10 · Important Safety Instructions · Dehumidifier 50, 35, 22 Pint
render the appliance safe for ammable refrigerants. This process might need to
be repeated several times. Compressed air or oxygen shall not be used for purging
refrigerant systems. For appliances containing ammable refrigerants, refrigerants
purging shall be achieved by breaking the vacuum in the system with oxygen-free
nitrogen and continuing to ll until the working pressure is achieved, then venting
to atmosphere, and nally pulling down to a vacuum. This process shall be repeated
until no refrigerant is within the system. When the nal oxygen-free nitrogen charge
is used, the system shall be vented down to atmospheric pressure to enable work to
take place. Ensure that the outlet for the vacuum pump is not close to any potential
ignition sources and that ventilation is available.
12. Charging Procedures
In addition to conventional charging procedures, the following requirements shall be
followed. Ensure that contamination of different refrigerants does not occur when using the
charging equipment. Hoses or lines shall be as short as possible to minimize the amount of
refrigerant contained in them.
Cylinders shall be kept in an appropriate position according to the instructions.
Ensure that the refrigeration system is earthed before charging the system with the
refrigerant. Label the system when the charging is complete (in case it has not been
labeled yet).
Extreme care shall be taken to avoid overlling the refrigeration system.
Prior to recharging the system, the pressure test with OFN must rst be conducted. The
system leak test shall be performed upon completion of charging, but should be done prior
to commissioning. A follow up leak test shall be carried out before leaving the site.
13. Decommissioning
Before carrying out this procedure, it is essential that the technician is completely familiar
with the equipment and all necessary details. It is good practice that all refrigerants be
recovered safely. Prior to carrying out this task, an oil and refrigerant sample shall be taken
in case analysis is required before reusing the reclaimed refrigerant. It is essential that
electrical power is available before this task commences.
a. Become familiar with the equipment and its operation.
b. Isolate the system electrically.
c. Before attempting the procedure, ensure that:
· Mechanical handling equipment is available, if required, for handling refrigerant
cylinders;
· Allpersonal protective equipment is available and being used correctly;
· The recovery process is always supervised by a competent person and recovery
equipment and cylinders conform to the required standards.
d. Pump down the refrigerant system, if possible.
e. If a vacuum is not possible, make a manifold so that refrigerants can be removed
from various parts of the system.
f. Make sure that the cylinder is situated on the scales before recovery takes place.
g. Start the recovery machine and operate in accordance with the manufacturer’s
instructions.
h. Do not overll the cylinders. (No more than 80% volume liquid charge).
i. Do not exceed the maximum working pressure of the cylinder, even temporarily.
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