Inspection and testing of hand-held power tools must be carried out at enterprises in accordance with labor protection rules.
However, if you often use a tool at home or in the country, checking the power tool periodically is extremely important to avoid possible problems.
Construction tools that are used intensively should be checked every 6 months. In general, you should accustom yourself to conduct a visual inspection of the tools for the current job before starting work.
What to check?
The most dangerous thing for a person when working with a power tool is the possibility of electric shock. To avoid this, check before each time you use a portable power tool:
- No damage to the plug;
- Integrity of the grounding circuit (this applies to instruments of electrical safety class 1);
- Cable integrity
- The presence and integrity of the protective tube located at the junction of the cable and the instrument body. The length of the tube must be at least 5 times longer than the thickness of the power cable.
Let's move on to the body of the power tool:
- Conduct a visual inspection of the entire area of the instrument, especially the joints: nothing should come off anywhere, no cracks or broken areas;
- All moving parts (for example, a chuck in a drill, hammer drill or screwdriver) must be securely fastened;
- The brush holder covers must be in good working order and free from mechanical damage;
- If there is a handle, it must also be securely fixed and intact;
- No grease leaks.
If the visual inspection of the power tool passes, you can turn it on and proceed to the next step.
- Check that the tool not only turns on and off, but the on and off button should not stick. If there is a safety button, it must also be in good working order;
- Listen to the sound of the instrument at idle speed. It should be uniform, moving parts should not “lobble”, also check for extraneous noise and vibrations of the housing.
Verification
Verification does not need to be carried out frequently; once every 10 days is sufficient for frequent use.
How often should I check?
Depends on the intensity of use of the tool, as well as working conditions. Under normal conditions it should be checked every 6 months. If operation occurs at low temperatures, frequent temperature changes, in rooms with high humidity, a lot of dust, or in an aggressive environment, the testing period for the power tool is reduced to 10 days. This is regulated by regulations for construction companies, but we also recommend that ordinary users adhere to these deadlines.
In general, the more often you check, the better. Regulations and documents establish the maximum inspection interval, but no one prohibits reducing it. This will only increase the safety and reliability of work. But under no circumstances neglect checks and do not increase the service interval, because this can lead to dire consequences.
Inspections at enterprises
Occupational safety standards provide clear regulations governing not only the inspection and testing of power tools, but also the procedure for recording, issuing and repairing power tools.
Each action with the tool is recorded in a special journal signed by the responsible employee. Each user must be familiar with safety precautions. Filled in according to the sample ( , ).
As a result of the inspection, if equipment defects are found, a special power tool inspection report or power tool test report is drawn up, which records all the necessary parameters and details. With this inspection report, the instrument is sent for repair. We attach a sample inspection report document: , .
An enterprise can have either one person responsible for accounting and storage of electrical equipment, or the second option, when each employee is assigned a tool that he constantly uses. Then responsibility, filling out documents and registering actions falls to him.
At the enterprise, it is simply necessary to monitor the implementation of all regulations on labor protection, because otherwise the supervisory authorities will cause quite a few problems, and in the event of an accident at work or injury, an application is immediately sent to the prosecutor's office with mandatory subsequent checks and tests of the power tool. If violations are detected, the responsible person will be punished, and penalties will be imposed on the company. It is important to keep all documents correctly completed and intact to confirm non-violation of established standards.
Checks at home
We don’t have supervisory authorities at home, in the country or in the garage, but this does not mean that we do not need to adhere to the rules for checking and testing power tools, because this is our personal safety.
Each power tool contains detailed instructions, which contain all the necessary information on the operation and testing of the tool. In addition, a visual check of the cable, housing and moving parts of any tool is required periodically at the beginning of work.
In addition, after using the tool, it must be cleaned of dirt, dust or shavings.
Often we use the tool very rarely. In this case, it is undesirable for it to just gather dust on the shelf. Try to take it out at least once every 3 months and “drive” it a little at idle speed.
We will leave the frequency of checks at the discretion of the owner of the instrument: the rule of intensity of use of the instrument is also used here:
- Frequent use, frequent checks;
- The more difficult the operating conditions (cold, temperature changes, aggressive environments), the more frequent the checks.
Based on this simple technique, you can choose the correct frequency of testing your power tool.
The benefits of tool checks
- Safety;
- Extending tool life;
- Prevention of tool breakdowns: sometimes a small “jamb” in the operation of the tool leads to failure of the entire device, and after that it is not always suitable for repair, or the cost of spare parts will make this repair unprofitable. So take a closer look and listen to your electrical assistants - vigilance will save you nerves, time and money.
Portable power tools must be periodically inspected at least once every six months.
Periodic inspection includes:
- visual inspection;
- check idle operation for at least 5 minutes;
- measuring the insulation resistance with a megohmmeter at a voltage of 500 V for 1 minute with the switch on, while the insulation resistance must be at least 1 MΩ;
- checking the serviceability of the grounding circuit (for class I power tools).
For a power tool, the resistance of the windings and current-carrying cable relative to the body and external metal parts is measured. The serviceability of the grounding circuit is checked using a device with a voltage of no more than 12 V, one contact of which is connected to the grounding contact of the plug, and the second to an accessible metal part of the power tool. The power tool is considered to be in good working order if the device indicates the presence of current. Testing the electrical strength of the insulation of a power tool must be carried out with an alternating current voltage with a frequency of 50 Hz: for a power tool of safety class I – 1000 V,
safety class II – 2500 V,
safety class III – 400 V.
The electrodes of the test setup are applied to one of the contacts of the plug and the metal body. The insulation of the power tool must withstand the specified voltage for 1 minute.
The results of inspections and tests of power tools must be entered into the “Register of inspection and testing of power tools and portable lamps.”
Power tools and auxiliary equipment should be stored in a dry room equipped with racks and shelves to ensure their safety.
Question 30. Requirements for work using portable electric lamps.
Portable hand-held electric lamps must have a reflector, a protective net, a hook for hanging and a hose cord with a plug. The mesh must be secured to the handle with screws or clamps. The socket must be built into the lamp body so that the current-carrying parts of the socket and lamp base are inaccessible to touch.
To power lamps in particularly hazardous areas and in areas with increased danger, a voltage of no higher than 12 and 42 V, respectively, should be used. It is prohibited to use autotransformers, choke coils and rheostats to reduce the supply voltage of electric lamps. To connect electric lamps to the network, should a flexible wire with copper conductors from 0.75 to 1.5 mm be used? with plastic or rubber insulation in a polyvinyl chloride or rubber sheath.
For luminaires in operation, the insulation should be measured periodically, at least once every 6 months, with a megger for a voltage of 1000 V; in this case, the insulation resistance must be at least 0.5 MOhm. Portable lamps must be stored in a dry place.
The electrical measuring laboratory of the Lab-Electro company will efficiently and quickly perform testing of personal protective equipment (PPE) and power tools. Tests are carried out using a specialized high-voltage stand by qualified employees of our laboratory, who have extensive experience and all the necessary approvals. At the end of the test, a stamp is placed on the product indicating the permissible voltage and the date of the next verification. Test reports are also drawn up and approved and issued to clients.
Is it necessary to test new dielectric gloves, boots, galoshes, tools???
We are often asked why test dielectric gloves, because it is easier and cheaper to buy new ones. But it's not that simple. There are rules that must be followed.
INSTRUCTIONS FOR USE AND TESTING OF PROTECTION MEANS USED IN ELECTRICAL INSTALLATIONS WITH 153-34.03.603-2003
1.4.4. Electrical protective equipment, except for insulating stands, dielectric carpets, portable grounding, protective fences, posters and safety signs, as well as safety belts and safety ropes received for operation from manufacturers or warehouses, must be tested according to operational test standards.
Our company’s stationary high-voltage electrical laboratory tests the following protective equipment:
- dielectric gloves;
- rubber dielectric boots and galoshes;
- hand insulating tool;
- insulating rods;
- insulating and electrical clamps;
- voltage indicators;
- insulating stands and caps;
- portable grounding.
After commissioning, PPE and power tools are subject to periodic and extraordinary testing. Extraordinary tests are carried out after repairs, replacement of components, or when a malfunction is detected. All testing of protective equipment made of dielectric rubber, power tools, rods, voltage indicators are carried out in accordance with the document “Rules for the use and testing of protective equipment used in electrical installations, technical requirements for them” and state standards. Before testing, an external inspection is carried out. If any defects are detected or the PPE is incomplete, it is considered faulty and testing is stopped. If the external examination gives a positive result, the product undergoes testing, including control of mechanical and electrical characteristics.
Work algorithm
1. Send an application to our email address info@site with a list of PPE being tested and your details.
2. Within an hour you receive an invoice and a test agreement in response.
3. Bring PPE to the test. You receive original documents:
- contract - 2 copies,
- check,
- certificate of completion of work - 2 copies,
- act of acceptance and transfer of personal protective equipment.
4. After 7 days, you pick up the tested PPE with a set of documents:
- test report,
- electrical laboratory certificate,
- invoice.
PPE is issued only after the money has been received in our bank account and the following documents have been provided on your part:
- signed contract,
- signed certificate of completed work,
- power of attorney to receive personal protective equipment.
The main electrical protective agent when working in electrical installations up to 1000 V and additional in electrical installations over 1000 V are dielectric gloves. It is acceptable to use gloves made of natural rubber and sheet rubber no shorter than 350 mm. Frequency of testing dielectric gloves established in the "Rules" and constitutes once every 6 months. Dielectric gloves undergo only electrical tests, during which the magnitude of the current passing through them (no more than 6 mA) and the absence of breakdown are determined. The testing period for dielectric gloves does not change even if the product has not been in use.
Dielectric boots and overshoes protect against step voltage and are classified as additional personal protective equipment, overshoes for installations up to 1000 V, and overshoes for installations up to and above 1000 V. Externally, overshoes and overshoes should look like this: rubber top, rubber corrugated sole, textile lining. Boots must be no shorter than 160 mm and have cuffs. Testing dielectric bot occurs by applying a voltage of 15 kV, and testing dielectric galoshes applying a voltage of 3.5 kV for 1 minute. If the flowing current does not exceed 2 mA for galoshes, and 7.5 mA for boots, the products are considered to have passed the test.
Testing hand-held power tools (side cutters, screwdrivers, pliers, pliers)
Power tools, such as pliers, screwdrivers, pliers, wire cutters, are used as the main electrical protective equipment when working on electrical installations up to 1000 V. Requirements for the appearance and quality of insulation of power tools are described in the “Rules”; if they do not meet them, the products are considered unsuitable. In operation only electrical tests of insulation of hand tool handles. Tests of power tools with single-layer insulation are carried out by applying a voltage of 2 kV for 1 minute. Testing tools with insulating handles with double or triple insulation are carried out with the integrity of all coatings.
Operational insulating rods are used to perform various operations on live overhead communication lines. The main parts of the rod are the working and insulating parts, the handle. Structural and technical requirements for operational insulating rods are contained in GOST 20494-90. Operating rod testing, used when operating up to 1000 V, is produced by simultaneously applying a voltage of 2000 V to the working part and to a temporary electrode applied to the insulating part for 5 minutes. , used on communication lines up to 35 kV, is produced by applying an alternating current voltage with a frequency of 50 Hz, equal to three times the linear one. For rods with a voltage of 110 kV and above - equal to three times the phase voltage.
The absence or presence of voltage in electrical installations up to and above 1000 V can be determined using voltage indicators. The dimensions of voltage indicators must be such that when working with them, the possibility of a ground fault or short circuit is excluded. GOST 20493-90 contains requirements for voltage indicators for alternating and direct current with voltages up to 1000 V and alternating current with voltages above 1000 V. Voltage indicator tests carried out by applying increased voltage to the working and insulating parts. The working part of voltage indicators intended for work from 35 to 220 kV is not tested. The magnitude of the test voltage is determined by the operating voltage of the pointer and is given in the “Rules”.
Portable power tools include devices used for construction or repair that are powered by an electrical outlet. Belonging to the “portable” category determines that they are delivered to the place of work without the use of mobile mechanisms and lifting devices. They are used personally by one or two people.
Portable tools and accessories include:
- tools with an electric motor - electric drills, hammer drills;
- portable lamps;
- electrical extension cords;
- transformers and converters for powering tools and portable lamps operating on reduced voltage;
- pneumatic and hydraulic tools;
- hand tools powered by internal combustion engines;
- hand pyrotechnic tools.
We will focus only on figurative power tools.
How accounting and testing of power tools are organized in organizations
Working with power tools can cause injury. A worker suffers an electrical injury when an electrical part malfunctions. When working in fire or explosion hazardous areas, a fire or explosion occurs. When using a power tool, the protection class and the requirements of labor protection rules are taken into account, which determine the procedure for using devices of the corresponding class in premises, depending on their danger. Protection classes are marked with numbers 0, I, II or III.
Workers are injured not only due to faulty electrical parts of the tool, but also due to faulty mechanics.
The second risk factor is injuries associated with damage to the mechanical part of the instrument.
If an employee is injured, the fact of the accident is recorded, an investigation is conducted, and a report is drawn up. If the injury occurs while using a power tool, proof that the tool is in working order will be required. PTEEP and labor protection rules require that the tool has undergone periodic testing according to established order. The test results are recorded in a log. This way you can document that his condition was monitored. If, as a result of the investigation, it turns out that the log or systematic entries in it are missing, the employer automatically becomes to blame for the employee’s injury.
In addition to testing, at the enterprise or in the department Instructions for the safe use of power tools are being developed. Workers using such a tool are introduced to it under signature. If an injury occurs as a result of a violation of such instructions, the blame automatically shifts to the injured worker. If there are no instructions, or the employee is not familiar with them, the employer will be solely responsible for the employee’s injuries.
But let's get back to the tests. Appointed at the enterprise employee responsible for the proper condition of power tools. He is selected from electrical (electrical repair) personnel and must have electrical safety group III or higher. If an enterprise consists of several divisions and there are difficulties with centralized checking of power tools, such workers are appointed in each workshop.
Appointment of a responsible employee justified by an order for the enterprise signed by its leader.
The responsibilities of the employee responsible for the safe operation of portable power tools include: maintaining a log book and organizing inspections and tests.
Portable power tool logbook
The need to collect information about the availability of a tool is dictated by the fact that not a single copy of it will be missed by the test procedure. Otherwise, so that not a single unit is forgotten. For this Each tool is assigned an inventory number, applied to the body of the instrument with indelible paint.
The cover of the magazine and the composition of its columns are presented below.
It is advisable to allocate one journal page for each instrument. This makes it more convenient to trace the history of its inspections and test results.
At the end of each line in which the test results are recorded, the person responsible for the safe operation of the power tool puts his signature.
How an electrified tool is tested
Periodic inspections and tests of power tools are carried out at least once every 6 months. If the tool is used intensively at an enterprise or department, then this period is reduced. The new test period is fixed by issuing a corresponding order for the enterprise.
After repairing the tool, an additional (extraordinary) inspection and test is carried out.
The test results are recorded in a log. The scope of the check is as follows:
- visual inspection;
- operating the tool at idle speed for at least 5 minutes;
- insulation resistance measurement;
- checking the grounding circuit.
Before inspection, the instrument body is cleaned of contaminants that impede an objective assessment of its condition. The first step is to check whether there is an inventory number on the case and that the characteristics of the instrument correspond to the information in the magazine.
Then the state of the electrical plug for connection to the network is determined. The absence of cracks, chips is checked, the contacts should not be deformed or burnt. A faulty plug must be replaced.
Next to the plug, inspect the power cord. Throughout its entire length, the insulation must not be broken. It should not be overtightened or twisted, and there should be no areas with increased or decreased flexibility. The point where the cord enters the power tool must be protected from bending by a properly functioning standard protection.
The operation of the power switch is checked without being connected to the network, its operation without the use of increased pressing force. The latch (if present) must firmly hold the power key pressed. Removal from the latch is carried out without delays or jamming.
If there are rotating parts, check their rotation by hand. At the same time, extraneous sounds and the absence of axial play are assessed. The jaws of electric drill chucks must not be worn or damaged. You should also try installing a drill in a drill, a disc in an angle grinder, or changing them. At the same time, the operation of fastening and locking devices is checked.
The integrity of the body of the power tool is checked, the absence of cracks and chips, the presence of shields, casings, limiters and other protective equipment provided for by the design.
Idle check
During the inspection, possible damage, wear of the mechanical part or malfunctions of the electrical part of the tool are identified.
Pay attention to:
- the appearance of a smell of burnt insulation or overheated lubricant;
- sparks or smoke from the brush apparatus or windings;
- sounds characteristic of bearing wear;
- case heating.
Insulation resistance test
The measurement is carried out with a special measuring device - a megohmmeter, for a voltage of 500 V. The duration of application of the test voltage from the megohmmeter is 1 minute.
Before using the device, make sure it is in working order. To do this, they perform two control measurements:
Insulation resistance measurements are performed while the “On” button of the power tool is pressed. The test voltage is applied between the product body and any power conductor. The measured value should not be lower than 0.5 MΩ.
To test extension cords, three measurements are taken by connecting the megohmmeter probes between:
- zero and phase conductors;
- zero and grounding conductor;
- phase and grounding conductor.
For a step-down transformer, the insulation resistance of the primary and secondary windings relative to the housing and to each other is measured.
Testing voltage converters with a megohmmeter is carried out according to the manufacturer's instructions, since they contain semiconductor devices.
Checking the ground circuit
Testing is only required for tools with protection class I and a plug with a grounding pin. Through it, the device body is connected to the PE bus of the power supply network. The measurement is made between the housing and the grounding pin of the plug. The result should not exceed 0.5 Ohm.
For measurements, special ohmmeters are used that not only measure resistance, but also supply some current to the circuit under test.
Megaohmmeters and ohmmeters undergo metrological verification in a timely manner, and measurements are carried out by a certified electrical laboratory.