Profroid GSB Notice D'instructions page 38

10- TROUBLESHOOTING
Examples of faults and solutions
FAULT PROBABLE CAUSE
1. Suction Too much suction gas superheat
Temperature too (above 20K)
high
2. Suction Liquid in the suction line.
Sensor bulb is loose or incorrectly positioned.
Temperature too
low
Too much oil in evaporators.
3. Suction
Filter in the fluid line clogged.
Pressure too low
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
Condenser pipe blocked by deposits of mud or scale.
Cooling liquid too hot.
Water filter blocked.
High pressure safety valve set too low
Installation flooded
Air or non-condensable gas in the HP circuit
Condenser
Too much water in condenser.
7.
pressure too low Fan cut-in incorrectly set.
Too much superheat on suction.
8. Discharge
Temperature too Internal by-pass.
high
9. Oil Pressure too
Crankcase heater out of order. Fluid diluted.
low
Level too low
Suction filter blocked
Oil pump out of order
Liquid Refrigerant fluid flows back
Bulb is loose or incorrectly positioned
Superheat on suction too great.
Oil
10.
temperature too Valve problems.
high
Oil Crankcase heater out of order.
11.
temperature too Oil return saturated in liquid refrigerant
low
12. Drop in pressure
Oil filter blocked.
in oil filter too
great.
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
Check valves and joints
Adjust water supply or clean condenser. Check motor
fans.
Clean condenser pipe.
Find colder cooling water
Clean water filter
Set pressure valve at maximum 1 bar below
Maximum Safe Pressure, but take into account the
compressor limit.
Drain liquid into receiver
Let air out at highest point.
Adjust water supply
Adjust pressure switch
Adjust thermostatic expansion valves.
Check valves and joints.
Change crankcase heater
Check before each refill
Remove and clean
Change oil pump
Adjust installation expansion valves
Tighten bulb
Check and adjust thermostatic expansion valves
Check pressures. If necessary, adjust valves and
gaskets.
Replace heater
Adjust thermostatic expansion valve
Replace filter. Do not operate without filter
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