What applies to portable power tools. Power tools. Classification according to the degree of protection against penetration of foreign objects

General provisions.

1.1. The instructions were developed on the basis of DNAOP 0.00-8.03-93 "Procedure for the development and approval by the owner of regulations on labor protection in force at the enterprise", DNAOP 0.00-4.15-98 "Regulations on the development of instructions on labor protection", DNAOP 0.00-4.12-99 " Model regulations on training on labor protection issues", DNAOP 0.00-1.28-97 “Labor safety rules in road transport”, NAPB A.01.001-95 “Fire safety rules in Ukraine”.

1.2. The labor safety instructions for working with power tools establish safety requirements that must be observed when working with power tools.

1.5. The instructions are issued to everyone working with power tools upon signature. The employee must have the instructions with him at all times when working with power tools.

1.6. For violation of the requirements of the instructions, those responsible are liable in accordance with current legislation.

1.7. It is permissible to use only a tool that meets the requirements of regulatory documents for a specific type of tool.

1.8. The work must be performed only that which is assigned by the immediate supervisor, and it must be carried out with a serviceable tool, using it only for its intended purpose.

1.9. Drilling holes and punching grooves in the structures of buildings in which hidden electrical wiring, pipelines, etc. are located should only be done after removing the voltage from the corresponding electrical networks (blocking the corresponding pipelines).

This work must be carried out according to a work permit, which indicates the layout of hidden electrical wiring, pipelines, etc., as well as the necessary additional safety measures.

Mandatory requirements for personnel working with power tools.

2.1. Persons who have been trained in safe working methods, tested knowledge on labor protection issues, have received an appropriate certificate with a record of admission to work with power tools, have a qualification group in electrical safety, as well as practical skills in working with power tools are allowed to work with power tools.

2.2. In order to prevent vibration diseases, all workers involved in work with vibrating power tools must undergo a medical examination at least once a year.

2.3. Persons working with power tools must know:

Techniques for providing first aid to victims;

Standard (or developed at the enterprise) instructions on labor protection when working with power tools.

Classification of power tools and requirements for them.

3.1. A power tool includes a tool that is powered by an electric current source: an electric hammer, an electric chisel, an electric drill, an electric planer, an electric saw, an electric grinder, an electric soldering iron, etc.

3.2. The classification of power tools regarding safety precautions is given in Table 1.

3.3. Class II power tools are only available for voltages above 42 V and are marked.

3.4. The design of the plug of a class III tool must exclude the possibility of its coupling with a socket with a voltage higher than 42 V.

3.5. To connect the power tool to the power supply, only the cable (cord) included with the tool should be used.

If it is necessary to extend the power cable (cord), it is allowed to use a hose wire, for example, type ShRPL or ShPRS with a cross-section corresponding to the power of the tool. In the absence of such wires, it is permissible to use flexible wires (for example, PRG type) with insulation for a voltage of at least 500 V, enclosed in a rubber hose.

Table 1

Classification of power tools

3.6. Grounding of the power tool body must be carried out using a special wire for power supply, which must not simultaneously serve as a conductor of operating current. It is prohibited to use the neutral working wire for this purpose. In this regard, to power a three-phase power tool, a four-wire cable must be used, and for a single-phase power tool, a three-wire hose wire must be used.

The power hose wire for a Class 1 tool must have a plug at the end with the appropriate number of working contacts and one for grounding. The design of the plug must ensure that the grounding contact is turned on early and turned off after other contacts are turned off. If such plugs are not available, it is allowed to ground the tool with a bare flexible copper wire with a cross-section of at least 4 mm2, which must be connected to a special grounding bolt located on the body of the tool.

3.7. In cases where the power tool is powered by a step-down transformer, the body of the power tool must be grounded by connecting a grounding conductor to the grounding terminal of that transformer.

3.8. All power tools must be inventoried, have a serial number on the body and be recorded in a special journal in which periodic inspections are noted.

3.9. Power tools should be stored in a dry, heated room in cabinets or on racks.

3.10. For work, it is allowed to use a power tool that has been tested for a short to frame, broken ground wire or power wire, as well as an insulation resistance test (the test must be carried out with a 500 V megometer at least once every 6 months).

Repair of power tools should be carried out in specialized enterprises (divisions).

4. Rules for using power tools.

4.1. The possibility and rules for using power tools are determined by the category of the room in which the tool is used, according to the degree of danger of electric shock.

4.2. Determining the degree of danger of all production premises and classifying them into the categories indicated in the table is formalized by order of the enterprise.

4.3. The power tool should be used according to Table 2.

4.4. If it is impossible to provide workers performing work (except for construction and installation work) in premises with increased danger with tools of classes II and III, and in rooms with special danger and outdoors with tools of class III, it is allowed to use tools of classes I and II, provided that the tool (and only one) receives power from an autonomous motor-generator set, a disconnecting transformer or through a residual current device.

Work is carried out using personal protective equipment and grounding the tool body of class I.

table 2

Conditions for using power tools depending on the room category

4.5. When carrying out construction and installation work, it is allowed to use only power tools of classes II and III and only with personal protective equipment.

4.6. Outdoor work is only permitted with power tools that are protected from moisture (the tool is marked with a “drop in a triangle” or “two drops”). With tools that do not have this marking, working outside is permitted only in dry weather, and in rain and snow - under a canopy on dry ground or flooring.

5. Safety requirements before starting work

5.1. Before starting work you must:

Wear work clothes;

If necessary, prepare special vibration-proof mittens (soft mittens with double padding), safety glasses (glasses with unbreakable lenses), knee pads, elbow pads, ear muffs, safety belt;

Inspect the workplace, remove objects that interfere with work, and clear passages.

5.2. Depending on the nature of the work it is necessary:

Obtain a work permit when performing the work specified in clause 1.8;

Check the compliance of the tool class (according to the marking) with the nature of the work being performed;

Wear safety glasses and special vibration-proof gloves when working with impact tools;

Fasten sleeve cuffs and remove hanging ends of clothing when working with tools that have rotating parts;

Prepare and wear a safety belt when working at a height of more than 1.5 m;

Wear knee pads and elbow pads when working lying down;

Wear noise protection headphones when working inside any vessels involving technological operations with significant noise.

5.3. Make sure that there is sufficient lighting in the workplace and, if necessary, use a portable electric lamp, which should be equipped with a safety net with a reflector and a hook for hanging, checking that the lamp’s wire is in good condition. In high-risk areas, it is allowed to use portable electric lamps with a voltage of no more than 42 V, and in particularly dangerous areas and outdoors - no more than 12 V.

5.4. Check: the tightness of the screws securing the components and parts of the tool; condition of the wire, absence of external damage to its insulation and broken wires; serviceability of the switch and grounding; operation of the tool at idle speed. In this case, it is allowed to connect the power tool to the power supply only when the switch is in the “Off” position.

The following defects are not allowed:

Damage to the plug connection, power cable (cord) or its insulation;

Fuzzy operation of the switch;

Damage to the brush holder cover;

Cracks and other damage that reduce the strength of the body and handle;

Oil leakage from the gearbox or ventilation ducts.

5.5. The power cord of a power tool should be suspended if possible. If the wire is laid on the ground (floor), it should be protected from mechanical damage: close it, install fences, and hang warning posters.

Direct contact of the wire with metal, hot, wet and oily surfaces is not allowed.

5.6. When working with an electric drill, objects that are to be drilled must be securely secured.

6. Safety requirements during operation

6.1. The tool must be turned off immediately with the switch in case of a sudden stop (due to loss of supply voltage, jamming of moving parts, etc.).

6.2. The tool must be turned off from the power supply:

In case of a sudden stop due to the reasons specified in clause 6.1.;

During a break from work;

When moving a tool from one workplace to another;

During the employee’s absence from the workplace;

After finishing work or work shift;

When the instrument body is very hot;

When detecting a weak effect of electric current;

If the switch fails;

When installing, replacing or adjusting working tools.

6.3. If you detect a malfunction of the power tool, strong heating of its body or weak electric current after turning off the tool from the power supply, inform the work supervisor (immediate supervisor) about the need to replace the power tool and submit the faulty power tool for inspection (repair).

6.4. When cutting, riveting and other similar work in which metal particles may fly off, it is necessary to use safety glasses and install portable fencing panels so that people working or passing near the work site do not get injured.

6.5. When working with an electric drill, remove metal shavings with special hooks and brushes after stopping the drill.

6.6. When working with a heavy electric hammer, grinder and other tools weighing more than 10 kg, it is necessary to suspend them on a spring balancer or a special suspension.

6.7. Workpieces must be installed on work tables or other devices in an appropriate manner and in such a way as to prevent them from moving during operation.

7. Safety requirements after completion of work.

7.1. Turn off the tool with the switch, disconnect the power cord of the power tool from the power supply and remove the working tool from the power tool chuck.

7.2. If necessary, carry out maintenance of the power tool in accordance with the operating instructions.

7.3. Tidy up your workspace.

7.4. Place the power tool in a storage room or put it in a designated storage area.

8. When working with power tools, it is PROHIBITED:

Work in explosive areas;

Use for work a power tool that has the defects specified in clause 5.4.;

Ground the instrument body of classes II and III;

Exceed the duration of continuous operation specified in the instrument passport;

Transfer the power tool, even for a short time, to other persons who do not have the right to work with it;

Touch the cutting or rotating parts of the power tool;

Hold onto the power tool cord;

Remove shavings or sawdust by hand;

Work from ladders;

Treat frozen and wet wooden parts;

Pull and bend power cables of power tools;

Cross the power cables of power tools with other cables, ropes, electric welding wires and gas cutting hoses;

Use an autotransformer to power the power tool;

Cool the body of the power tool when it overheats with snow or water;

Continue working if: smoke or smell characteristic of burning insulation appears; all-round fire on the commutator due to increased sparking of the brushes; increased noise, knocking, vibration; damage to the working tool.

9. Actions in emergency situations.

9.1. When working with power tools, the following emergency situations are possible:

Short circuit in the power supply network of the power tool with possible further fire of the electrical wiring;

Damage to hidden electrical wiring with possible short circuit and fire;

Damage to hidden pipelines with possible release of hazardous liquids, vapors, gases;

Electric shock to an employee;

Employee exposure to hazardous liquids, vapors, gases;

Other emergency situations not directly related to the operation of a power tool.

9.2. Each employee who was the first to identify the threat of an emergency situation must immediately stop work and give the “STOP” command.

9.3. A STOP command given by any employee must be immediately executed by all employees who hear it.

9.4. The employee must immediately inform the work manager (immediate supervisor) about the threat or occurrence of an emergency situation.

9.5. If a short circuit occurs in the power supply network of the power tool or in another electrical network (electrical installation), immediately stop work and disconnect the damaged electrical network (electrical installation).

It is prohibited to repair a short circuit yourself.

9.6. If the electrical wiring (electrical installation) catches fire, immediately stop work, turn off the electrical network (electrical installation) and begin extinguishing the fire with a carbon dioxide fire extinguisher.

It is prohibited to extinguish fires in electrical installations with foam fire extinguishers.

A fire in the electrical network (electrical installation) must be reported to the fire department.

9.7. If hidden pipelines are damaged, stop work, shut off the damaged pipelines if possible and leave the danger zone.

9.8. If an employee is injured by an electric shock, release the victim from the effects of electric current: turn off the power supply: separate the victim from live parts using dielectric protective equipment or other insulating things and objects (dry clothes, dry stick, rubberized material, etc.); cut or cut the wire with any tool with an insulating handle.

9.9. If an employee is injured by dangerous liquids, vapors, or gases, remove (carry) the victim to a safe place.

9.10. In all cases, call a doctor to the victim, and before his arrival, provide first aid to the victim.

9.11. If there is a threat or occurrence of other emergency situations not directly related to the operation of a power tool, act in accordance with your responsibilities in accordance with the Emergency Response Plan.

(manager position

Divisions

/organization/developer)______________________________________________________________

AGREED:

Manager (specialist)

Security services

Labor of the enterprise ______________________________________________________________

(personal signature) (surname, initials)

Legal Advisor ______________________________________________________________

(personal signature) (surname, initials)

Chief technologist ______________________________________________________________

(personal signature) (surname, initials)

Unless you work in a construction company where a competent person selects tools, most likely you need household equipment for non-professionals. How to understand the classes of power tools and understand whether the model you like has enough power? And vice versa - how not to overpay for those characteristics that you do not need?..

Let's understand how power tools and hand-held electric machines are classified.

Power classification

This is not about how loud the hammer hammer is and whether you can hear an electric saw at the other end of the village. Power is the very characteristic that determines the ability of a tool to work for a long time, without stopping and overheating. How important this is depends on the tasks assigned to the equipment and the conditions of its operation.

• Industrial and Heavy Duty are classes of portable power tools that cannot be found on store shelves. These are not just professional units that are used by craftsmen from the housing and communal services sector or “hourly” craftsmen. They work without a break for 16 hours, have reduced safety indicators, as they are intended for the work of professionals.
• Heavy Duty have all the same characteristics and, in addition, increased dust and moisture protection and the ability to use equipment and components from other models. In other words, the “heavy artillery” among electrical equipment.
• Professional as a class is found on the shelves of specialized shopping centers. Their safety requirements are already higher, since they are known to be used by less qualified operators. They can be approved for use in harsh conditions, and also expand their “specialization” - for this purpose, the kit often includes replaceable nozzles and other components. The target audience of this class is craftsmen working on call or in small production on one shift.
• Hobby is a class of equipment that usually sits in a drawer for weeks and is taken out for small household needs: repairs or handicraft making items. It is allowed to operate only with care; it is not allowed to use it for more than half an hour: you should take a 15-minute break. A big plus is the high safety indicator for non-professionals.

Classification by purpose

The most common division of tools for us is based on the type of work that needs to be done.

• And finally, a separate class of tools includes auxiliary tools: guns (glue guns, soldering guns and for tying reinforcement), construction vacuum cleaners and hair dryers, dust collectors, spray guns, mixers for mixtures and solutions.

Classification by method of operation

Electrical safety classification

This classification - based on the method of protection against electric shock - and the following are the most serious. They are placed at the end of the article because to get to know them you need to understand, for example, why professional tools have a lower safety class (this is discussed at the beginning of the article).

The classes of power tools and hand-held electrical machines can be determined by markings.

The same classification of power tools for electrical safety is applicable to other household appliances: the first class of electrical safety is most common among equipment; the third is universal.

Classification by heat resistance

The lower this class, the more often you will have to stop the device to cool it down (20 minutes of operation after a 15-minute break is the optimal value for power tools; as the class increases, the operating time also increases).

The heat resistance itself depends on the winding material.

Classification according to the degree of protection against penetration of foreign objects

For convenience, IP-XX format marking is used, where the first digit in place of X indicates the degree of protection against solid particles, the second - against the penetration of moisture into the device.

The marking is intended to provide the user with the maximum understanding of the hazard class of the power tool. If doubts still remain, you need to consult with a specialist, making sure to indicate the operator’s qualifications for this tool, conditions of use and duration of work.

PTEEP and POT R M are written in blood... It sounds terrible, but that's how it is. Behind every line there are human victims. Neglect of safety rules leads to tragedy.

According to statistics, most often the victims of accidents in electrical installations are experienced electricians with extensive work experience and a high electrical safety group.

A person believes in his professionalism so much that he stops being afraid - and this is the sad result.

Any enterprise must deal with electrical safety issues specially trained person responsible for electrical equipment. This is not a position, but an “honorable duty,” as Rostechnadzor inspectors joke.

Let's quote PTEEP: "1.2.3. To directly fulfill the responsibilities for organizing the operation of electrical installations, the head of the Consumer (except for citizens who are owners of electrical installations with voltages above 1000 V) appoints with the appropriate document the person responsible for the electrical equipment of the organization (hereinafter referred to as the person responsible for the electrical equipment) ... The person responsible for the electrical equipment and his deputy are appointed from among the managers and specialists of the Consumer.” .

Exactly this specialist is assigned responsibilities on conducting special and organizing measurements and testing of power tools.

What is a portable power tool?

Electric impact wrenches, electric drills, electric planes, grinders and polishers and other electrified mechanisms not fixed to a permanent foundation, as well as electric extension cords and portable lamps - all this portable power tool.

Before entering into measurement and test results, it is necessary to carry out these actions. You need to start by assigning each power tool and portable light serial number(according to the new rules - inventory), which is written on the body with paint or a permanent marker in the place that is least exposed to mechanical stress.

Periodicity

Let’s look again at the “Rules for the technical operation of consumer electrical installations” and clause 3.5.11. we read that it is necessary to check portable power tools at least once every 6 months. Possibly more often.

Who has the right to carry out measurements and tests?

To carry out testing and measurement work special equipment required, instruments are an integral part of the electrical laboratory, therefore, the enterprise must have such a laboratory in order to carry out the work on its own.

If, due to various circumstances, an enterprise cannot afford such luxury, it should contact an organization that owns a licensed electrical laboratory and qualified personnel.

The electrical safety group for persons carrying out testing and measurement work must be not lower than III.

Logbook for recording and testing electrical equipment.

Posted information

Contains the following graphs:

• name of the power tool;
• inventory number;
• date of last test;
• reason for testing, inspection (after repair or periodic);
• insulation resistance measurement;
• checking the serviceability of the grounding circuit;
• external inspection and check of idle operation;
• date of the next test, inspection;
• the person who carried out the inspection, test (full name, signature).

We will consider the order of filling out each of the columns separately and in great detail.

Name

It must exactly match the name of the instrument indicated in the passport.

For example, you cannot simply write “drill”; you must indicate: “Makita HP 207 network impact drill.”

Inventory number

The procedure for assigning and applying an inventory number to the instrument body was discussed above.

At this stage, the inventory number is recorded without errors in the appropriate column.

Date of last test

Everything is very simple here: we write the date of the last test of a portable power tool, recorded. If the tool is new, enter the factory test date indicated in the passport in this column.

Reason for testing

There are only two such reasons: the instrument has been repaired and requires additional testing, or the next inspection is due (6 months have passed since the date of the previous test).

External inspection and checking idle speed

Checking a power tool should begin with an external inspection. Procedure:

• carefully inspect the body of the instrument, make sure there are no cracks, chips or dirt;
• carefully inspect the plug, paying attention to how tightly the pins are fastened in the body; if the plug body is dismountable, check the fastening screws, use a screwdriver to tighten all screw connections, and make sure the body is intact;
• Check the supply wire for flexibility, the absence of twists, breaks and cracks on the surface of the wire, inspect the attachment points to the plug and the body of the tool (double insulation must not be broken).

Checking idle speed carried out by connecting the tool to the electrical network and pressing the “Start” button. The power tool is tested without load. What to pay attention to:

Based on the results of inspection and testing at idle speed An entry is made in the journal, including the date of the inspection and its result.(satisfactory or unsatisfactory).

Insulation resistance measurement

This procedure is performed using a megohmmeter. Device requirements:

• output voltage – 1000 V;

The measurement is carried out by a team of two people, the electrical safety group of one of them should not be below III. Before starting work you need to check megohmmeter.

For this you need short-circuit the terminals of the device, rotate the handle until the arrow on the scale approaches 0. Then you need disconnect the leads and rotate the handle again. The instrument needle should deflect towards ∞.

Measurement procedure:

1. The terminals of the device are connected to the plug pins of the power tool being tested. It is necessary to pay attention to the terminal tips of the device did not touch each other. Depending on the type of megohmmeter, you need to rotate the handle of the device or press the button for 1 minute. Record the megohmmeter readings, stop measuring, disconnect the leads.
2. Fix one of the device terminals on the pin of the tool plug, the second - on a metal part of the tool body. Measure within 1 minute, record the instrument reading and stop measurement.
3. Connect the terminal of the device to another pin of the tool plug, Do not touch the device terminal previously connected to the metal part of the instrument body. Carry out the measurement for 1 minute, record the instrument reading, stop the measurement, disconnect the leads.

Insulation resistance considered normal, if the measured value exceeds 0.5 MΩ.

In the event that at least one of the measurements showed lower insulation resistance, the tested power tool is rejected (entry “Unsatisfactory” in the corresponding column of the journal).

If all three instrument insulation resistance measurements show satisfactory result, an entry is made in the appropriate column of the journal, recording the date of the test and its result (satisfactory).

Checking the serviceability of the grounding circuit

The test is performed on a power tool that has grounding pins on the plug. The purpose of this check is make sure the integrity of the grounding circuit, therefore, the closer the device reading is to 0, the better. Requirements for the device:

• the date of the next verification has not expired (indicated on the label attached to the device body, after the words “Best before...”);
• absence of dirt and visible mechanical damage (cracks, chips) on the device body.

The check can be carried out by one person. You should start with testing the performance of the ohmmeter: turn on the device and short-circuit the terminals. The arrow on the scale should point to 0. After opening the terminals, a working device will show ∞.

Actually circuit continuity check occurs as follows: one of the terminals of the device is attached to the grounding contact of the instrument plug, the second - to the metal parts of the case.

When the device is turned on, its readings are recorded, the result is entered in the appropriate column of the log with the date indicated.

Ground circuit is faulty, if the instrument readings tend to ∞ (record “Unsatisfactory”). In this case, the power tool cannot be used.

Date of next test, inspection

The frequency of inspections was mentioned above. It is worthwhile to dwell in more detail on those cases when tests are carried out more often than once every six months. This becomes necessary under the condition of active use of a portable power tool; the timing is determined by the person responsible for the electrical equipment.

How to determine the date of the next test: add 6 months to the current date(or the quantity determined by the person responsible for electrical equipment) and make an entry in the appropriate column of the journal.

The person who carried out the inspection or test

This column is entered details of the person who carried out the check(surname, initials) and his signature is placed.

This completes the filling out of the electrical tool inspection and testing log, so that in six months (or earlier) again repeat the whole procedure.

Some may think that all of the above measures are redundant, that there is absolutely no need to do them. Let's try to convince a hypothetical opponent of the opposite.

Rostekhnadzor statistics tell us that the majority of accidents (more than 60%) occur at consumer electrical installations. The reason is failure to comply with mandatory measures aimed at maintaining the safe condition of electrical equipment, including portable power tools.

It's worth thinking about unwillingness to follow rules leads to human casualties and draw appropriate conclusions.

• For drilling and installation use screwdrivers, drills, hammer drills, and jackhammers.
• For sawing- circular, chain, diamond, miter saws.
• For grinding and cutting- Angle grinders, grinders, engravers.
• For cleaning- construction vacuum cleaners, high pressure washers.
• For measurements- laser rangefinders and levels, metal detectors, etc.

• Power type: from mains or battery. With portable power tools you can work away from outlets: on the street, on the roof, on the road. Network ones are more suitable for long-term work.
• Class: household or professional power tool. The former will be useful for occasional home repairs. The latter are designed for intensive daily work.
• Equipment: Cases make storage and transportation easier, and additional batteries will extend operating time. Electrical tool sets are sold in online stores. Buying them is more profitable than buying devices separately.

Performing work using products that operate using current may pose a threat to the health and life of the worker. In order to make the use of electrical equipment safer, they came up with a classification. Having studied the classes of power tools, a worker can figure out what equipment he needs for a particular job. Cases of human being injured by electricity are not uncommon. Electrical safety classes of power tools contain information about what degree of protection a given product can provide to a worker.

What is subject to classification?

Power tool classes contain data on resistance to heat and the level of insulation in case of accidental human contact with live parts. In addition, the marking indicates the protection of the product from the ingress of water and foreign solid particles.

What information does an insulation class contain?

The use of any electric tool leads to heating of its engine. This, in turn, leads to the vulnerability of the material used as insulation and the safety of the worker himself.

Insulation class is an important parameter of electrical equipment, since it characterizes the quality of the motor winding and the degree of its heat resistance.

It indicates the temperature limit, exceeding which leads to engine combustion. The classes of power tools according to the insulation parameter are designated by Latin letters, each of which corresponds to a specific temperature regime.

Heat resistance

The division into classes of power tools based on heat resistance depends on the characteristics of the material used as the winding.

• Y: the lowest rates. Cellulose fibers, natural silk and cotton are used as windings. The heat resistance limit is 90 degrees C.
• A: cellulose fibers, silk and cotton treated with dielectric are used as wrapping material. The temperature limit is 105 degrees.
• E: organic film and resin (120 degrees) are used for winding.
• IN: organics are used - mica (130 degrees.)
• F: synthetics and asbestos are used (155 degrees.)
• H: is a silicone impregnation, elastomers and fiberglass (180 degrees.)
• WITH: highest class. The winding can withstand temperatures exceeding 180 degrees. A combination of mica, glass, quartz and ceramics is used. Inorganic is used as a binding material.

Classification according to the product’s resistance to heat also depends on the scope of application. According to their purpose, power tools can be either household or professional.

The difference between them is that the household appliance is not initially designed for long-term operation. It needs regular breaks to allow the engine to cool down. Every 20 minutes of work should alternate with 15 minutes of rest.

Classification by safety level

The division into classes of power tools and hand-held electrical machines is carried out depending on their level of safety:

• «0». This class is characterized by the presence of a rated voltage. There is no grounding. There is only working insulation. Designed for premises without increased danger.
• "01". There is working insulation and a grounding device in the absence of a grounding conductor to the power source.
• "1". A class 1 power tool contains working insulation, a grounding device, a core in the wire and a ground-contact plug. These are computers, washing machines, microwave ovens. The instruction manual states that when connecting the plug to a special socket containing a grounding contact, the use of such electrical equipment is not limited. In the absence of grounding, these devices are equivalent to class zero.
• "2". Does not contain grounding elements. Characteristic is double insulation of all parts with which contact is possible.
• "3". The power tool is powered at a voltage not exceeding 42 V and does not need to be grounded.

How to operate equipment depending on its class?

Each hazard class of a power tool dictates clear rules that must be strictly followed when operating the equipment. Thus, a tool of class “0” and “01” is allowed for use if it is mounted in a device with a grounded body. Class 1 power tools are suitable for industrial conditions (with the exception of particularly hazardous areas). To work with equipment of this class, it is necessary to use insulating materials such as a rubber mat and gloves.

For class 2, no additional precautions are provided, except when work is performed in wells and metal tanks. electrical products with safety class 3 are suitable for any conditions.

Marking

The hazard class of a power tool is marked with special symbols.

• 1st class indicated by three horizontal lines and one vertical line located at the top. All are circled.

• 2nd class is marked with two squares (one large square contains a smaller figure).

• 3rd grade has a marking depicting a rhombus, inside of which there are three vertical stripes.

Use of IP-xx markings

IP-xx marking is used to classify power tools according to the degree of their protection from penetration of foreign elements. It represents two numbers.

First digit

Indicates the degree of protection against solid foreign particles. Reflects both the level of risk of injury to the employee and the likelihood of breakdown of the mechanism of the electrical appliance itself.

• «0» – lack of any protection.

• "1"– the power tool is protected from particles whose diameter exceeds 5 cm. Equipment of this class is recommended for rooms without people.

• "2"– protected from bodies with a diameter of 12.5 mm (worker’s fingers). This is a plug socket and distribution panel.
• "3"– the product is protected from 2.5 mm bodies (tools or thick cable).
• "4"– equipment is isolated from bodies with a diameter greater than 0.1 cm.
• "5"– the tool is completely protected.
• "6"– absolute protection (even from dust).

Electrical equipment of the 5th and 6th classes are used in rooms with high levels of dust.

Second digit

Indicates the protection of electrical equipment from moisture.

• "1"– protection from drops that fall from above.
• "2"– protection against drops falling at an angle of 15 degrees.
• "3"– the protection angle is 45 degrees.
• "4"– comprehensive protection against water.
• "5"– comprehensive protection against water coming under pressure. Electrical equipment of class 5 can be used in open areas even during rain.
• "6"– the power tool is invulnerable to short-term flooding. The equipment is recommended for use on ships. It does not become unusable even in stormy weather.

The presence of the IP-xx marking indicates that electrical equipment components are reliably protected from exposure to moisture and mechanical elements.

Hand power tool classes

These power tools are equipped with a cord (the cable required for power). It is of the hose type and contains a protective tube that prevents bending of the wires, punctures of the insulation and any contact of the wires with the housing.

Depending on the method of protection against electric shock, there are three classes of electrical equipment intended for manual use:

• First grade. The cable is equipped with a neutral (grounding) conductor, which connects the housing and the protective contact located in the plug (for a plug connection). The tool is intended for industrial use only. Provides for the presence of at least one electrical insulating device (rubber gloves, rubber shoes or mat). Equipment of this class is prohibited for private use.
• Second class. The equipment is used in rooms with a high level of danger when wearing dielectric gloves.
• Third class. Electrical equipment is suitable for use in hazardous areas without the use of protective equipment.

Work with hand-held power tools is performed by workers who have qualifications of at least group two.

Safety precautions

When working with manual electrical equipment, it is very important to follow the safety rules:

• It is forbidden to work if, upon inspection of the tool, defects are found in it.
• It is advisable to suspend the power cables during operation.
• Care must be taken to ensure that the power cord does not come into contact with hot, damp, damp or oily objects or surfaces. Such contact can lead to mechanical damage to the cable and electric shock to the worker.
• Do not pull, bend or twist the cable. Also, do not place weights on it or confuse it with other cords.
• If any violations are detected, the operation of electrical appliances should be stopped immediately.

Portable power tool classes

1. «0» – equipment with working insulation without grounding devices.
2. "1"– a class of power tools with working insulation and a grounding element. The power cable is equipped with a grounding conductor and a corresponding plug, which contains the image of a circle with the inscription “earth”. It may also have PE markings or white and green stripes.
3. "2"– double insulation without grounding. Indicated by a double square.
4. "3"– power tools are designed for safety extra-low voltage. Marked with a diamond and three stripes.

Conclusion

Before you start using the power tool, you should check the operation of the power cable, plug, and insulating handle. To do this, experienced electricians recommend turning on the device and testing it idle. Such a launch will make it possible to detect defects by the characteristic sounds inherent in engine components with insecurely fastened parts. To check the ground continuity of class 1 instruments, you will need an ohmmeter.

You should also familiarize yourself with the class of the device, which is indicated in its passport. It is necessary to navigate the classification of electrical equipment to ensure safe operation. When operating electrical appliances, you must strictly follow the rules corresponding to each class.