Flake Ice Machines | Refrigeration System |
Expansion Valve Diagnosis
Symptom
Single Evaporator Machine
1.Evaporator flooded but suction pressure too high. Compressor has been checked and appears to be good. Suction line at compressor may be colder than normal.
2.Evaporator starved, no frost on line exiting evaporator. Suction pressure low.
Dual Evaporator Machine
1.Evaporator flooded but suction pressure too high. Compressor has been checked and appears to be good. Suction line at compressor may be colder than normal.
2.One evaporator starved and one evaporator properly flooded, suction pressure lower than normal.
Problem
a.TXV sensing bulb uninsulated or not making good contact with suction line.
b.TXV sensing bulb in wrong location.
c.System overcharged.
d.TXV stuck open.
a.Machine low on charge.
b.TXV restricted or stuck closed.
a.Machine low on charge.
b.TXV restricted or stuck closed.
c.System overcharged.
d.An expansion valve stuck open.
a.TXV restricted or sticking closed.
Remedy
a.Clean suction line and clamp bulb securely. Insulate bulb.
b.Relocate sensing bulb to top of suction line.
c.Recover refrigerant and weigh in correct charge.
d.Replace TXV.
a.Recover refrigerant and weigh in correct charge.
b.Replace TXV and filter- drier.
a.Recover refrigerant and weigh in proper charge.
b.Replace TXV and filter- drier.
c.Recover refrigerant and weigh in correct charge.
d.Replace TXV.
a. Replace defective TXV
Production Check
Check ice production by allowing the machine to produce ice into a container for 15 minutes. If the machine has 2 evaporators, be sure to collect the ice from each evaporator separately so that production from each evaporator can be checked. Weigh the ice in each container and multiply the weight by 96. This will give you the approximate production in a 24 hour period.
Weight of ice produced in 15 minutes X 96 =production in 24 hours.
Note: Verify that the condenser is clean and the inlet water temperature and level is correct prior to performing a production check.
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