Midea MP72SQWBA2RCM Owner's Manual page 9

WARNINGS (for using R32 refrigerant only)
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 a ected.
This shall include damage to cables, excessive number of connections, terminals
not made to original speci cation, damage to seals, incorrect tting of glands, etc.
Ensure that apparatus is mounted securely.
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 speci cations.
NOTE: The use of silicon sealant may inhibit the e ectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated prior
to working on them.
• 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 speci ed by the manufacturer. Other parts may
result in the ignition of refrigerant in the atmosphere from a leak.
• Cabling
Check that cabling will not be subject to wear, corrosion, excessive pressure,
vibration, sharp edges or any other adverse environmental e ects. The check shall
also take into account the e ects of aging or continual vibration from sources such
as compressors or fans.
• Detection of ammable 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.
• 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 con rmed. 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.
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