Service manual

PART NUMBER 145702, REV. C (01/07)
CALL 888-994-7636 FOR TECHNICAL SUPPORT
20
TROUBLESHOOTING
Look for temperature rise on the
dial temperature guage
Set timer to one minute
Push MANUAL
Heats to 200 + degrees in
22 +/- 5 minutes
No defect found but customer
complaint is that unit is slow
to heat
Timer colon flashes times out,
HOLD light illuminates, and unit
beeps until CANCEL button is
pushed
MANUAL light illuminates and
timer displays dashes
Heater element
Incorrect wiring
Customer may be opening
door frequently to add or
remove food
Line voltage may be low
Not at ready temperature or
door is open
Control board
Incorrect wiring
Control board
Measure amperage for each
leg and compare to the chart
on next page. If amperage is
incorrect, disconnect power,
measure heater resistance (cold),
and compare to the chart on
next page. If resistance
is not within 20% of specified,
replace heater element
Check per wiring diagram
Talk with customer
Measure line voltage
Close door, wait for ready
Substitute to test
Check per wiring diagram
Substitute to test
SETUP EXPECTED RESULTS PROBABLE DEFECT TEST or COMMENTS
CONGRATULATIONS!
The unit is operating correctly.
PART NUMBER 145702, REV. B (7/06)
Call 1-800/676-9040 for Technical Support
4 4
4.2 VRC Checkout
1. Apply power to the VRC. On the back of the front-panel control
board, flip the left DIPswitch up to start the diagnostics.
2. The red 7-segment display on the front panel should have some
of its segments lit. If they are not then check the fuse and circuit
breaker on the control transformer. Then check that all har-
nesses are in place and that the connectors are properly seated.
Check for 24 VAC at the secondary of the control transformer.
3. Turn the knob so that the red display shows A1 (Analog 1 – RTD
temperature). The green display should show the approximate
temperature of the RTD probe in the cavity. If it shows a very
small number or zero then the harness connecting the RTD to
the control board is probably shorted to ground. If the number
is very large – around 250 or more – it means the RTD or its
harness is open or disconnected.
4. Turn the knob to A4 (Analog 4 – Line voltage). The green display
should show the approximate line voltage.
5. Turn the knob to b (button). Push each button. The light near the
button should light. Also, check that pushing the top two buttons
makes the bottom two lights go out.
6. Turn the knob to P (Product code). The green display should
show 001 for a standard VRC or 003 for an auto-fill VRC. If any
other number is displayed the ribbon cable connecting the
front-panel control board to the relay board is incorrect.
7. Turn the knob to S (Sensors). As each sensor is activated the
associated green bar will light. If it doesn’t then that sensor or
harness connection is faulty. Refer to this diagram:
8. Lift the hi float and hold it up. The Hi Float bar should light after
a few seconds. Release the float.
9. Lift the lo float and hold it up. The Lo Float bar should light after
a few seconds. Release the float.
10. Close and open the door. The Door Open bar should go out
when the door is closed. Use a magnet to check the door switch
on the other side. The bar should go out when the magnet is
near the door sensor.
11. Push the ON end of the rocker switch. The Power bar should
light. Push the OFF end of the switch. The bar should go out.
12. On the left side of the VRC, under the heater plate at the front,
disconnect one of the terminals on the thermostat closest to
the front panel. The Overtemp bar (the one in the middle of
the display) should light. If the Heater Overtemp bar (the top
one) lights then the wiring to the two thermostats is probably
crossed. Reconnect the terminal. The Overtemp (middle) bar
should go out.
13. Disconnect one of the terminals on the thermostat farthest from
the front panel. The Heater Overtemp (top) bar should light.
Reconnect the terminal. The Heater Overtemp (top) bar should
go out.
14. Turn the knob to O1 (Output 1 - Shutdown). Push the ON (upper)
end of the rocker switch. The large contactor closest to the back
panel should pull in. Push the MANUAL button. The contactor
should drop out.
15. If the VRC is equipped with auto-fill turn the knob to O2 (Output
2 – Fill valve). Push the MANUAL button a few times. The fill
valve should open whenever the button is pushed.
16. Turn the knob to O6 (Output 6 - Heater). Push the ON end of
the rocker switch. Lift the lower float all the way up and hold it
up. Push the MANUAL button a few times. The large contactor
closest to the front panel should pull in whenever the button is
pushed. Check for proper line current on all three phases when
the button is pushed. Note: For the heater to turn on the power
must be on, the lower float must be up, and the overtemp ther-
mostat must be operating properly.
17. Turn the knob to O7 (Output 7 – Fan). Push the MANUAL button.
The fan should run.
18. Turn the knob to O8 (Output 8 – Beeper). Push the MANUAL but-
ton. The beeper should beep.
19. Turn the knob to 88. All lights and all display segments should
light.
20. On the back of the front-panel control board, flip the left DIP-
switch down to start normal VRC operation. The red heartbeat
LED on the back of the control board should blink about once a
second.
21. Perform the normal VRC checkout (add water, check steam
production, etc.).
Diagnostic Switch Summary
A1 Analog 1 – RTD temperature
A2 Analog 2 – RTD millivolts
A3 Analog 3 – Control board temperature
A4 Analog 4 – Line voltage
b Button test
P Product code
S Sensor outputs
Error Codes
1 Lo float changed state while hi float on
2 Hi float changed state while lo float off
3 Cold fill to hi float time exceeded Fatal
4 Hot refill to hi float time exceeded Fatal
5 Controller temperature exceeded Fatal
6 Cavity temperature exceeded Fatal
7 Drain box temperature exceeded Fatal
8 Drain time exceeded
9 RTD is open Fatal
10 RTD is shorted Fatal
11 Control board is too hot Fatal
99 No product code in connecting cable Fatal
Hi Float
Lo Float
Door Open
Power
Heater Overtemp
Overtemp
Sensor LED Bars
O1 Output 1 – Shutdown
O2 Output 2 – Fill valve
O3 Output 3 – Spray valve
O4 Output 4 – Drain valve
O5 Output 5 – Eductor valve
O6 Output 6 – Heater (ON and
low float up)
O7 Output 7 – Fan
O8 Output 8 – Beeper
88 All lights on