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Flake Ice Machines Refrigeration System
Page F8
Expansion Valve Diagnosis
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.
Symptom
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.
Problem
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
Remedy
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.