Singer SDHM-16L PURE DRY ION, Instruction Manual

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ENGLISH
conventional procedures shall be used. However, for fl ammable refrigerants it
is important that best practice is followed since fl ammability is a consideration.
The following procedure shall be adhered to:
• remove
refrigerant.
• purge the circuit with inert gas.
• Evacuate vacuum.
• purge with inert gas.
• open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders.
For appliances containing
fl ammable refrigerants the system shall be purged
with oxygen-free nitrogen to render the appliance safe for fl ammable refriger-
ants. This process may need to be repeated several times. Compressed air or
oxygen shall not be used for purging refrigerant systems.
For appliances containing
fl ammable refrigerants, refrigerants purging shall be
achieved by breaking the vacuum in the system with oxygen-free nitrogen and
continuing to
fi ll until the working pressure is achieved, then venting to atmos-
phere, and fi nally pulling down to a vacuum. This process shall be repeated
until no refrigerant is within the system. When the fi nal oxygen-free nitrogen
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 opera-
tions on the pipe-work are to take place.
Ensure that the outlet for the vacuum pump is not close to any potential ignition
sources and that
ventilation is 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
minimize the amount of refrigerant contained in them.
• Cylinders shall be kept in an appropriate position according to the instruc-
tions.
• Ensure that the refrigerating system is earthed prior to charging the sys-
tem with refrigerant.
• Label the system when charging is complete (if not already).
• Extreme care shall be taken not to over fi ll the refrigerating system.