Technical requirements for wire rope electric hoist

1、 Working environment conditions of wire rope electric hoist

1. The rated voltage of the main circuit of the electric hoist is single-phase or three-phase AC 110v660v, and the rated frequency is 50Hz or 60Hz. The voltage fluctuation range of the motor terminal shall not exceed ± 10% of the rated voltage, and the internal voltage drop of the electric hoist shall not exceed 5%.

2. The working environment temperature of electric hoist is generally - 20 ℃ ~ 40 ℃, and the working environment temperature of electric hoist for lifting molten metal is - 10 ℃ ~ 60 ℃.

3. When the maximum temperature is 40 ℃, the relative humidity shall not exceed 50%, and the electrical equipment shall be able to work normally. Higher humidity may be allowed at lower temperatures, for example, 90% at 20 ℃.

4. The altitude shall not exceed 1000m.

5. The operating conditions of the motor shall comply with the provisions in Chapter 6 and Chapter 7 of gb755-2008.

6. The normal use, installation and transportation conditions of electrical equipment shall comply with the provisions in Chapter 6 of gb14048.1-2012.

Dalian Jiali lifting rigging equipment Co., Ltd. note: in case of exceeding the above conditions, the user shall negotiate with the manufacturer.

2、 Basic requirements for wire rope electric hoist

The design of electric hoist shall meet the relevant provisions of GB / t3811, gb6067.1 and this part. JBff9008.1-2014

3、 Performance of wire rope electric hoist

1. The electric hoist of corresponding working level shall be reasonably selected according to the service level and load state level.

2. The structural type, basic parameters, performance and size of the electric hoist shall meet the design requirements.

3. The reducer shall not leak oil.

4. The hook shall rotate flexibly and can rotate 360 degrees in the horizontal plane..

5. When the hook is lowered and there is no other external force on the wire rope, the wire rope shall be discharged from the drum freely; When lifting and lowering the rated load, the angle between the center line of the wire rope and both sides of the center line of the spiral groove shall not be greater than 3.5. It shall be able to work normally.

6. When conducting static load test, the electric hoist shall be able to bear the test load of 1.25 times the rated lifting capacity. After the test, all stressed parts shall be free of cracks, permanent deformation and paint peeling, and all joints shall be free of looseness.

7. When conducting dynamic load test, the electric hoist shall be able to bear the test load of 1.1 times the rated lifting capacity. It shall work normally and brake reliably during the test.

8. The electric hoist with operating mechanism shall meet the following performance requirements under rated load:

a) There shall be no abnormality during operation:

b) There shall be no abnormality in the 1 / 200 climbing test:

c) The allowable deviation of operating speed shall be ± 15% of the nominal value (slow speed will not be assessed).

9. Under the rated load, the braking sliding amount shall not be greater than V / 100 (V is the distance of 1min stable lifting under the rated load), and shall not be greater than 200mm.

10. Under the condition of rated load and ± 10% fluctuation of motor terminal voltage, the motor and brake shall work normally.

11. The lifting height shall not be less than the nominal value.

12. The allowable deviation of lifting speed shall be ± 10% of the nominal value, and the allowable deviation of lowering speed shall be - 10% 25% of the nominal value (slow speed shall not be assessed).

13. The safety distance of the hook shall not be less than 100mm.

14. The energy effect of electric hoist shall comply with relevant regulations.

15. The rated lifting capacity of the electric hoist for lifting molten metal shall not be greater than 16t and the working level shall not be lower than M6.

4、 Safety and health

Safety protection device

1) The electric hoist shall be provided with the limit position limiter for lifting and lowering, and it can ensure that the power supply will be cut off automatically when the hook is lifted and lowered to the limit position, and the action in the opposite direction can be carried out at this time.

2) The electric hoist for lifting molten metal shall be provided with different types of double limit protection devices at the lifting limit position, and can control different electrical circuits.

3) The rated lifting capacity shall be marked at the eye-catching position of the hook group, and the hook mouth locking device shall be set. The electric hoist for lifting molten metal should not be equipped with locking device.

4) Electric hoist with rated lifting capacity of LT and above shall be equipped with lifting capacity limiter. When the actual lifting capacity exceeds 95% of the rated lifting capacity, the lifting capacity limiter should send an alarm signal (except for the automatic stop type): when the actual lifting capacity is between 100% and 110% of the rated lifting capacity, the lifting capacity limiter will work. At this time, the lifting power supply shall be automatically cut off, but the mechanism shall be allowed to move downward.

When the electric hoist is overloaded, the lifting weight limiter stops lifting. At this time, the lifting height of the load shall not exceed the distance of the nominal lifting speed ls. For the double speed electric hoist, the slow speed will not be assessed.

5) The electric hoist shall be provided with a normally closed service brake, and the braking safety factor of the brake shall meet the following requirements:

a) The working level is MS and below, and shall not be lower than 1.5;

b) The working level is M6 and above, and shall not be lower than 1.75.

When the electric hoist is used as the lifting mechanism to lift molten metal, the setting of its brake shall meet the following requirements:

a) When the rated lifting capacity is greater than 5T, the electric hoist shall be provided with a safety brake on the low-speed stage of the electric hoist in addition to a working brake;

b) When the rated lifting capacity is less than or equal to 5T, the electric hoist should be equipped with a safety brake on the low-speed stage of the electric hoist in addition to a working brake. Otherwise, the electric hoist should be designed as 1.5 times the rated lifting capacity.