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Safety Principles
• The power supply should be cut off before the maintenance.
• During product maintenance, favorable ventilation shall be guaranteed at the maintenance site, and the close of
all the doors/windows is not allowed.
•
Operation with open fire is not allowed, including welding and smoking. The use of phones is also not allowed.
The user shall be informed that cooking with open fire is not allowed.
• During maintenance in a dry season, when the relative humidity is less than 40%, anti-static measures shall be
taken, including the wearing of cotton clothes and cotton gloves.
•
In case the leakage of flammable refrigerant is identified during maintenance, forced ventilation measures shall
be taken immediately, and the source of leak shall be plugged.
• In case the product damaged must be maintained by disassembling the refrigeration system, the product must be
delivered to the maintenance point. Welding of refrigerant pipelines at the user's site is not allowed.
•
During maintenance, in case re-treatment is required due to lack of fittings, the air conditioner shall be reset.
• The refrigeration system must be safely earthed in the whole course of maintenance.
• For the door-to-door service with refrigerant cylinders, the refrigerant charged inside the cylinder cannot
exceed the specified value. The cylinder placed in vehicles or at the installation/maintenance site shall be fixed
perpendicularly and be kept away from heat sources, ignition source, source of radiation and electric appliance.
Maintenance Requirements
• Before the refrigeration system is operated, the circulating system shall be cleaned with nitrogen. Afterwards,
the outdoor unit shall be vacuumized, the duration of which cannot be less than 30 minutes. Finally, 1.5~2.0MPa
OFN shall be used for nitrogen flushing (30 seconds~1 minute), to confirm the position requiring treatment.
Maintenance of the refrigeration system is only allowed after the residual gas of flammable refrigerant is removed.
• During the use of refrigerant charging tools, cross contamination of different refrigerants shall be avoided. The
total length (including the refrigerant pipelines) shall be shortened as much as possible, to reduce the residual of
refrigerant inside.
•
The cylinders of refrigerant shall be kept upright, and be fixed.
• After maintenance of the refrigeration system, the system shall be sealed with a safe manner.
• The maintenance in progress shall not damage or lower the original class of safety protection of the system.
Maintenance of Electrical Components
• Partial of the electrical component under maintenance shall be subject to inspection on refrigerant leakage with
dedicated leak detection equipment.
• After the maintenance, the components with safety protection functions cannot be disassembled or removed.
• During the maintenance of sealing elements, before opening the seal cover, the air conditioner shall be powered
off first. When power supply is required, continuous leak detection shall be carried out at the most dangerous
position, to avoid potential risks.
• During maintenance of electrical components, the replacement of enclosures shall not affect the level of
protection.
• After maintenance, it shall be guaranteed that the sealing functions will not be damaged or the sealing materials
will not lose the function of preventing the entry of flammable gas due to aging. The substitute components shall
meet the recommended requirements of the air conditioner manufacturer.
Maintenance of Intrinsically Safe Elements
•
The intrinsically safe element refers to the components working continuously inside flammable gas without any
risks.
• Before any maintenance, leak detection and inspection on earthing reliability of the air conditioner must be carried
out, to ensure no leakage and reliable earthing.
• In case the allowable voltage and current limit may be surpassed during the service of the air conditioner, any
inductance or capacitance cannot be added in the circuit.
• Only the elements appointed by the air conditioner manufacturer can be used as the parts and components
replaced, or otherwise a fire or explosion may be triggered in case of refrigerant leakage.
• For the maintenance not involved in system pipelines, the system pipelines shall be well protected, to ensure that
no leakage will be caused due to maintenance.
• After maintenance and before test run, the air conditioner must be subject to leak detection and inspection on
earthing reliability with leak detection equipment or leak detecting solution. It shall be guaranteed that the startup
inspection is carried out without leakage and under reliable earthing.
