Manitowoc Ice CM MODEL STH003 - Manual (Page 53)

53
HOT GAS VALVE ANALYSIS
The valve can fail in two positions:
• Valve will not open in the harvest cycle.
• Valve remains open during the freeze cycle.
Valve will not open in the harvest cycle
Although the circuit board has initiated a harvest cycle,
the evaporator temperature remains unchanged from
the freeze cycle.
Valve remains open in the freeze cycle:
Symptoms are dependent on the amount of leakage in
the freeze cycle. A small amount of leakage will cause
increased freeze cycle times. A large amount of
leakage will result in no ice produced.
Use the following procedure and table to help
determine if a hot gas valve is remaining partially open
during the freeze cycle.
1. Wait five minutes into the freeze cycle.
1. Feel the inlet of the hot gas valve(s).
IMPORTANT
Feeling the hot gas valve outlet or across the hot
gas valve itself will not work for this comparison.
The hot gas valve outlet is on the suction side (cool
refrigerant). It may be cool enough to touch even if
the valve is leaking.
WARNING
The inlet of the hot gas valve and the compressor
discharge line could be hot enough to burn your
hand. Just touch them momentarily
2. Feel the compressor discharge line.
3. Compare the temperature of the inlet of the hot
gas valves to the temperature of the compressor
discharge line.