Precautions when wiring the explosion-proof motor

How to connect the explosion-proof motor

The explosion-proof motor wiring should be in the special junction box. The junction box must also be equipped with rubber seals, JBQ motor lead wires and other special explosion-proof motor parts.
Precautions when wiring the explosion-proof motor:
1. Check the clearance and creepage distance after the junction box is installed: 380/660V minimum clearance 10mm, creepage distance minimum 18mm. The minimum electrical clearance of 1140V is 18mm, and the creepage distance is a minimum of 30mm.
2. The incoming line of the junction box is sealed by pressing the rubber ring. The weakness of this structure is the aging of the rubber ring, the elastic failure, and the matching of the cable and the rubber ring is inconsistent.
3. For the junction box of the double outlet, the unused outlet should be blocked with a metal seal of not less than 2mm. The outer diameter of the metal seal should be similar to the inner diameter of the outlet of the inlet and outlet device to ensure the pressure or pressure. The tightening nut evenly presses the seal to achieve a reliable seal.
One of the main causes of various failures of explosion-proof motors is insulation and moisture. For example, in the Lviv-Warrensk Coal Mine, a motor for a face-to-face scraper conveyor with a production capacity of more than 1,000 tons in the day and night, the failure of the stator winding insulation resistance due to moisture and water droplets in the motor cavity is faulty. 45.7% of the total.
Therefore, closed-structure electrical equipment is not sufficient in many cases to protect it from adverse climatic factors. Therefore, there should be some special equipment in the electrical equipment enclosure to ensure that the climatic conditions are improved. It must include an air humidity regulator that reduces the relative humidity and humidity of the air in the enclosure, and occasionally drops moisture from the enclosure and prevents moisture from being drawn through the bearings and seals.


Use and maintenance considerations

(1) It should be noted that the type of explosion-proof motor is selected according to the environment of use.
(2) Set short-circuit, overload, overheating, and lack of equal protection in strict accordance with the requirements, and regularly check these protective devices to ensure their effectiveness.
(3) It is strictly forbidden for non-professionals to remove any part of the motor.
(4) Connect the power cord as follows: After removing the junction box cover, unscrew the wiring hopper, take out the rubber washer in the inlet of the terminal block, and put the two parts on the cable.
Should pay attention to:
The inner hole of the rubber gasket must be the same as the outer diameter of the cable. There must be no large gap. Otherwise, the rubber gasket and the cable cannot form a seal when the terminal is compressed, so that when the junction box explodes, it will cause an explosion outside the motor. , thus losing the flameproof effect.
The cable is introduced into the box from the junction box of the junction box, and the three strands of the core wire are respectively wound on the respective binding posts (the grounding core wire is also wound on the grounding screw), and each core wire must be rounded. Press the ground plate into the two bow washers and tighten the stud nuts.
After the cable is connected, install the rubber gasket. Install the terminal block and tighten the screws so that the end face of the terminal is pressed against the rubber ring to fully tighten the cable.(5) If disassembly and assembly is required, special attention should be paid to protecting the explosion-proof surface and windings from bumps. If multiple units are disassembled at the same time, the removed parts should be stored separately and not allowed to be mixed. If the removed parts are to be left for a while, the necessary anti-rust treatment should be applied to the explosion-proof surface.

Post time: Oct-28-2019

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