Topic: Do You Know the Overload Protection of Electric Chain Hoist
Electric chain hoist has a wide range of applications. It is currently active in the market and is deeply loved by users. It is used in many fields such as chemical mining, construction, logistics and so on to lift, lower and carry heavy objects, bulk materials and make heavy objects, bulk materials are moved horizontally and vertically within a short distance. Lifting is an indispensable job in the production process, and electric chain hoist is the top beam of the lifting and handling equipment. The main body of the running electric chain hoist is suspended on a traveling trolley, and the trolley travels along the I-beam of the crane beam to perform in-position operations.
During the operation of the electric chain hoist, if the long-term load is too large, the operation is frequent, or the short-phase operation, etc., the current of the electric chain hoist motor may exceed its rated value. Sometimes the leakage circuit breaker will not trip in this case, which will eventually cause the motor windings to overheat, the temperature exceeds the allowable temperature rise, damage the insulation, affect the service life of the electric chain hoist, and even burn the motor. The electric chain hoist needs to be protected against overload.
Overload protection of electric chain hoists is often carried out by thermal relays. The heating elements of thermal relays are connected in series in the two-phase main circuit of the control circuit. The normally closed contacts are installed in the control circuit. Due to overload or other reasons, the current exceeds the rated value. When the heating element is heated and bent after a period of time, the normally closed contact connected in series in the control circuit is disconnected, the control circuit is cut off, the coil of the contactor is de-energized, and the main contact is disconnected. To the role of overload protection.
Overload protection is a powerful guarantee for the smooth progress of the lifting work. It is to prevent the motor from overheating and reducing its performance, thereby affecting the normal service life of the electric chain hoist. A qualified electric chain hoist with guaranteed quality must be equipped with an overload protection device, which will give a booster to those struggling on the front line of lifting.