Carrier QHC Series Service Manual page 8

earthed prior to charging the system with
refrigerant.

Label the system when charging is complete

(if not already).

Extreme care shall be taken not to overfill

the refrigeration system.

Prior to recharging the system it shall be

pressure tested with OFN. The system shall be
leak tested on completion of charging but prior
to commissioning. A follow up leak test shall be
carried out prior to leaving the site.
17. Decommissioning
Before carrying out this procedure, it is
essential that the technician is completely
familiar with the equipment and all its detail. It is
recommended good
refrigerants are recovered safely. Prior to the
task being carried out, an oil and refrigerant
sample shall be taken.
In case analysis is required 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
operation.
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

available and being used correctly;

the recovery process is supervised at all

times by a competent person;

recovery equipment and cylinders conform
to the appropriate standards.
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
accordance with manufacturer's instructions.
h) Do not overfill cylinders. (No more than 80 %
volume liquid charge).
practice that all
equipment is
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 cleaned and checked.
18. Labelling
Equipment shall be labelled stating that it has
been de-commissioned and emptied of
refrigerant. The label shall be dated and signed.
Ensure that there are labels on the equipment
stating the equipment contains flammable
refrigerant.
19. Recovery

When removing refrigerant from a system,

either for servicing or decommissioning, it is
recommended
refrigerants are removed safely.

When transferring refrigerant into cylinders,

ensure that only appropriate refrigerant
recovery cylinders are employed. Ensure that
the correct numbers of cylinders for holding the
total system charge are available. All cylinders
to be used are designated for the recovered
refrigerant and labelled for that refrigerant (i.e.
special cylinders for the recovery of refrigerant).
Cylinders shall be complete with pressure relief
valve and associated shut-off valves in good
working 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 flammable
refrigerants. In addition, a set of calibrated
weighing scales shall be available and in good
working order.

Hoses shall be complete with leak-free

disconnect couplings and in good condition.
Before using the recovery machine, check that
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good practice that all