CO/Tech MDDG-20DEN7-QA3 User Manual

7
ENGLISH
15. Removal and evacuation
When breaking into therefrigerant circuit to make repairs - or for any other purpose -
conventional procedures shall be used. However, it is important that best practice is followed
since flammability is aconsideration. Thefollowing procedure shall be adhered to:
• remove refrigerant;
• purge thecircuit with inert gas;
• evacuate;
• purge again with inert gas;
• open thecircuit by cutting or brazing.
Therefrigerant charge shall be recovered into thecorrect recovery cylinders. 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 this task. 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 close to any ignition sources
and there is aventilation available.
16. 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 charging
equipment. Hoses or lines shall be as short as possible to minimise 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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 practice that all 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 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.

CO/Tech MDDG-20DEN7-QA3 Specifications

General

Brand	CO/Tech
Model	MDDG-20DEN7-QA3
Category	Dehumidifier
Language	English