Johnson JDMV3 Serie Manual De Instrucciones página 206

The refrigerant charge shall be recovered into the correct recovery cylinders. For
appliances containing FLAMMBLE REFRIGERANTS, the system shall be "flushed"
with OFN to render the unit safe. This process may need to be repeated several
times. Compressed air or oxygen shall not be used for puring refrigerant systems.
For appliances containing FLAMMABLE REFRIGERANTS, flushing shall be
achieved by breaking the vacuum in the system with OFN and continuing to fill
until the working pressure is achieved, then venting to atmosphere, and finally
pulling down to a vacuum. This process shall be repeated until no refrigerant is
within the system. When the final OFN charge is used, the system shall be vented
down to atmospheric pressure to enable work to take place. This operation is
absolutely vital if brazing operations on the pipe-work are to take place.
Ensure that the outlet for the vacuum pump is not closed to any ignition sources
and there is ventilation available.
16. Charging procedures
In addition to conventional charging procedures, the following requirements shall
be followed:
 Works shall be undertaken with appropriate tools only (In case of uncertainty,
please consult the manufacturer of the tools for use with flammable refrige-
rants).
 Ensure that contamination of different refrigerants does not occur when u-
sing charging equipment. Hoses or lines shall be as short as possible to mini-
mize the amount of refrigerant contained in them.
 Cylinders shall be kept upright.
 Ensure that the refrigeration system is 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 sys-
tem shall be leak tested on completion of charging but prior to commis-
sioning. 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 practice that all refrigerants are recovered safely or safely vented (For
R290 refrigerant models only). 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 refrige-
rant cylinders;
 all personal protective equipment is 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.
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