POLICY
Diagnosis of basic chiller faults.
PROCEDURE
CAUTION
· Always refer to operational manuals for specific plant.
· Chillers may be subjected to warranty. Inappropriate operation may result in void of warranty.
· Do not reset chillers without the express consent of the original supplier.
· Do not erase system computer diagnosis outputs in an attempt to re-set chillers. Such outputs are
useful for advanced system failure diagnosis.
Modern chillers are complex highly efficient machines which often run close to the critical limits of
refrigerant gases.
This procedure is not intended to be an exhaustive explanation rather a basis guide to common faults and
their fundamental diagnosis.
HP CUT OUT:
Chiller refrigeration circuits are subject to high pressures and temperatures. Operation of chillers outside
of normal operational parameters can cause serious damage to compressors, condensers and other
refrigeration circuit components.
To prevent damage to critical components, most chillers are fitted with safety cut outs. Cut outs are of the
manual or automatic re-set type.
High pressure in a refrigeration circuit is generally caused by either over charging of the circuit or an
inadequate condenser water supply or cooling tower failure. High pressure can also result where
extremes of outside air temperature and/or humidity.
Less likely causes include failure of thermal expansion valves or gross carry-over of lubrication oil.