Inspection on Maintenance Environment
Maintenance Site Requirements
Leak Detection Methods
Safety Principles
9
Before operation, the refrigerant leaked in the room is not allowed.
The area of the room in which maintenance is made shall be in line with this manual.
Continuous ventilation shall be maintained during maintenance.
Open fire or high-temperature heat source higher than 548 degree which can easily give birth to open fire is not allowed
inside the room within the maintenance area.
During maintenance, the phones and the radioactive electronics of all the operators inside the room must be powered off.
One dry powder or carbon dioxide extinguisher shall be equipped inside the maintenance area, and the extinguisher must
be under available state.
The maintenance site shall be provided with favorable ventilation and must be flat. Arrangement of the maintenance site
inside the basement is not allowed.
Welding zone and non-welding zone shall be divided at the maintenance site, and shall be clearly marked. A certain safety
distance must be guaranteed between the two zones.
Ventilators shall be installed at the maintenance site, and exhaust fans, fans, ceiling fans, floor fans and dedicated exhaust
duct can be arranged, to meet the requirements of ventilation volume and uniform exhaust, and to avoid accumulation of
refrigerant gas.
Leak detection equipment for flammable refrigerant shall be equipped, with relevant management system being established.
Whether the leak detection equipment is under available state shall be confirmed before maintenance.
Sufficient dedicated vacuum pumps of flammable refrigerant and refrigerant charging equipment shall be equipped, with
relevant management system for maintenance equipment being established. It shall be guaranteed that the maintenance
equipment can only be used for vacuumizing and charging of one type of flammable refrigerant, and mixed usage is not
allowed.
The master power switch shall be arranged outside the maintenance site, with protective (anti-explosive) device being
equipped.
Nitrogen cylinders, acetylene cylinders and oxygen cylinders shall be placed separately. The distance between the gas
cylinders above and the working area involved in open fire shall be at least 6m. The anti-backfire valve shall be installed for
the acetylene cylinders. The color of the acetylene cylinders and oxygen cylinders installed shall meet the international
requirements.
The warning sign of " No Fire" ,"No Smoking", or"Anti static"shall be arranged inside the maintenance area.
Fire control device suitable for electric appliance such as the dry powder extinguisher or carbon dioxide extinguisher shall
be equipped, and shall always be under the available state.
The ventilator and other electrical equipment at the maintenance site shall be relatively fixed, with standardized pipe
routing. Temporary wires and sockets at the maintenance site are not allowed.
The environment in which the refrigerant leakage is checked shall be free from potential ignition source. Leak detection with
halogen probes (or any other detector with open fire) shall be avoided.
For the system containing flammable refrigerant, leak detection may be realized with electronic leak detection equipment.
During leak detection, the environment in which the leak detection equipment is calibrated shall be free from refrigerant. It
shall be guaranteed that the leak detection equipment will not become potential ignition source, and is applicable to the
refrigerant to be detected. 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.
The fluid used for leak detection shall be applicable to most of the refrigerant. The use of chlorine-containing solvent shall
be avoided, to avoid chemical reaction between chlorine and refrigerant and corrosion to copper pipelines.
In case leakage is suspected, the open fire at the site shall be evacuated or be put out.
In case welding is required at the leakage position, all the refrigerants shall be recovered, or be isolated at a position far
from the leak point with a stop valve. Before and during welding, the whole system shall be purified with OFN.
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.
