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WARNINGS (for using R290/R32 refrigerant only)
Page 10
Ensure that seals or sealing materials have not degraded such that they no longer serve
the purpose of preventing the ingress of ammable atmospheres. Replacement parts
shall be in accordance with the manufacturer's specications.
NOTE: The use of silicon sealant may inhibit the eectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated prior to
working on them.
8.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. Intrinsically safe components are the only types that can be worked on
while live in the presence of a ammable atmosphere. The test apparatus shall be at the
correct rating.Replace components only with parts specied 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 eects. The check shall also take into
account the eects 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 ame)
shall not be used.
11.Leak detection methods
The following leak detection methods are deemed acceptable for systems containing
ammable refrigerants. Electronic leak detectors shall be used to detect ammable
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 conrmed. Leak detection uids 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
ames 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 o 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.
12.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 ammability is a consideration. Opening of the refrigeration systems shall
not be done by brazing. The following procedure shall be adhered to:
Remove refrigerant;
Purge the circuit with inert gas;
Evacuate;
Purge again with inert gas;
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