Manitowoc J-1300, Service Manual

Page: 52 / 165

Section 6 Electrical System
6-1
Section 6 Electrical System
Energized Parts Charts
SELF-CONTAINED AIR- AND WATER-COOLED MODELS
Ice Making Control Board Relays Contactor
Sequence 1 2 3 4 4A 4B Length
Of
Operation
Water
Pump
Hot Gas
Valve
Water
Dump
Valve
Contactor
Coil
Compressor
Condenser
Fan Motor
Of
Time
Start-Up
1
1. Water Purge
On On On Off Off Off 45 Seconds
2. Refrigeration
System Start-Up
Off On Off On On
May Cycle
On/Off
5 Seconds
Freeze
Sequence
3. Pre-Chill
Off Off Off On On
May Cycle
On/Off
30 Seconds
4. Freeze
On Off Off On On
May Cycle
On/Off
Until 7 sec. water
contact with ice
thickness probe
Harvest
Sequence
5. Water Purge
On On On On On
May Cycle
On/Off
Factory-set at
45 Seconds
6. Harvest
Off On Off On On
May Cycle
On/Off
Bin switch
activation
7.
Automatic
Shut-Off
Off Off Off Off Off Off
Until bin switch
re-closes
1
Initial Start-Up or Start-Up After Automatic Shut-Off
Condenser Fan Motor
The fan motor is wired through a fan cycle pressure
control, therefore, it may cycle on and off.
Harvest Water Purge
New style circuit boards have an adjustable water
purge in the havest cycle. This permits a 0 (off), 15,
30 or 45 second purge cycle.
Auto Shut-Off
The ice machine remains off for 3 minutes before it
can automatically restart. The ice machine restarts
(steps 1-2) immediately after the delay period, if the
bin switch re-closes prior to 3 minutes.
Safety Timers
The control board has the following non-adjustable
safety timers:
FREEZE SEQUENCE
•
The ice machine is locked into the freeze cycle
for the first 6 minutes, not allowing the ice
thickness probe to initiate a harvest sequence.
•
The maximum freeze time is 60 minutes, at which
time the control board automatically initiates a
harvest sequence (steps 5-6).
HARVEST SEQUENCE
•
The maximum harvest time is 3-1/2 minutes, at
which time the control board automatically
terminates the harvest sequence. If the bin switch
is open, the ice machine will go to automatic
shut-off (step7). If the bin switch is closed, the ice
machine will go to the freeze sequence
(steps 3-4).