Specialist’s Manual
Repair to intrinsically safe components
Do not apply any permanent inductive or capaci-
tance loads to the circuit without ensuring that this
will not exceed the permissible voltage and current
permitted for the equipment in use.
Intrinsically safe components are the only types that
can be worked on while live in the presence of a fl-
ammable atmosphere. The test apparatus shall be
at the correct rating.
Replace components only with parts specified by the
manufacturer. Other parts may result in the ignition
of refrigerant in the atmosphere from a leak.
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Cabling
Check that cabling will not be subject to wear, cor-
rosion, excessive pressure, vibration, sharp edges
or any other adverse environmental effects. The
check shall also take into account the effects of
aging or continual vibration from sources such as
compressors or fans.
●
Detection of flammable refrigerants
Under no circumstances shall potential sources of
ignition be used in the searching for or detection of
refrigerant leaks. A halide torch (or any other detec-
tor using a naked flame) shall not be used.
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Leak detection methods
Leak detection fluids are suitable for use with most
refrigerants but the use of detergents containing ch-
lorine shall be avoided as the chlorine may react
with the refrigerant and corrode the copper pipe-work.
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Decommissioning
Before carrying out this procedure, it is essential that
the technician is completely familiar with the equip-
ment and all its detail. It is recommended good pr-
actice that all refrigerants are recovered safely.
Prior to the task being carried out, an oil and refri-
gerant sample shall be taken in case analysis is re-
quired prior to re-use of reclaimed refrigerant. It is
essential that electrical power is available before
the task is commenced.
a) Become familiar with the equipment and its opera-
tion.
b) Isolate system electrically.
c) Before attempting the procedure, ensure that:
– mechanical handling equipment is available, if
required, for handling refrigerant cylinders;
– all personal protective equipment is available
and being used correctly;
– the recovery process is supervised at all times
by a competent person;
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Labelling
d) Pump down refrigerant system, if possible.
e) If a vacuum is not possible, make a manifold so
that refrigerant can be removed from various parts
of the system.
f) Make sure that cylinder is situated on the scales
before recovery takes place.
g) Start the recovery machine and operate in accor-
dance with manufacturer's instructions.
h) Do not overfill cylinders. (No more than 80% vo-
lume liquid charge).
i) Do not exceed the maximum working pressure of
the cylinder, even temporarily.
j) When the cylinders have been filled correctly and
the process completed, make sure that the cylinders
and the equipment are removed from site promptly
and all isolation valves on the equipment are closed
off.
k) Recovered refrigerant shall not be charged into
another refrigeration system unless it has been clean-
ed and checked.
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Recovery
When removing refrigerant from a system, either
for servicing or decommissioning, it is recommend-
ed good practice that all refrigerants are removed
safely.
When transferring refrigerant into cylinders, ensure
that only appropriate refrigerant recovery cylinders
are employed. Ensure that the correct number of cy-
linders for holding the total system charge are av-
ailable. All cylinders to be used are designated for
the recovered refrigerant and labelled for that refri-
gerant (i.e. special cylinders for the recovery of refri-
gerant). Cylinders shall be complete with pressure-re-
lief valve and associated shut-off valves in good work-
ing order. Empty recovery cylinders are evacuated
and, if possible, cooled before recovery occurs.
The recovery equipment shall be in good working
order with a set of instructions concerning the
equipment that is at hand and shall be suitable for
the recovery of all appropriate refrigerants includ-
ing, when applicable, flammable refrigerants. In ad-
●
– recovery equipment and cylinders conform to
the appropriate standards.
27
Equipment shall be labelled stating that it has been
de-commissioned and emptied of refrigerant. The
label shall be dated and signed. For appliances con-
taining flammable refrigerants, ensure that there are
labels on the equipment stating the equipment con-
tains flammable refrigerant.
