Qdual; Initial Start-Up Or Start-Up After Automatic Shut-Off - Manitowoc QR0670C Technician Manual

QDUAL

Initial Start-Up or Start-Up After Automatic Shut-Off

1. Water Purge
Before the refrigeration system starts, the water pump
and water dump solenoid are energized for 45 seconds,
to purge the ice machine of old water. This feature
ensures that the ice-making cycle starts with fresh
water. The cool vapor solenoid valves are also
energized during the water purge, although they stay
on for an additional 5 seconds (50 seconds total on
time) then shut off.
2. Refrigeration System Start-Up
Ice Machine Section: The liquid line solenoid valve
energizes after the 45-second water purge, and
remains on throughout the entire Freeze and Harvest
sequences. The cool vapor solenoid valves remain on
for 5 seconds during initial compressor start-up and
then shut off.
The water fill valve is energized at the same time as
the liquid line solenoid valve.
®
CVD Condensing Unit: When the refrigerant pressure
is high enough to close the low pressure control (after
the cool vapor valves energize in step 1), the contactor
coil is energized and the compressor starts. The
compressor and fan cycling control are supplied with
power throughout the entire Freeze and Harvest
sequences. When the refrigerant pressure is high
enough to close the fan cycling pressure control, the
condenser fan motor starts.
–84–