Vulcan-Hart ML-126610, Service Manual

Page: 36 / 75

MENU
ALTERNATING ON DISPLAY
PARAMETER DATA
Range High 1 rH1 500
Hysteresis HYS1 3
Calibration Offset CAL1 0
Exit Setup Mode
and return to
Operation Mode. set point temperature is
displayed or if call for heat,
dashes (----) displayed.
Probe Test
1. Set the control to 350°F.
2. Access the back of the control panel to
disconnect the probe lead wires.
3. Install a jumper wire across the probe terminals.
This will simulate room temperature.
A. If the heat light comes on and the actual
temperature is room temperature, replace
the probe.
B. If the heat light does not come on or the
actual temperature is not room temperature,
replace the control.
Solid State Relay Test
1. Remove the Right Side Panel.
2. Set the temperature to 350°F or high enough to
keep the heat ON for several minutes.
3. Check for +5 VDC on input side of SSR
(terminals 3 & 4).
A. If +5 VDC is present, continue to step 4.
B. If no voltage is present, computer control is
not functioning properly.
4. Check for 120 VAC at load side of SSR (terminals
1 & 2).
A. If no voltage is present, solid state relay is
not functioning properly.
1) Replace the SSR and check for proper
operation.
B. If 120 VAC is present, component is
functioning properly.
5. Re-assemble oven and check for proper
operation.
COMPUTER CONTROL
CALIBRATION (VC4GC/VC6GC)
1. Place a thermocouple in the geometric center of
the oven cavity.
2. Press the set key then temperature key to enter
the temperature set mode.
A. The display will alternate between the term
"StPt" (set point) and the current oven
temperature setting.
B. Press the up or down arrow keys to make
the proper selection.
C. Press the set key again to save the change
and exit the temperature set mode.
3. Allow the oven temperature to stabilize (normally
3 cycles).
4. Set the ON-OFF-COOL DOWN switch to ON.
A. If the set point temperature is 350°F,
proceed to step 4.
B. If the set point temperature is other than
350°F, proceed to step 3 to change the
temperature.
5. Compare the controls set point temperature to
the thermocouple meter reading when the heat
light goes out.
A. A temperature variance more than 5°F
indicates an adjustment is needed.
1) To make the adjustment, proceed to
step 6.
2) If temperature variance is less than
5°F, computer control is functioning
properly.
6. Enter the .
A. Advance through the menu until CAL1
(Calibration Offset) appears.
1) If the thermocouple reading is higher
than set point temperature, press the
down arrow key and enter a negative
offset value that is equal to the number
of degrees above the 5°F tolerance.
2) If the thermocouple reading is lower
than set point temperature, press the
up arrow key and enter a positive offset
value that is equal to the number of
degrees below the 5°F tolerance.
3) Exit the setup mode.
7. Allow the oven to cycle at least two times
between adjustments.
A. If the temperature variance still differs
more than 5°F from the set point, verify the
correct calibration offset value was entered
and retained.
VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS
F24682 Rev. D (1016) Page 36 of 75