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WARNING
(For using R290/R32 refrigerant only)
8. Intrinsically safe components must be replaced.
Do not apply any permanent inductive or capacitance loads to the circuit without ensuring that
this will not exceed the permissible voltage and current permitted for the equipment in use.
Intrinsically safe components are the only types that can be worked on while live in the presence
of a flammable atmosphere.
The test apparatus shall be at the correct 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.
9. Cabling
Check that cabling 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.
10. Detection of flammable refrigerants
Under no circumstances shall potential 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.
The following leak detection methods are deemed acceptable for systems containing flammable
refrigerants. Electronic leak detectors shall be used to detect flammable refrigerants, but 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 pipe-work. 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 refrigerant shall be recovered
from the system, or isolated (by means of shut off valves) in a part of the system remote from the
leak.
Removal of refrigerant shall be according to Removal and evacuation.
11. 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 best practice is
followed since flammability is a consideration. The following procedure shall be adhered to:
-Safely remove refrigerant following local and national regulations;
-Evacuate;
-Purge the circuit with inert gas (optional for A2L);
-Evacuate (optional for A2L);
-continuously flush or purge with inert gas when using flame to open circuit; and
-open the circuit.
The refrigerant charge shall be recovered into the correct recovery cylinders if venting is not
allowed by local and national codes. For appliances containing flammable refrigerants, the system
shall be purged with oxygen-free nitrogen flammable refrigerants. This process might compressed
air or oxygen shall not be used for purging refrigerant systems.
For appliances containing flammable refrigerants, refrigerants purging shall be achieved by
breaking the vacuum in the system with oxygen-free nitrogen and continuing to fill until the
working pressure is achieved, then venting to atmosphere, and finally pulling down to a vacuum
(optional for A2L). This process shall be repeated until no refrigerant is within the system (optional
for A2L). When the final oxygen-free nitrogen charge is used, the system shall be vented down to
atmospheric pressure to enable work to take place. The outlet for the vacuum pump shall not be
close to any potential ignition sources, and ventilation shall be available.
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