For the dynamic braking performance test of the safety brake of the ratchet and pawl of the wire rope electric hoist, the following are the detailed test contents and steps:

Test purpose:

Evaluate the response speed, braking effect, and dynamic stability of the ratchet and pawl safety brake in emergency braking situations to ensure reliable safety protection during lifting operations.

Test parameters:

Trigger speed: refers to the linear speed of the steel wire rope winding out of the drum when the drum exceeds the rated lifting speed and drops, causing the ratchet and pawl to trigger engagement.

Trigger time and braking time: the time from the acceleration of the braking motor to the engagement of the ratchet and pawl (trigger time), as well as the time from the triggering of the ratchet and pawl to the decrease of the motor speed to 0 (braking time).

Testing method:

Trigger speed detection:

In the unloaded state, accelerate the lifting motor of the electric hoist above the fundamental frequency of 50Hz, continuously measure the speed when the ratchet and pawl trigger engagement three times, and take the average value.

Under load conditions, the triggering speed can also be obtained through a fall test.

Trigger and stop time detection:

Set a timer in the PLC program to start timing when the motor starts rotating, and terminate timing when the electrical switch of the ratchet brake acts, obtaining the trigger time.

The timing starts when the electrical switch of the ratchet brake is triggered, and ends when the motor speed reaches 0, obtaining the stopping time. Measure continuously three times and take the average value.

Test equipment:

Electric hoist and its control system

Timer or PLC program

Human computer interaction display screen (used to display and record test data)

Necessary testing fixtures and sensors

Notes:

Before starting the test, ensure that the electric hoist is in good working condition and conduct necessary pre checks.

During the testing process, safety operating procedures should be strictly followed to ensure the safety of personnel and equipment.

Test data should be accurately recorded and subjected to reasonable data analysis and processing.

Testing standards and requirements:

Determine the qualified range of triggering speed, triggering time, and braking stop time of the brake according to relevant national and international standards.

Ensure that the brake can respond quickly and effectively during the testing process, and reduce the speed of the electric hoist to 0 within the specified time.

Test significance:

Dynamic braking performance testing is one of the important means to evaluate the safety performance of electric hoists, and its results directly affect the safety and efficiency of lifting operations.

Through testing, problems with the brakes can be identified in a timely manner, and corresponding measures can be taken to repair or improve the reliability and safety of the equipment.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment