Section 7 | Refrigeration System |
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EQUALIZATION VALVE (QF2300)
General
The equalization valve is an electrically operated valve that closes when energized, and opens when de- energized.
Normal Operation
The valve is energized (closed) during the freeze cycle and
Analysis
The valve can fail in two positions:
•Valve will not open in the off cycle.
•Valve remains open during the freeze cycle.
VALVE WILL NOT OPEN IN THE OFF CYCLE Discharge and suction pressure will not equalize.
VALVE REMAINS OPEN IN THE FREEZE CYCLE:
Symptoms of a equalization valve remaining partially open during the freeze cycle can be similar to symptoms of an expansion valve or compressor problem. Symptoms are dependent on the amount of leakage in the freeze cycle.
A small amount of leakage will result in poor quality ice. As the size of the leak increases ice quantity will decrease until ice production stops completely.
A small amount of leakage will cause an audible indication as the vapor passes through the valve. As the size of the leak increases the audible indication becomes more apparent.
Refer to the Parts Manual for proper valve application. When replacement is necessary, use only “original” Manitowoc replacement parts.
WATER REGULATING VALVE (WATER-COOLED MODELS ONLY)
General
The water regulating valve maintains the freeze cycle discharge pressure.
Check Procedure
1.Determine if the head pressure is high or low (refer to “Operational Pressure Charts”).
2.Verify the condenser water meets specifications (refer to Section 2 for specifications).
3.Adjust valve to increase or decrease discharge pressure.
4.If the valve will not maintain the correct discharge pressure clean or replace as needed.
Part No. | Revised 8/2003 | |
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