Troubleshooting - Profroid GFS ZF 09DZ Handbuch

TROUBLESHOOTING

10-
Examples of faults and solutions
FAULT PROBABLE CAUSE
Too much suction gas superheat
1. Suction
Temperature too
high
2. Suction Liquid in the suction line.
Temperature too Sensor bulb is loose or incorrectly positioned.
low
3. Suction Too much oil in evaporators.
Pressure too low
Filter in the liquid line clogged.
Suction filter blocked.
Too much superheat of suction gas.
Thermostatic expansion valve blocked when in
closed position.
Problem with solenoid valve in the liquid line.
Installation insufficiently charged.
4. Compressor cuts See point 3
in and out too
Low pressure safety switch set too high.
often on LP safety Evaporator iced over or frozen water present in
switch the distributor.
5. Suction Restart after defrost.
Pressure too high Compression problems
6. Condenser
Insufficient flow of air in to the condenser
Pressure too high Fan cut in not adjusted correctly
High pressure safety valve set too low
Installation flooded
Air or non-condensable gas in the HP circuit
Fan cut-in incorrectly set.
7. Condenser
pressure too low
8. Discharge Too much superheat on suction.
Temperature too
Internal by-pass.
high
9. Oil temperature Superheat on suction too great.
too high
Valve problems.
10. Oil Crankcase heater out of order.
temperature too Oil return saturated in liquid refrigerant
low
Problem with control system or other automatic
11. Capacity too
devices.
great
12. Insufficient Problem with control system or other automatic
devices.
Capacity
13. Oil foams Thermostatic expansion valve (fluid in suction
line).
heavily after
Bulb loose or incorrectly positioned
stoppage
Crankcase heater out of order
ACTION REQUIRED
Examine and adjust the thermostatic expansion
valves in the evaporators.
Adjust thermostatic expansion valves.
Check if the bulb is in contact with the suction line
and replace if necessary
Drain oil from evaporators.
Examine and clean filters in liquid line.
Check suction filter.
Adjust thermostatic expansion valves.
De-ice thermostatic expansion valve using warm
rags. If no improvement, change the thermostatic
expansion valve.
Check wiring and coil – replace if necessary
Charge the installation with refrigerant.
Adjust pressure safety switch.
Clean or defrost evaporator.
Wait for confirmation
Change compressor
Clean the condenser. Check motor fans
Adjust
Set pressure valve at maximum 1 bar below
Maximum Safe Pressure, but take into account the
compressor limit.
Drain liquid into reservoir
Let air out at highest point.
Adjust pressure switch
Adjust thermostatic expansion valves.
Check pressures.
Check and adjust thermostatic expansion valves
Check pressures. If necessary, adjust valves and
gaskets.
Replace heater
Adjust thermostatic expansion valve
Replace, repair or re-set
Replace, repair or re-set.
Check thermostatic expansion valve.
Check bulb position
Replace heater
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