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How to make inspection on power tool

Power tool is powered by electric motor or electromagnet, through the transmission mechanism to drive the work head of a mechanized tool, is an indispensable necessity in human daily production and life, because it is related to the safety of life, therefore, the inspection and testing of power tools is particularly important. So how to make inspection on power tool?


This article will give you a detailed description of the power tool inspection methods and precautions.


First, the inspection methods and standards of power tools


(i) Appearance inspection


1. Newly purchased electric appliances should first check whether the manufacturer's qualification, nameplate number, production date, product quality inspection certificate, etc. are fully standardized


2. Protect the ground wire or ground zero wire correctly, secure and reliable


3. Power cord, power plug is intact, power cord with mufti-stranded copper core and rubber sheath soft cable.


For Class I tool, single power supply should be three-core, three-power use of four-core cable.


4. Power switch action is normal, flexible, no defect, cracking


5. The housing, handle, no cracks and damaged mechanical protection are intact


6. Tool rotation part rotation flexible, brisk, no blocking phenomenon


7. Leak protection device is intact


8. Power-on airborne check, its rotation is normal, no sound.


(ii) Measurement of insulation resistance (Mega-European table method)

Measurement method: the bi-euro and ground wire, zero wire and ground wire are used to measure the insulation resistance (ground wire color is green and yellow two-color wire, zero line is light blue wire);


The shake handle should read the values when the slow and fast finally achieves uniform stability (approximately 120 revolutions per minute).


Second, the power tool inspection process


1. Determine the number of products


2. Proofreading the positive side hoe


3. Check the size, printing and material quality of the carton


4. Check the text, barcode, printing, color, certification mark, material quality and packaging method, such as blow molding box, check to show color, latch, material quality


5. Check that the accessories are complete, the function and appearance are intact, the instructions


6. Check that the pattern color of the box matches the color of the power tool


7. Designated sampling according to AQL standard (L-1, CRI s0, MAJ s 1.5, MIN s 4.0)


8. Run the machine for 15 minutes to check the operation


9. Each high-pressure after the end of the running machine


10. Measure the voltage, current, power, speed of more than ten units


11. Measure ground-resistance for each class I tool


12. Check the appearance of each machine (label on the machine, shell seam, burr, color aberration), noise, vibration, sparks, and practical functions.


13. Check the switch of each tool


14. Random sampling in according to AQL standards (S-3, CRI s 0, MAJ s 1.5, MIN s 4.0)


15. Measure the pull off strength of the power cord and the terminal leads,


16. Install/disassemble the product and check the consistency of internal key components against the CDF table (list of key components of certified product)


17. Check the internal structure, process, components, diameter, ground mark, wiring mode, leakage distance


18. Measure the distance from the winding to the core


19. Measure the size of the rotor and stater


20.Record capacitors with CDF


21. Measure the length of the plug and the wiring


22. Record the test results


23. Share findings with factory representative and ask them to sign on report.


Third, the use of power tools in the process of precautions


  (1) Know clearly the safety requirements of power tools

  Power tools are a good helper in our work, but safety is essential, before the formal use, must have a sense of safety on power tools, specifically need to understand the following points;


1. Performance of power tools

Have an understanding of relevant parameters of the power tool, such as its operating speed, voltage current strength, the operator's adaptability, the maximum load of the power tool, etc. , and in the course of operation can not arbitrarily change these parameters, increase the effective load of the power tool. Failure to do so will cause damage to power tools and damage to the human body.


2. Attention to the safety

Need to check if this power tool has safe protection measures, such as safe ground to prevent leakage, overheat protection device, and in the use of the process, if the load is too high and lead to heating and burning coil, the motor phase will change suddenly, increased to break through the protective shell and injured the operator.


3. Prevent the hazards from old and worn-out power tools

Old power tools generally use relatively poor insulation, coils are not in the optimal state, the wear of each bearing will also have errors, oil seals will also have a certain wear, resulting in a poor safety. Therefore, only after rigorous testing, to determine that the power tool is in good working performance, can continue to use.


4. The thorough alignment of production power tools should be scientific and reasonable

General vertical power tools need to have a special current matching equipment, strictly prohibit the private pull power cord. Sometimes even the power cord conductive are exposed, only a few laps wrapped by insulating adhesive, we do not know the power line insulation has aged corrosion or not,  but the reason for the accident in practice too much. It can be easily found in relevant news reports.

In the power tool line drawing, as far as possible to do one route after another control box, a control box only control a mechanical equipment, and have a person responsible for, personnel maintenance, timed detection. This is the first prerequisite for safe production.


(2) Further inspection is needed before use

The safety of the power tool, the normal operating performance, and the corresponding operating parameters are determined to meet the rated requirements. Do not force the use of resolutely, overload the use of equipment, determined to safety as the first production purpose.

 Only safe can make production be effective.


  (iii) Matters to be noted in the work:

  1. Careful use of these devices, for the relevant parameters of power tools to be in mind, not overload the use of equipment, in operation, carefully pay attention to the operation of power tools, have a high degree of vigilance for abnormal sound, once found abnormal, immediately cut off the power inspection.


  2. In the work, it is strictly forbidden for unrelated personnel to enter the operating area, to prevent flying iron chips and running by-products injury.


3. Do not bring gauze and yarn gloves to operate, so as not to be caught in the high-speed running equipment wrapped in gloves and hurt.


4.For grease-lubricated work-pieces, wearing eye protection and corresponding work-wear, female manipulators need to put long hair into the hat, never wear hair into the workshop.


5. Do not operate power tools alone, the site needs to be equipped with at least two people, to prevent the occurrence of unexpected accidents.


6. As far as possible the use of automatic adaptation to operation, if the mechanical equipment has such functions, you can try to use automatic adaptation of the operation, so that effective protection equipment does not overload the operation.


   (4) Maintenance after the use of power tools

   Maintenance power tool make the motion shaft in a lubrication state, observations on hydraulic needs, whether the hydraulic oil is sufficient, whether in a reasonable range, whether the oil seal leakage, power supply, whether the lamp is caused by good condition. etc.


   (v) Careful examination of power tools:

Every other shift, the electric tool needs to be tested for current to see if its operating current is in the normal range and whether the voltage exceeds or falls below the relevant parameters. Whether the components are in good condition. Among them, for the power tool power testing, needs to be conducted by professional people, it’s a certificated duty.