1. The electric hoist should be reasonably selected according to the level of use and load status. The working level of the electric hoist hoisting mechanism is divided into 8 levels from M1 to M8 according to the load state level, the mechanism load spectrum coefficient, the use level and the total use time.
2. The structure, basic parameters, performance and size of the electric hoist should meet the design requirements.
3. The electric hoist reducer should not leak oil.
4. The hook of the electric hoist should rotate flexibly and can rotate 360° in the horizontal plane.
5. When the hook of the electric chain hoist China is lowered and the wire rope has no other external force, the wire rope should be freely discharged from the drum; when lifting and lowering the rated load, the angle between the wire rope centerline and the two sides of the spiral groove centerline should not be greater than 3.5° should work normally.
6. When the electric hoist does the static load test, it should be able to bear the test load of 1.25 times the rated lifting capacity. After the test, there should be no cracks, permanent deformation and peeling of paint on the load-bearing parts, and there should be no looseness at the joints.
7. When the electric hoist is subjected to the dynamic load test, it should be able to withstand a test load of 1.1 times the rated lifting capacity. During the test, it should work normally and the braking is reliable. After the test, there should be no cracks, permanent deformation and peeling of paint on the load-bearing parts, and there should be no looseness at the joints.
8. The electric hoist with running mechanism shall meet the following performance requirements under rated load:
(1) There should be no abnormal phenomena during operation:
(2) There should be no abnormal phenomenon in the 1/200 climbing test;
(3) The allowable deviation of the running speed should be ±15% of the nominal value (slow speed is not checked).
9. Under the rated load of the electric hoist, the braking sliding amount should not be greater than v/100 (v is the distance for stable lifting in 1min under the rated load), and should not be greater than 200mm.
10. Under the condition of rated load and voltage fluctuation of motor terminal ±10%, the work of motor and brake should be normal.
11. The lifting height of the electric hoist should not be less than the nominal value.
12. The allowable deviation of the hoisting speed of the electric hoist should be 10% of the nominal value, and the allowable deviation of the descending speed should be -10%~25% of the nominal value (slow speed is not assessed).
13. The safety distance of the hook of the electric hoist should not be less than 100mm.
14. The rated lifting weight of the electric hoist for lifting and transporting molten metal should not be greater than 16t, and the working level should not be lower than M6.
15. The gap between the inner side of the rim of the electric hoist wheel and the edge of the lower flange of the I-beam track should be 3mm~5mm.