Questions regarding the wiring of explosion-proof motors
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The factory has a hydrogen production workshop, and difficulties arose during the wiring of the motors. How should the distance between the galvanized steel pipe carrying the cable to the motor and the wiring box of the motor be handled? Is it necessary to use explosion-proof flexible hoses? If explosion-proof flexible hoses are used in all cases, and given that motors come in different sizes and models as well as cables of varying sizes, wouldn’t it be necessary to purchase explosion-proof flexible hoses of different sizes and with different connectors? That would be very troublesome! Can a plastic-coated metal hose be used, with both ends securely sealed using explosion-proof putty to achieve an explosion-proof effect? If you know of any relevant standards or specifications, I would be extremely grateful if you could give me some guidance!
It depends on the local requirements; if it can pass the inspection, that’s fine, otherwise one has to buy it. Our company does this, and it works
Are you just using plastic-coated metal hoses?
Check the local requirements; as long as it meets them, it’s fine. Some specifications require the use of explosion-proof flexible pipes, while others do not. If it’s necessary to add something from the steel pipe to the motor junction box, what about the cables in the cable tray?
No, just cover the steel pipe outlet with mud and that’s it
Generally, it works fine; it depends on what the local experts say. If it doesn’t work, one will have to spend more money
It is necessary to purchase explosion-proof flexible hoses of different sizes and with different connectors separately! ! ! ! ! ! ! ! ! ! ! ! ! !
Are the cables you use armored? For motors in explosion-proof areas, the junction boxes must be equipped with explosion-proof gaskets to provide explosion-proof sealing; therefore, the flexible tubing used from the conduit to the junction box serves primarily to protect the cable from mechanical damage. If it is a armored cable, there is no need to add a flexible tube. If it’s not armored, a flexible pipe with plastic coating will also work; some of our clients use this approach. As for the specifications, I haven’t found any detailed rules. For reference
No. Since the motor is located in a protected area, its connection pipes must be explosion-proof flexible connection pipes, and the explosion protection rating should be selected according to the protection level. The electrical junction box is explosion-proof, and its pre-installed wire outlet holes come in various thread sizes; you can consult the manufacturer for details. The thread specification of the explosion-proof hose fitting you choose should match that of the manufacturer’s products.
The motor’s armored flange allows for direct wiring, without the need for a flexible tube
You’re right; using explosion-proof mud will do. It also depends on the local inspection authorities – if they approve it, then it’s okay