How to detect whether the purchase of qualified electric hoist

For now, electric  wire rope hoist  and other products on the market increasing variety of standard models, more unscrupulous traders refurbished goods traded, the most lifting equipment, the importance of safety can be imagined, then how to detect whether we are qualified to buy electric hoist You can be judged according to the following conditions hoist whether the target:

1, under the hook devices should hoist electric hoist rated capacity marked words and content, under the direction of the hook to be able to rotate 360 degrees and flexible steering.
2, if the electric chain  lever hoist, lifting chain then it should not be less than GB/T10051.1 requirements. Lifting chain guide should be installed on the chain and sprockets and cruises normal lifting engagement play a supporting role. Lifting chain from one end of the force shall be provided to prevent the crane from the lifting chain sprocket overwinding limiting device.
3, wire rope electric hoist electric hoist to adopt cone. Electric chain hoist motors to AC induction motor. Thermal insulation of the motor mechanism is not less than B grade classification. Motor protection and other provisions not less than GB/T4942.1 IP rating. 6 electric chain hoist motor winding on the metal casing shall withstand withstand voltage test 1 minute without the risk of insulation breakdown.
4, for the rated power less than 1.1KW motor,chain block leakage current during the test should not exceed 10 mA, for rated power greater than 1.1KW motor, leakage current during the test shall not exceed 20 mA.
5, at rated voltage, rated frequency and no-load state, the three-phase motor phase current in any one phase and three phase deviation should be less than the average of the three-phase average.