Unit installation

Use and Maintenance Manual Air-cooled water chillers and Heat Pumps R-PAE/R-PAH/EAH Rev. 1 del 03/09
TROUBLE POSSIBLE CAUSE CORRECTIVE ACTION
5. The high pressure switch
is activated
A) The high pressure switch is not set
properly or is defective
B) Discharge pressure too high
Replace the high pressure switch or reset it
See trouble 7
C) The condensing water flow capacity is
not sufficient
See trouble 4
A) The low pressure switch is not set properly Replace the low pressure switch or reset it
6. The low pressure switch
is activated
B) The cooled water flow capacity is not
sufficient
See trouble 4
C) Suction pressure too low See trouble 10
A) Suction pressure too high See trouble 9
B) The finned heat exchanger is dirty
Remove the obstructing material (leaves, paper,
seeds, etc.)
C) Circuit charged with too much refrigerant
High refrigerant undercooling: discharge some
refrigerant from the circuit
7. High compressor discharge
pressure
D) Non-condensable air or gas in the circuit
The flow sight glass shows gas bubbles. The compressor
discharge temperature is high; the cooling circuit must
be discharged and recharged after the vacuum execution.
E) Too hot water at the condenser
Check capacity of the condensation water cooling
system
F) Condensing water flow capacity
insufficient
See trouble 4
G) Encrusted condenser Wash the exchanger with suitable products
A) The control system of the condensation Check setting and operation of the thermostatic valve
8. Low compressor discharge pressure is not working properly
pressure
B) Suction pressure too low See trouble 10
A) Thermal load higher than estimated Check the room thermal load value
9. High compressor suction
B) Discharge pressure too high See trouble 7
pressure
C) Liquid refrigerant return to the compressor
suction side
Make sure the thermostatic valve overheating is
correct; check the valve bulb is properly placed, fixed and
insulated.
A) Cooled water temperature too low
See trouble 3
B) Cooled water flow capacity too low
See trouble 4
C) Clogged refrigerant filter
10. Low compressor suction
pressure
D) The thermostatic valve is not set properly
or is defective
Check the refrigerant filter
Check the thermostatic valve overheating is
correct; check the thermostatic element is not damaged
E) Refrigerant charge is insufficient
Check possible leakage and recharge
F) Discharge pressure too low See trouble 8
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