Manitowoc S1000M, Service Manual

Page: 62 / 100

Electrical System Section 6
6-24
Part Number 80-1559-3
Water Level Control Circuitry
WATER LEVEL PROBE LIGHT
The water level probe circuit can be monitored by
watching the water level light. The water level light is on
when water contacts the probe, and off when no water is
in contact with the probe. The water level light functions
any time power is applied to the ice machine, regardless
of toggle switch position.
During the freeze cycle, the water level probe is set to
maintain the proper water level above the water pump
housing. The water level is not adjustable. If the water
level is incorrect, check the water level probe position.
Reposition or replace the probe as necessary.
WATER INLET VALVE SAFETY SHUT-OFF
In the event of a water level probe failure, this feature
limits the water inlet valve to a 12-minute on time.
Regardless of the water level probe input, the control
board automatically shuts off the water inlet valve if it
remains on for 12 continuous minutes.
FREEZE CYCLE CIRCUITRY
Manitowoc’s electronic sensing circuit does not rely on
float switches or timers to maintain consistent water
level control. During the freeze cycle, the water inlet
valve energizes (turns on) and de-energizes (turns off) in
conjunction with the water level probe located in the
water trough.
During the first 45 seconds of the Freeze Cycle:
• The water inlet valve is on when there is no water in
contact with the water level probe.
• The water inlet valve turns off after water contacts
the water level probe for 3 continuous seconds.
• The water inlet valve will cycle on and off as many
times as needed to fill the water trough.
After 45 seconds into the Freeze Cycle:
The water inlet valve will cycle on, and then off one more
time to refill the water trough. The water inlet valve is
now off for the duration of the freeze sequence.
HARVEST CYCLE CIRCUITRY
The water level probe does not control the water inlet
valve during the harvest cycle. During the harvest cycle
water purge, the water inlet valve energizes and de-
energizes strictly by time. The harvest water purge
jumper may be set at 45 seconds (top and center
terminals) or 0 seconds (center and bottom terminals).
Set the harvest water purge to 0 seconds when reverse
osmosis or deionized water is used. Use the factory
setting of 45 seconds for all other types of water.
45 SECOND
JUMPER
POSITION
0 SECOND
JUMPER
POSITION
HARVEST WATER PURGE ADJUSTMENT
SV3139
SV3140