INVENTOR ΑΤΜ-25L Manuel D'utilisateur page 26

10. Repair to intrinsically safe components
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.
11. 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 leaks. A halide torch (or any other detector using a
naked flame) shall not be used
12. 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.
13. Leak detection methods
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-calibrated.(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 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
both before and during the brazing process.
14. 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 processing 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 ventilation available.
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EN