Cornelius 700 - Series, 2000 - Series Refrigeration System Adjustments, Expansion Valve

Continuous Flow Icemaker Service Manual

REFRIGERATION SYSTEM

Air Temperature

				Thermostatic Expansion Valve NO Adjustment.
						+/- 10 lbs. Discharge Pressure
						Water Temperature
		WCC 500					WCC 700				WCC 1000				WCC 2200
50°	40°		65°		90°	50°		65°	90°	50°		65°	90°	50°		65°	90°
	162		166		168	60°		177	180	60°		171	172	60°		201	203
60°
	188		‘92		194	70°		205	208	70°		199	200	70°		219	220
70°
	214		218		220	80°		233	236	80°		227	228	80°		253	254
80°
	245		249		251	90°		269	272	90°		263	264	90°		298	300
90°
	275		279		281	100°		304	307	100°		298	299	100°		330	332
100°
	309		313		315	328		334	340	324		328	332	362		364	366

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 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.

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 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. Sensing 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 - 12 - © 2004-2005, IMI Cornelius Inc.