Midea MAW User Manual page 8

8) Checks to the refrigerating equipment
When replacing electrical components, ensure they are suitable for their intended purpose and meet
the correct specifi cations. Always adhere to the manufacturer's maintenance and service guidelines. If
uncertain, seek guidance from the manufacturer's technical department. The following checks should be
performed for installations utilizing fl ammable refrigerants:
The refrigerant charge must align with the size of the room where refrigerant-containing parts are
installed. Ensure ventilation systems and outlets operate effectively and remain unobstructed. If using
an indirect refrigerating circuit, verify the presence of refrigerant in the secondary circuit. Equipment
markings must be visible and legible at all times; any illegible markings or signs should be promptly
corrected. Refrigeration pipes and components should be installed in locations unlikely to expose them
to corrosive substances, unless they are inherently corrosion-resistant materials or adequately protected
against corrosion.
9) Checks to electrical devices
Repair and maintenance of electrical components must begin with initial safety checks and thorough
inspection procedures. If a fault is identifi ed that could pose a safety risk, no electrical supply should be
connected to the circuit until the issue is resolved. If immediate correction of the fault isn't
feasible but operation must continue, a suitable temporary solution must be implemented. This action
should be promptly reported to the unit owner to ensure all parties are informed.
Initial safety checks shall include:
Ensure capacitors are discharged safely to prevent sparking. Ensure no live electrical components or
exposed wiring during charging, recovering, or purging the system. Verify continuity of earth bonding
throughout these procedures.
7. Sealed electrical components shall be replaced.
8. Intrinsically safe components must be replaced.
9. 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.
10. Detection of fl ammable refrigerants.
Under no circumstances should potential sources of ignition be used during the search for or detection
of refrigerant leaks. This includes avoiding the use of halide torches or any other detectors that utilize
naked fl ames.
The following leak detection methods are deemed acceptable for systems containing fl ammable
refrigerants. Electronic leak detectors shall be used to detect fl 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 confi rmed. Leak
detection fl 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 fl ames shall be removed/extinguished. If a refrigerant leak requiring brazing
is detected, all refrigerant must be recovered from the system, or isolated (using shut-off valves) in a part of
the system away from the leak. Removal of refrigerant shall be according to "Removal and evacuation".
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