Tesla TT22EXC1-0732IA Руководство по эксплуатации онлайн [62/64] 771776

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supply to equipment during servicing, then a permanently operating form of leak detection shall be located at

the most critical point to warn of a potentially hazardous situation.

2. Particular attention shall be paid to the following to ensure that by working on electrical components, the

casing is not altered in such a way that the level of protection is affected. This shall include damage to cables,

excessive number of connections, terminals not made to original specification, damage to seals, incorrect

fitting of glands, etc.

Ensure that apparatus is mounted securely.

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.

19. 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.

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. Oxygen free

nitrogen (OFN) shall then be purged through the system both before and during the brazing process.

- 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