Refrigeration System; Refrigeration System Adjustments; Expansion Valve; Adjustment And Troubleshooting - Cornelius 500 Series Service Manual

Continuous Flow Icemaker Service Manual

REFRIGERATION SYSTEM

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EFRIGERATION
A complete understanding of the icemaker and hermetic refrigeration system is necessary before any adjustments
are made. The refrigeration technician must use high and low side pressure readings, water and air temperatures,
plus general conditions of cleanliness to assess the refrigeration system status when making any adjustments.
All icemaker products are tested and adjusted at the factory prior to shipment where the ambient temperature
ranges from 65° to 90°F, depending on the season of the year.
Whenever a new icemaker product is initially installed and started–up, it is imperative that the start–up operation
make the following checks and/or readjustments for local conditions.
E V
XPANSION ALVE
You will find a thermostatic expansion valve on icemakers, which is used to control the amount of refrigerant flowing
through the evaporator. Improperly installed or defective expansion valves may cause low production, soft ice,
squeaking from evaporator and excessive load inside evaporator.
By using general refrigeration system troubleshooting along with the pressure charts you can easily determine
whether or not the expansion valve is working properly.
A
DJUSTMENT AND
When troubleshooting the expansion valve you must first be sure you have adequate water flowing into evaporator,
a clean condenser, unit is properly ventilated, and system is properly charged and free from any restrictions. Also
be sure compressor is operating properly.
Second, take reservoir water temperature and air temperature from condenser inlet and determine at what
pressure unit should be running. Machines are equipped with thermostatic valves, there is NO adjustment. If
correct pressure cannot be obtained, first be sure system has time to stabilize 10–15 minutes. Second, be sure
sensing bulb is located at 12:00 position on outlet side of evaporator about 3–4 inches away from evaporator and
be sure to insulate well and clamp tightly to tubing. If system pressures are still not adequate, take a second water
and air temperature reading and go over other parts of system for possible problems. If proper charge is
questionable evacuate and recharge to nameplate and leak check. If valve still malfunctions replace valve.
When replacing valve be sure to bleed refrigerant gas from low side port so as not to lose refrigerant oil. Use
general refrigerant system practices when replacing and recharging unit. After new valve is in place, go through
previous monitored adjustments and troubleshooting to be sure valve is functioning properly.
NOTE: Units with thermostatic expansion valve—valve is located on bottom refrigerant line. Sens-
ing bulb is located on top refrigerant line. On water cooled units adjust condenser modulating
valve before troubleshooting expansion valve.
!
CAUTION:
Very High discharge pressure is present in system. Quick disconnects on you gauges will minimize danger and loss of
refrigerant. Comply with federal regulations for reclaiming refrigerant.
Publication Number: 630460174SER
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YSTEM DJUSTMENTS
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ROUBLESHOOTING
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