Service manual

Section 6 Electrical System
Part No. 80-1206-3 6-3
Energized Parts Charts
QDUALC
*Low Pressure Control (close on pressure increase).
1. Initial Start-Up or Start-Up After Automatic Shut-Off
2. Contactor Coil energizes in Water Purge when suction pressure exceeds 22 psig.
3. The fan motor is wired through a fan cycle pressure control, therefore, it may cycle on and off.
Safety Timers
The control board has the following non-adjustable safety timers:
Freeze Sequence:
• The ice machine is locked in the Freeze Sequence 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.
Harvest Sequence:
• The maximum harvest time is 7 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. If the bin switch is closed, the ice
machine will go to the Freeze Sequence.
Ice Making
Sequence Of
Operation
Control Board Relays Condensing Unit
Length
Of
Time
1 2 3 4 5 6 LPC* Contactor
Water
Pump
Water Fill
Valve
Dump
Solenoid
Liquid
Line
Solenoid
Valve
Cool
Vapor
Valve 1
Cool
Vapor
Valve 2
Contactor
Coil
Compressor/
Condenser
Fan Motor
START-UP
1
1. Water Purge
On Off On Off On On Closed On 45 Sec.
2. Refrigeration
System
Start-Up
Off On Off On On On Closed On
2
5 Sec.
FREEZE
SEQUENCE
3. Pre-Chill
Off
On until
Water
Sensed
Off On Off Off Closed On
2
30 Sec.
4. Freeze On
Cycles Off
then On
1more
time
Off On Off Off Closed On
2
Until 10
sec.
water
contact
with ice
thickness
probe
HARVEST
SEQUENCE
5. Water Purge
On
30 sec.
Off,
15 sec. On
On On On On Closed On
2
Factory-
set at 45
Seconds
6. Harvest Off Off Off On On On Closed On
2
Bin
switch
activation
7. AUTOMATIC
SHUT-OFF
Off Off Off Off Off Off Open Off
Until bin
switch re-
closes