Some knowledge points about explosion-proof motors

2021-02-19 12:34

Dust is particulate matter that can be suspended in the air or accumulate in layers. Depending on the severity of its combustion, it can be classified into two categories: explosive dust and combustible dust. In dusty environments, the reliability requirements for explosion-proof motor equipment are increasingly high.

Sealing structure characteristics of explosion-proof motors; the sealed type connects the explosion-proof motor between the inner and outer chambers, achieving dust prevention by adding gaskets. Gaskets should be made of asbestos board, rubber board, or other durable, high-quality materials, and should be suitable for the load conditions and expected operating life temperature of the electrical equipment; otherwise, it will affect the performance of the explosion-proof motor.

The sealing components of sealed dust-proof and explosion-proof motors mainly refer to the connections between the motor base and end cap, end cap and outer casing, base and junction box, box seat and box cover, etc. Due to the perimeter of the mating surface, the sealing requirements between the frame and the end cap are also very high. To achieve sealing performance, the gasket must have a certain elasticity. In order to maintain the stability of the bearing distance of the motor, there must be a positioning structure between the frame and the end cap, which cannot be positioned by the strength of the gasket. When the connecting bolts between the end cap and the base are tightened, the sealing gasket is compressed and thinned, the end cap moves inward, and the entire bearing chamber also moves inward, thus reducing the designed axial clearance and the axial clearance of the bearing. In severe cases, the bearing will jam. Even if the explosion-proof motor does not jam, it will inevitably cause high bearing noise, high bearing temperature, and short service life after operation.

Classification of Dust Explosion Hazardous Locations ： Before understanding dust-proof and explosion-proof motors, it is first necessary to know how to classify dust explosion hazardous locations. Dust explosion hazardous locations are divided into two zones according to the frequency and duration of explosive or combustible dust environments.

Selection of Dust Explosion-Proof Motors ： In order to operate normally in the above areas, the enclosures of dust explosion-proof motors are divided into two categories according to their ability to restrict dust. ： Dust-proof enclosure, enclosure protection level is IP6X ，marked as DT ；Dust-proof enclosure, enclosure protection level is IP5X ，marked as DP . When selecting explosion-proof motors, suitable explosion-proof motor types can be selected from two aspects. Correctly selecting a suitable explosion-proof motor is more helpful for the effective progress of the work.