Power tool marking: protection and insulation classes. Power tools Portable power tools

Unless you work for a construction company where a competent person is involved in the selection of tools, most likely you need household equipment for the non-professionals. How to understand the classes of a power tool and understand if the power of the model you like will suffice? And vice versa - how not to overpay for those characteristics that you do not need? ..

We understand how power tools and hand-held electric machines are classified.

Power classification

This is not about how loudly the hammer drill knocks and whether an electric saw can be heard 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 or overheating. How important this is depends on the tasks that are set for the equipment and the conditions of its operation.

Industrial and Heavy Duty are portable power tool classes not found on store shelves. These are not just professional units that are used by masters from housing and communal services or masters "for an hour". They work without interruption for 16 hours, have reduced safety indicators, as they are intended for the work of professionals.
Heavy Duty has all the same characteristics and, in addition, increased dust and moisture protection and the ability to use accessories and accessories from other models. In other words, "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 it is known that less qualified operators use them. They can be allowed for use in harsh conditions, as well as expand their "specialization" - for this, the set often includes replaceable nozzles and other accessories. The target audience of this class is foremen working on call or in small production in one shift.
Hobby is a class of equipment that usually lays in a box for weeks and is removed for small household needs: repairs or handicraft items. It is allowed to operate with extreme 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 a high safety indicator for non-professionals.

Classification by purpose

The most familiar division of tools for us is according to the type of work that needs to be done.

And, finally, auxiliary tools belong to a separate class of tools: guns (glue, soldering and for tying fittings), 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 - by way 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 security class (this is described at the beginning of the article).

The classes of power tools and hand-held electrical machines can be identified by marking.

Class	Working insulation	Earthing	The purpose	Precautionary measures
0	There is	Not	Work in non-hazardous rooms	The tool must be installed in an instrument with a grounded housing
01	There is	Grounding device without grounding conductor	Work in non-hazardous rooms
1	There is	Earthing device with a conductor, plug "earth-contact"	Work in industrial premises and residential buildings	Connect to a grounded outlet. Working with rubber gloves
2	Double or reinforced	Not	Work in production facilities	No (except for use in wells and metal containers)
3	There is	Not	Any conditions, including in especially dangerous premises	Not

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

Heat resistance classification

The lower this class, the more often you will have to stop the device so that it cools down (20 minutes of operation after 15 minutes of break is the optimal value for power tools, with an increase in the class, the operating time also increases).

The very resistance to heat depends on the material of the winding.

Class	Winding materials	Maximum t
Y	Cellulose or silk	90 ⁰C
A	Cellulose or silk with dielectric treatment	105 ⁰C
E	Resin and organic film	120 ⁰C
B	Mica	130 ⁰C
F	Synthetic materials or asbestos	155 ⁰C
H	Elastomers and silicon-impregnated glass fibers	180 ⁰C
C	Mica, ceramics, glass, inorganic treated quartz	180 ⁰C

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

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

1st digit	Decryption	2nd digit	Decryption
0	No protection
1	Protection against bodies with a diameter> 5 cm	1	Protection against moisture falling on the device from above
2	Protected against bodies with a diameter> 2.5 cm (operator's fingers)	2	Protection against moisture falling on the device at an angle of 15 ⁰
3	Protected against bodies with a diameter of 2.5 mm (cables)	3	Protection against moisture falling on the device at an angle of 45 ⁰
4	Protected against bodies with a diameter> 0.1 cm	4	Complete protection against moisture
5	Full protection	5	Protection against moisture entering the device under pressure
6	Absolute protection (including dust)	6	Protection against moisture penetration in the event of a short drowning

The markings are intended to provide the user with an understanding of the hazard class of the power tool as much as possible. If you still have doubts, you need to consult with a specialist, be sure to indicate the qualifications of the operator for this tool, the conditions of use and the duration of work.

Check the requirements for your portable power tool before purchasing. They are regulated by state standards and technical specifications for electrical safety.

You can get acquainted with them, for example, on the Energocontact website.

First of all, let's list what belongs to a portable power tool. These are electric soldering irons, electric drills, screwdrivers, wrenches, furrow drivers, electric hammer drills, grinders, portable electric heating devices for technological needs, step-down transformers for powering power tools, local lighting fixtures, portable electrical panels and other current collectors.

Classes

Portable power tools are divided into classes.

The zero class includes a power tool with working insulation, without grounding elements, which does not belong to the second and third classes.

The first class power tool has working insulation and a grounding element. The wire to the power source must be equipped with a grounding conductor and a grounding plug.

The second class power tool has double or reinforced insulation, but there are no grounding elements.

The power tool of the third class is designed to operate at extra-low voltage (no more than 42 volts) and does not have any electrical circuits operating at a different voltage.

The voltage for instruments of the first and second classes is not more than 220 volts with direct current, 380 volts - with alternating current.

Premises

The voltage of the tool should not exceed 380/220 volts when working in rooms without increased danger and 36 volts in other rooms or outside them.

In premises with increased danger, there is one of the following factors: high dampness (relative humidity over 75%); temperature above 35 ° C; conductive floors; conductive dust; the possibility of simultaneous contact with the metal structures of the building, which are connected to the ground, or with technological equipment - on the one hand, and with the metal casing of electrical equipment - on the other.

Rooms with a relative humidity of about 100% are especially dangerous; with a chemically active or organic medium; containing two or more hazardous factors.

The main general requirement for individual users is to do mains work only if the power tool has a non-removable flexible cord with a plug. Protect the cord from damage and contact with damp, hot and oily surfaces.

When the plug is turned on, its design must ensure the early closure of the grounding contact, and when turned off, the subsequent opening. It also needs to be protected from moisture. The power tool must be quickly plugged in and unplugged (but not spontaneously).

Malfunctions

And the super main thing! If any, even minor malfunction is found, work must be stopped immediately!

Common problems with a portable power tool include: Damaged plug or cord. fuzzy operation of the switch; leakage of grease from the gearbox; sparking of the collector brushes with the appearance of a circular fire on the surface; the appearance of smoke, smell of burnt insulation, hanging noise, knocking or vibration.

It is very important for safe operation that the body of the power tool is zeroed.

Person

Power tools may only be operated by persons trained in the safe use of the power tool. In the event of a malfunction, you cannot independently repair the tool or its cord and plug - such repairs are usually not of high quality.

When working with a power tool, depending on their type, you need to use personal protective equipment, which include a cotton suit or dressing gown, dielectric gloves, galoshes, rubber and mats, etc. In especially dangerous premises, the use of personal protective equipment is mandatory!

Before starting work, it is necessary to carefully inspect the power tool for proper grounding and wire insulation, the absence of exposed live parts and defects. Do not use defective power tools!

Remember to unplug the power tool after finishing work.

There is a large assortment of power tools on the market, but not everyone knows how to make the right choice. Therefore, it is worthwhile to understand the classification and purpose of products before starting. Each requires its own equipment and tools. It is not so difficult to understand this issue. And today we will consider the types of power tools, purpose, application and features.

The main differences

There are several different classifications. The very first one is as intended.

To create holes, various recesses and make threads, there are: drills, screwdrivers, perforators, jackhammers and thread cutters. There are other options, but this list is the most common and often found on the market.
For wood finishing. These are planing, sawing, and milling. This includes a jigsaw, a plane, a variety of saws, milling cutters and a grinder. These are the main types of power tools that a person needs. If necessary, you can purchase something else.
To make the part flawless, it is ground and polished. This cannot always be done manually. So, there are files, and wall chasers. With them, the detail becomes flawless in a short period of time.
There are also such types of power tools, without which it is difficult to imagine any work. These are hair dryers, vacuum cleaner, soldering iron and other related equipment. They are classified as household appliances. These are available in every house or apartment.

There are various types of hand held power tools. These are the ones that can be carried and applied anywhere. They can be used depending on the need, which is very convenient. But there are those with the help of which you can do some work, but you will not be able to transfer it all the time.

It is clear that portable ones are capable of performing a wide variety of functions, but the advantage of a stationary one is the performance of complex and high-quality work. It's good to have both of these options at hand to get the job done.

Types of power tools by type of el. security

You can find the following classification:

0 - this includes tools in which all parts are energized, there are completely no components for grounding;
0I - also all parts with current, while there is grounding and working insulation;
I - power tools with the same component as the first two (the presence of insulation and grounding contact);
II - all parts are energized and well insulated, but there is no grounding;
III - voltage no more than 50 V, the power tool is powered from a safe low voltage.

Another subdivision method

Today, the entire tool is divided into classes. They make it easier to understand what to pick up and how to work. The main types of power tools for their intended purpose:

Industrial;
Heavy duty;
Professional;
Hobby.

Each of them has its own characteristics and characteristics. In addition, it is worth understanding how they work. Some are able to complete tasks for a long period of time, while others will need to be given a break or recharged. Before making a purchase, it is worth considering this. Otherwise, the service life may be reduced.

Industrial

This is the name of tools that work for a long time without breakage. Most often they are referred to as a conveyor process, so they do not turn off for 15-18 hours. Such units are distinguished by a long service life and reliability. In addition, repairs are often unnecessary. There is one peculiarity. Power tools of this type usually work in confined spaces, which means they must be completely environmentally friendly.

Ergonomics is another requirement for such installations. It will not work to call Industrial devices multifunctional, because they have limited capabilities. People with special education are allowed to them, so the level of security is low. Before starting work, it is worth creating certain conditions for operation:

the required voltage level in the network and maximum wiring reliability;
indoor humidity indicator;
temperature at which the device will not fail;
dust level.

Only in this way the tools will be able to fully work and perform the assigned tasks. If the conditions are not met, devices can quickly fail, although this is unusual for them.

Heavy duty

Translated from English, it means "heavily loaded". This includes such types of tools that can be compared with the first in their characteristics. While there is a significant difference, there is no need to create specific conditions. This is achieved by changing the design:

additional protection against moisture;
dust catching fence;
high level of impact resistance.

But the positive aspects do not end there either. You can use consumables and parts from simpler models during operation. They cannot be found on the shelves of simple stores, since this is a specialization of a narrow range. If necessary, they are made and delivered by special order.

Professional

This is the most popular type of professional tool. They are actively used in work. With their help, the most durable units and parts are created. The whole structure is highly reliable during operation. In addition, these devices have the following properties:

assembly precision;
high level of work and a long period of operation;
ease of maintenance;
adaptability to serious loads and adverse conditions.

The devices can operate non-stop for up to 9 hours. This is enough for one shift for workers. In terms of environmental indicators, this tool is inferior to the first two, but only slightly. But the ergonomics are lower, since the operating period is no more than 9 hours. Although there is a big plus - it is an increase in the level of safety during the period of work. This means that not only masters can work with them. In the event of a failure, finding a replacement part will be easier than for the first two types of power tools.

Hobby

Many people need just a household power tool. Hobby can be amateur, garden, garage. And it is not used often (from period to period). From this it is clear that he will not be able to work for a long time without stopping. When assembling, they do not use high-power motors, since a high efficiency factor is not required at the output. But the devices can run for up to five hours during the day. However, in the process, minor breaks are made so that the unit does not fail.

There are also significant disadvantages. Thus, much attention is paid to ergonomics, namely the protection of the user. But these types of tools are used by many, since no additional skill and experience is required. The entire arsenal of units should not be subjected to harsh operating conditions, because most often one person works with it. But the level of maintainability is low. Maintenance is not required (unless a personal inspection before starting work).

These are the main types of power tools, into which all the commercially available composition is subdivided. From this list, everyone understands what exactly he needs to acquire. There is another group worth knowing about though.

Universal devices

Today, you can find power tools on sale that have a wide variety of functions. In addition to their main purpose, they are able to do something in addition. This is not even one operation, but several. This includes a screwdriver, because it: tightens screws, makes holes, can act as a construction mixer, but subject to high power. The drill is another representative of such a group. His abilities are great - a hammer drill, screwing in screws, making holes. In such electrical equipment, you just need to change the nozzle and add or subtract power.

But giving preference to units that have many functions, do not forget about a minor minus. Additional work is not always performed efficiently. And it is not difficult to understand why this is happening. Any process implies its speed, power and duration. It can be seen from this that sometimes it is necessary to have highly specialized electrical installations in order to achieve the desired result and quality in work. Performing actions at the limit of its capabilities, the tool will simply fail or the consumable will break.

Conclusion

So, we examined the types of power tools and the area their application. The types can be very diverse. Also, the devices differ significantly in price. In such a situation, it is clear that in some works one cannot do without a highly specialized power tool. Not everyone needs such a unit all the time. In this case, you can rent the device for a time or rent. But work with him will turn out to be an order of magnitude better and faster. The main thing to know: choose the right type of power tool. The scope is what you need to pay attention to.

0 - electrical receivers with working insulation, without elements for grounding and not classified as class II or III

I- electrical receivers with working insulation and an element for grounding. The power cord must have a grounding conductor and a grounding plug. The designation at the grounding contact is PE or white-green stripes or the word "ground" in a circle

II- having double or reinforced insulation and not having elements for earthing. Designation - double square

III- electrical receivers for operation at safe extra-low voltage, having neither external nor internal electrical circuits operating at a different voltage. Designation - rhombus with III

Ultra-low (low) voltage- not exceeding 50 V AC or 120 V DC.

Workers with group II should be allowed to work with portable power tools and hand-held electric machines of classes 0 and I in rooms with increased danger.

Connecting auxiliary equipment (transformers, frequency converters, residual current devices) to the electrical network and disconnecting it from the network must be performed by electrical personnel with group III, operating this electrical network.

The class of portable power tools and hand-held electrical machines must correspond to the category of the room and the working conditions with the use of electrical protective equipment in some cases according to the requirements.

In rooms with increased danger and especially dangerous, portable electric lamps must have a voltage not higher than 50 V.

When working in particularly unfavorable conditions (switch wells, switchgear compartments, boiler drums, metal tanks), portable lamps must have a voltage of no more than 12 V.

Before starting work with hand-held electric machines, portable power tools and lamps, you should:

Determine the class of the machine or tool according to the passport;

Check the completeness and reliability of the fastening of the parts;

Make sure by external examination that the cable (cord), its protective tube and plug, the integrity of the insulating parts of the case, the handle and the covers of the brush holders, protective casings are intact;

Check the accuracy of the switch;

Perform (if necessary) testing of the residual current device (RCD);

Check the operation of the power tool or machine at idle speed;

Check the grounding circuit of a class I machine (machine body - grounding contact of the plug).

It is not allowed to use hand-held electric machines, portable power tools and lamps with related auxiliary equipment in work that have defects and have not passed periodic inspection (tests).

When using power tools, hand-held electric machines, portable lamps, their wires and cables should be suspended whenever possible.

Direct contact of wires and cables with hot, wet and oily surfaces or objects is not allowed.

The power tool cable must be protected from accidental mechanical damage and contact with hot, damp and oily surfaces.

It is not allowed to pull, twist and bend the cable, put a load on it, and also allow it to intersect with ropes, cables, gas-welding hoses.

If any malfunctions are found, work with hand-held electric machines, portable power tools and lamps should be stopped immediately.

Hand-held electric machines, portable power tools and lamps, auxiliary equipment issued and used in work must be accounted for in the organization (separate subdivision), be checked and tested within the terms and volumes established by technical regulations, national and interstate standards, technical specifications for products in force. the volume and standards of testing electrical equipment and electrical apparatus.

To maintain good condition, conduct periodic tests and inspections of hand-held electrical machines, portable power tools and lamps, auxiliary equipment, by order of the head of the organization, a responsible employee with group III must be appointed.

In the event of a power failure or interruption in work, the power tool and hand-held electric machines must be disconnected from the mains.

Employees using power tools and hand-held electric machines are prohibited from:

Hand over hand-held electric machines and power tools, at least for a short time, to other workers;

Disassemble hand-held electrical machines and power tools, make any repairs;

Hold on to the wire of an electric machine, power tool, touch rotating parts, or remove shavings, sawdust until the tool or machine comes to a complete stop;

Install the working part in the chuck of the tool, machine and remove it from the chuck, as well as adjust the tool without disconnecting it from the network;

work with ladders;

Introduce portable transformers and frequency converters inside the drums of boilers, metal tanks.

When using an isolation transformer, the following requirements must be observed:

Only one power supply is allowed from the isolation transformer;

Earthing of the secondary winding of the isolation transformer is not allowed;

The transformer case, depending on the neutral mode of the supply electrical network, must be grounded or neutralized. In this case, grounding of the housing of the electrical receiver connected to the isolation transformer is not required.

The frequency of checking portable and mobile electrical receivers, auxiliary equipment to them - at least once every 6 months. The results of the check are reflected in the register, inventory, periodic check and repair of portable mobile electrical receivers.

Periodic inspection includes:

1.external inspection

2.check idle operation for at least 5 minutes

3.measuring insulation resistance

10.1. Portable power tools and lamps, hand-held electrical machines, isolation transformers and other auxiliary equipment must meet the requirements of state standards and specifications in terms of electrical safety and be used in compliance with these Rules.

10.2. To work with portable power tools and hand-held electric machines of class I<*>in rooms with increased danger<**>Personnel with group II must be admitted.

<*>The classes of power tools and hand-held electric machines in terms of the method of protection against electric shock are regulated by the current state standards.

Connecting auxiliary equipment (transformers, frequency converters, protective - disconnecting devices, etc.) to the electrical network and disconnecting it from the network must be carried out by electrical personnel with group III, operating this electrical network.

10.3. The class of portable power tools and hand-held electrical machines must correspond to the category of the room and the conditions of work with the use of electrical protective equipment in some cases in accordance with the requirements given in table. 10.1.

10.4. In rooms with increased danger and especially dangerous, portable electric lamps must have a voltage not higher than 50 V.

When working in particularly unfavorable conditions (switch wells, switchgear compartments, boiler drums, metal tanks, etc.), portable lamps must have a voltage of no higher than 12 V.

10.5. Before starting work with hand-held electric machines, portable power tools and lamps, you should:

determine the class of the machine or tool according to the passport;

check the completeness and reliability of the fastening of the parts;

CONDITIONS OF USE IN OPERATION OF ELECTRIC TOOLS AND HAND ELECTRIC MACHINES OF VARIOUS CLASSES

Place of work	Class of power tools and hand-held electrical machines according to the type of protection against electric shock	The need to use electrical protective equipment
Premises without increased danger, premises with increased danger	I
	II
	III
Particularly dangerous premises	I	Not allowed to apply
	II	Without the use of electrical protective equipment
	III	Without the use of electrical protective equipment
Outdoors (outdoor work)	I	Not allowed to apply
	II	Without the use of electrical protective equipment
	III	Without the use of electrical protective equipment
In the presence of particularly unfavorable conditions (in vessels, apparatus and other metal containers with a limited ability to move and exit)	I	Not allowed to apply
	II	With the use of at least one of the electrical protective equipment (dielectric gloves, carpets, coasters, galoshes). Without the use of electrical protective equipment, if at the same time only one electrical receiver (machine or tool) receives power from an isolation transformer, an autonomous motor - a generator set, a frequency converter with separating windings or through a residual current device (RCD)
	III	Without the use of electrical protective equipment

check the operation of the power tool or machine at idle speed;

check on the class I machine that the grounding circuit is working (machine body - grounding contact of the plug).

It is not allowed to use hand-held electric machines, portable power tools and lamps with related auxiliary equipment that have defects in their work.

10.6. When using power tools, hand-held electric machines, portable lamps, their wires and cables should be suspended whenever possible.

Direct contact of wires and cables with hot, wet and oily surfaces or objects is not allowed.

The power tool cable must be protected from accidental mechanical damage and contact with hot, damp and oily surfaces.

It is not allowed to pull, twist and bend the cable, put a load on it, and also allow it to intersect with ropes, cables, gas-welding hoses.

If any malfunctions are found, work with hand-held electric machines, portable power tools and lamps should be stopped immediately.

10.7. Hand-held electric machines, portable power tools and lamps, auxiliary equipment issued and used in work must be checked and tested within the terms and volumes established by GOST, technical specifications for products, the current scope and standards for testing electrical equipment and electrical apparatus.

10.8. In the event of a power failure or interruption in work, the power tool and hand-held electric machines must be disconnected from the mains.

10.9. Workers using power tools and hand-held electric machines are not allowed to:

hand over hand-held electric machines and power tools, at least for a short time, to other workers;

disassemble hand-held electrical machines and power tools, make any repairs;

hold on to the wire of an electric machine, power tool, touch rotating parts, or remove shavings, sawdust until the tool or machine comes to a complete stop;

install the working part in the chuck of the tool, machine and remove it from the chuck, as well as adjust the tool without disconnecting it from the mains with a plug;

work with ladders; to perform work at a height, strong scaffolding or scaffolding must be arranged;

bring inside drums of boilers, metal tanks, etc. portable transformers and frequency converters.

10.10. When using an isolation transformer, observe the following:

from the isolation transformer, only one power supply is allowed;

grounding of the secondary winding of the isolation transformer is not allowed;