Repair of explosion-proof electric appliances and fixtures
Explosion-proof devices used in hazardous areas ( areas ) . Said explosive zone , wherein the process conditions can be released combustible gases in an amount such that they form with air explosive mixtures . There are several classes of premises on the grounds of explosion .
We consider the main features of repair explosion-proof devices and fixtures , set in the most dangerous areas on the conditions of the explosion. Repairs may only be carried out by repair units that are provided with the necessary special equipment , tool room, a skilled maintenance personnel and are authorized to perform repair of explosion-proof devices.
The principal terms of repair include:
– Increased demands on the quality of work performed,
– Strengthened standards rejection of damaged parts and components,
– Using only a material which provides structure ,
– Increased requirements for testing and inspection of the device is repaired .
Disassemble the equipment and fixtures necessary to very carefully , avoiding damage , especially surfaces ( marked ” explosion “). Do not apply strong impact and effort during removal. It is difficult to unscrew the fasteners must be pre- moistened with kerosene .
Fasteners after disassembly is recommended to screw into place in order to avoid losses. Parsed details note tags to permit assembly without errors on their installation .
Damaged parts replaced . When repairing is necessary to ensure maximum preservation of its factory settings , which until repairs should be known to service personnel according to the drawings and technical documents of the manufacturer .
Refurbished , re- produced or the number of parts taken from the parts must be inspected and tested in accordance with the relevant guidelines and methodology.
The necessary tests – electrical and the mechanical strength and overpressure – hold for all components regardless of whether they have been taken in the repair or replacement of , because when removing and transporting them to be damaged.
Special requirements for flameproof clean surfaces ( “explosion” ) , connections and values flameproof gaps.
Minor shell diameter of 2 mm and a depth of 1 mm, nicks, dents, found on the surfaces of the flanges or bores , remove foil lids solder POS -40 for steel parts , copper – for cast iron and plating – for aluminum alloys , cleaning pre- damaged areas to the metal shine. Lead is used for these purposes is not permitted.
Eliminating such mechanical damage by explosion protection on the surface are not allowed. The device or part of it in this case is rejected .
For devices whose contacts immersed in oil , it is necessary to monitor the oil level in the tank , the parameters for its physicochemical properties.
For inspection lamps are paying particular attention to the absence of cracks in the glass protective cap, molded case , packing nuts input device .
When disassembling the fixtures for the repair or lamp replacement , inspect and repair install the cartridge contacts and the ground connection of wires 4 and 5 , no shells or corrosion on the mating planes , check the rubber seals 2 , wire insulation 6. Replace damaged elements of the number of replacement or rebuild. Disassembly lights should be switched off at the mains if repair is associated with the replacement of lamps or in the repair shop, if they are to be overhauled.
To disassemble the use of special tools and perform it in the following sequence:
1. 1 key unscrew bolts that hold the push sleeve and remove it .
2 . Entry is removed from the socket rubber ring .
3 . The key unscrew the cap lamp 3 input device .
4 . Check the status of terminals and ground .
5 . Wrench screws holding the reflector and glass are the safety net .
6. Check the lamp.