Instruction manual

K4, K6, K9 series chillers – Installation and Operation manual
Issue 10.33
Page 14
4.1 – Troubleshooting
This section outlines common refrigeration system faults. In most cases a refrigeration
service technician will have to carry out the necessary repairs as these involve specialist
skills and tools. It is very important that the prime cause of the problem is identified and
rectified.
Whenever service or repair work is carried out on the refrigeration system, the refrigerant
should be pumped into a recovery vessel if it cannot be held in the system receiver. If the
refrigerant is uncontaminated, it can be re-used. Otherwise, it should be returned to the
refrigerant manufacturer for recycling. Legally, companies other than refrigerant
manufacturers may recycle refrigerant, but checks should be made to ensure the quality of
the recycled product is acceptable. Refrigerants should not be vented to the atmosphere
because of their unacceptably high ozone depletion potentials and greenhouse strengths.
The tables below address each of the symptoms listed. The left hand column gives the
possible causes, the next column identifies checks that should be carried out and the right
hand column identifies actions, which should be taken. The shaded checks and actions are
those, which should only be carried out by a refrigeration service technician, and give an
indication to the end user of the type of rectification necessary. Unshaded checks and
actions are those, which the end user can undertake. The list is not exhaustive, but covers
the most common problems encountered in commercial refrigeration.
Symptom: Chiller too warm
Cause…
Check…
Action…
Compressor not running
Power on?
Switch on
Compressor failed?
Compare measured motor
winding resistances against
manufacturer’s values
Compressor start/run relay or
capacitor failed?
Find reason and rectify fault
Compressor tripped on controls
or pressure switches?
Check high/low pressure trips and
fluid level before repairing wiring
continued…