Service manual

UC 701 Series Continuous Flow Icemaker Installation and Service Manual
Publication Number: 630460150 - 12 - © 2000-2014, Cornelius Inc.
REFRIGERATION SYSTEM
Refrigerant
Type R404A
±10 lbs. Discharge Pressure
Water Temperature (°F)
Air Temperature (°F)
40 65 90
50 174 177 180
60 202 205 208
70 230 233 236
80 265 269 272
90 300 304 307
100 328 334 340
NOTE: Thermostatic Expansion Valve is non-adjustable on all models.
REFRIGERATION SYSTEM ADJUSTMENTS
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
r
anges 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
ma
ke the following checks and/or readjustments for local conditions.
EXPANSION VALVE
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.
ADJUSTMENT AND TROUBLESHOOTING
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
p
ressure 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—The
valve is located on bottom refrigerant line.
Sensing bulb is located on top refrigerant line. On water cooled units adjust condenser modulating
valve before troubleshooting expansion valve.