IRP U-SHAPE Series, Руководство пользователя

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rating. Replace components only with parts specified by the manufacturer. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
Wiring
Ensure the wiring will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any other
adverse environmental effects. The check shall also take into account the effects of aging or continual vibration from
sources such as compressors or fans.
Detection of flammable refrigerants
Under no circumstances shall potentially sources of ignition be used in the searching for or detection of refrigerant
leaks. A halide torch (or any other detector using a naked flame) shall not be used.
Leak detection methods
The following leak detection methods are deemed acceptable for all refrigerant systems. Electronic leak detectors may
be used to detect refrigerant leaks but, in the case of FLAMMABLE REFRIGERANTS, the sensitivity may not be
adequate, or may need re-calibration. (Detection equipment shall be calibrated in a refrigerant free area.) Ensure that
the detector is not a potential source of ignition and is suitable for the refrigerant used. Leak detection equipment shall
be set at a percentage of the LFL of the refrigerant and shall be calibrated to the refrigerant employed, and the
appropriate percentage of gas (25% maximum) is confirmed.
Leak detection fluids are suitable for use with most refrigerants but the use of detergents containing chlorine shall be
avoided as the chlorine may react with the refrigerant and corrode the copper pipework.
If a leak is suspected, all naked flames shall be removed/extinguished.
If a leakage of refrigerant is found which requires brazing, all of the refrigerants shall be recovered from the system, or
isolated (by means of shut off valves) in a part of the system remote from the leak. For appliances containing
FLAMMABLE REFRIGERANTS, oxygen free nitrogen (OFN) shall then be purged through the system both before and
during the brazing process.
Removal and evacuation
When breaking into the refrigerant circuit to make repairs
– or for any other purpose – conventional procedures shall
be used. However, for flammable refrigerants it is important that the best practice is followed since flammability is a
consideration.
Opening of the refrigeration systems shall not be done by brazing. 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. For appliances containing FLAMMABLE
REFRIGERANTS, the system shall be “flushed” with oxygen free nitrogen to render the unit safe. This process may
need to be repeated several times. Compressed air or oxygen shall not be used for purging 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 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 that ventilation is available.
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 upright.
Ensure that the refrigeration system is grounded prior to charge the system with refrigerant.
Label the system when charging is completed.
Extreme care shall be taken not to overfill the refrigeration system.
Prior to recharging the system, it shall be pressure tested with the appropriate purging gas. 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 leave the
site.