Service manual

28
Installation and Service Manual
COMPONENT DIAGNOSTICS
Product Operation:
If the thermistor is "open" the cuber will start in the
harvest, or hot gas cycle, on a 3 relay board:
1. Adjusting the potentiometers ("pot") will not put
the cuber into a freeze mode.
2. Proximity switch will trip control board red light
off and on with water curtain movement, but,
product will remain in harvest mode when cur-
tain closes.
If the thermistor is "shorted" the cuber will remain in
the freeze cycle on a 3 relay board.
If thermistor passes flowchart test the thermistor is
OK - do not replace; check thermistor mounting and Er-
ratic Operation Troubleshooting Guide for bridge thick-
ness.
NOTE: BEFORE REPLACING THERMISTOR PLEASE
TEST USING CHECK PROCEDURE OR
FLOWCHART.
New generation circuit board (4 relays, remote
mounted transformer) - the power on light (LED) will flash
if there is a warning mode in the thermistor circuit.
NOTE: EV thermistor - Controls bridge thickness,
provides hi-temp safety cut-out on single
evaporator units and the left evaporator on
dual evaporator models.
High 2 thermistor - Dual evaporator models
only - right evaporator thermistor provides
high temperature safety shut-down.
ICE THICKNESS CONTROL REPLACEMENT
1. Shut off water and electric supply to the ice
maker.
2. Remove the float valve and water pan from the
machine. Remove the side panel from the con-
trol box side of the machine.
3. Use a 1/16" punch or allen wrench to push the
control out of the extrusion. Clean the old sili-
cone out of the hole.
4. Remove the old control from the machine.
Thread the new control through the machine from
the compressor compartment. Push the control
tip through the enclosure to the evaporator.
5. When routing the new control wires to the circuit
board be sure the wires do not touch any hot
gas lines. Attach the lead wires to the circuit
board in the appropriate positions. There is no
polarity in the wires of the ice thickness control.
6. If your old control has a plastic jacket, you must
redrill the control hole. Use a 5mm (11/64") drill
bit for this purpose. Use the drill bit by hand to
enlarge the hole to fit the metal jacketed control.
7. Using GE RTV-108 clear silicone only fill the hole
with silicone. This silicone is available from your
local Servend Distributor.
8. Immediately after filling the hole with silicone,
place your thumb over the front of the hole for
ice sensing control. Push the new control into
the hole from behind the evaporator. This will
allow the silicone to encompass outside the
contrl jacket. Continue to push the control into
the hole until you can feel the conrol hitting your
thumb. Never make a sharp bend with the con-
trol or allow the wire to loop behind the evapora-
tor. this can produce internal damage to the con-
trol.
9. The ice thickness control should be flush or pro-
trude through the hole 1/64" (.4mm). You may
feel a slight bump.
10. With your thumb still over the opening, wipe your
thumb sideways over and off the control. This
will allow a very slight silicone seal to remain on
the control tip.
11. Reinstall the side panel, water pan, float valve
and restore all utilities to the machine.
12. Wait for 15 minutes before allowing water to run
over the evaporator. This will allow the silicone
to dry tack free.
13. Check the water level in the water pan. turn the
machine to the ICE position.
14. Allow the machine to make one batch of ice. You
may check this sheet for proper bridge thickness.
If adjustment is necessary, please follow the pro-
cedure for your particular machine.