ENG
NOTE
The use of silicon sealant may inhibit the effectiveness of some types of leak detection
equipment. Instrinsically safe components do not have to be isolated prior to working
on them.
11) 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. Intrinscially 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.
12) 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.
13) 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.
14) 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‐
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. 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 or extinguished. If a
leakage of refrigernat 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.
15) Removal and evacuation
When breaking into the refrigerant circuit to make repairs of 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:
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VIVAX