etc.
Make sure that the unit is mounted safely.
Ensure that the joints or sealing materials have not degraded to the point of no longer preventing the penetration of
flammable atmospheres. Spare parts must comply with the manufacturer's specifications,
NOTE: The use of a silicone sealant can inhibit the effectiveness of certain types of leak detection equipment. Intrinsically
safe components do not have to be isolated before undergoing a procedure.
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Repair of intrinsically safe components
Do not apply inductive loads or permanent capacities to the circuit without ensuring that it will not exceed the permissible
voltage and current allowed for the equipment used.
Intrinsically safe components are the only types that can be worked on when they are energized in a flammable
atmosphere. The test equipment must have the correct rated characteristics.
Replace components only with parts specified by the manufacturer. Other parts can cause the refrigerant to ignite in the
atmosphere as a result of a leak.
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Cabling
Check that the wiring will not be subjected to wear, corrosion, excessive pressure, vibration, sharp edges or any other
adverse environmental effects. The verification must also take into account the effects of aging or continuous vibration
from sources such as compressors or fans.
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Detection of flammable refrigerants
Under no circumstances should potential ignition sources be used to search for or detect refrigerant leaks. A haloid lamp
(or any other detector using an open flame) must not be used.
Leak detection methods
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The following leak detection methods are considered acceptable for systems containing flammable refrigerants.
Electronic leak detectors must be used to detect flammable refrigerants, but their sensitivity may not be adequate or may
require recalibration. (Detection equipment must be calibrated in an area without refrigerant.) Ensure that the detector is
not a potential source of ignition and is suitable for the refrigerant used. The leak detection equipment must be set to a
percentage LFL of the refrigerant and must be calibrated to the fluid used and the appropriate percentage of gas
(maximum 25%) is confirmed.
Leak detection fluids are suitable for use with most refrigerants, but the use of detergents containing chlorine should be
avoided as chlorine can react with the refrigerant and corrode the copper piping.
In the event of a suspected leak, all open flames must be eliminated/extinguished.
If a refrigerant leak is found and brazing is required, all the refrigerant in the system must be recovered or isolated (by
means of shut-off valves) in a part of the system remote from the leak. The oxygen-free nitrogen must then be purged
through the system both before and during the brazing process.
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Removal and evacuation
When working on the refrigerant circuit for repairs - or for any other purpose - conventional procedures must be used.
However, it is important to follow best practice as flammability is a concern. The following procedure must be followed:
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