
2. Test the probe using a VOM to measure resistance.
Place the meter probe leads in pins 1 & 3.
A. If the measured resistance values are within the
allowable range, the probe is functioning properly.
Reverse procedure to re-install.
B. If the measured resistance values are outside the
allowable range, install a replacement probe and
check for proper operation.
Temperature (°F)
77
350
415
1
460
2
NOTE: 1. High temperature alarm level for the cooking
controls.
2. Shorted probe equivalent temperature.

COOKING CONTROL CALIBRATION

1. Check the level of frying oil in tank. The level must be
between the MIN & MAX fill lines before proceeding.
2. Allow the oil to cool below 300°F.
3. Place a thermocouple in the geometric center of the
fry tank one inch below the oil surface.
4. Set the cooking control to 350°F and turn the fryer
on.
5. Allow the frying oil temperature to stabilize (normally
3 cycles).
NOTE: Agitate the frying oil, to eliminate any cold
zones.
6. Record the temperature reading from the meter, at
which the gas burners turn off and turn on for at least
two complete heating cycles.
7. Calculate the average temperature by adding the
temperature reading when the gas burners turn off to
the temperature reading when the gas burners turn
on and divide this answer by 2.
[ Temp. (burners off) + Temp. (burners on) ] ÷ 2 =
Example: 360° + 340° ÷ 2 = 350°F.
The average temperature should be 350°F (± 5°F).
– 19 –
Resistance (
90,000 - 110,000
604 - 836
302 - 369
191 - 233
Average Temp.
F-25114 Rev.A (07-03)
É É É É É
)