Probe Tip And Swivel; Cam Switch Operation-Single Evaporator Machines; Cam Switch Operation-Dual Evaporator Machines - Cornelius CCM0330 Service And Maintenance Manual

Probe Tip and Swivel

The probe tip is attached to the clutch and makes contact with the back of the ice slab during
harvest. The swivel allows the probe tip to pivot as the clutch turns so that the probe is pushed
straight through the evaporator probe guide.
The tip of the probe should be flush with the back of the evaporator or recessed up the 1/16 of an
inch (.16cm). The probe tip must not extend into the freezing area of the evaporator during freeze.
If the probe tip binds during operation it may cause the clutch to slip unnecessarily. This may
occur if the harvest motor mounting bracket is not aligned properly or if the probe tip has excessive
mineral deposits on it. Remove and clean the probe if necessary.
To check the probe tip for binding, remove the shoulder bolt holding the swivel to the clutch and
simulate the movement of the swivel and probe by moving the swivel in a circular motion around
the outer portion of the clutch. The swivel should also move freely. If any resistance is felt the
bracket should be adjusted by loosening the bracket mounting screws and repositioning the
bracket until the probe moves freely.

Cam Switch Operation-Single Evaporator Machines

The actuator arm of the cam switch rides on the edge of the clutch assembly and is actuated by
the high and low portion of the cam. When the machine is in the freeze cycle the actuator arm of
the cam switch is in the low part of the cam. During freeze, power is supplied to the water pump
and relay 2, through the normally closed contacts of the cam switch. When the machine enters
harvest, power is supplied to the water pump and purge valve through the normally closed
contacts of the cam switch and through the normally open contacts of relay 1 (closed during
harvest). The water pump, purge valve and relay 1 remain energized until the cam switch is lifted
on to the high part of the cam. Relay 2 will also de-energize at this time allowing the machine to
shut off if the bin switch opens. Undercounter machines will have the water pump run continually
until the machine shuts down.
Cam Switch Operation-Dual Evaporator Machines (Prior to January 2008)
Once the freeze timer has counted out, power is sent to: (A) harvest motor 1 and relay coil 1
through the normally closed contacts of cam switch 1, (B) to harvest motor 2 and relay coil 2
through the normally closed contacts of cam switch 2.
This 4-second delay will allow the harvest motors to rotate and allow the cam switches to switch to
the normally open position before the low-pressure control opens during hot gas. The cam
switches are now in the normally open position and will continue to energize the harvest motors
and relays until the cam rotates and the switch returns to the normally closed position.
The bin switches are bypassed to allow the cam switch to return to the normally closed position,
prior to the machine shutting down if the curtain is open. Each harvest assist motor will only make
one revolution prior to shutting down on full bin or advancing to the next freeze cycle.
Both hot gas valves and the water purge valve remain energized until both harvest assist motors
complete one revolution. The water pump is energized throughout the harvest cycle. The unit will
shut down if the curtains are open during the freeze cycle.
Page F7
Electrical System