Tire color code. Color marking of wires How tires are designated for three-phase alternating current

Today, all wires used for laying electrical networks and connecting electrical equipment are painted in special colors. This greatly simplifies the maintenance and replacement of wires, as well as identifying the causes of problems and breakdowns.

In the first picture below, we presented the most popular color markings of wires. These color solutions may not solve all problems, so be sure to read the entire article.

Why do you need color coding?

Color coding of wires in electrical engineering is a necessity because it makes wiring and reading electrical diagrams much easier. If we consider as an example the connection diagram of a simple light switch, it may seem that marking is not necessary, since everything is simple and clear.

However, if we take as an example a circuit diagram for connecting a distribution panel with a large number of differential circuit breakers and protective devices to the network, we will immediately notice the difference.

If it were not for the identification of wires by color, it would be very difficult to figure out which device or cable is faulty and in which circuit they are connected.

In addition, when the wires are painted a certain color, their installation is greatly simplified, since the likelihood of making a mistake and mixing up the wires is reduced. If, for example, we confuse phase and zero when connecting devices to the electrical panel in our apartment, this can lead to a short circuit, equipment breakdown, or, even worse, electric shock.

Manufacturers paint cable wires in certain colors not in a random order, but according to the rules of electrical installations. They describe exactly what markings can be used on wires under certain conditions. In addition, the 7th edition of the PES (from 2002) prescribes the identification of cables and wires according not only to their color, but also to their symbols.

Today, Russia has adopted a unified standard for the color identification of wires, according to which all electrical work with conductors must be carried out. According to these requirements, each core of wires or cables must have a separate color. The most commonly used are blue, green, brown and gray, however, if necessary, additional colors and shades are used. It is recommended to make the markings visible along the entire length of the conductor, but you can also use wires in which only the edge of the core is colored. To identify such conductors, colored heat-shrinkable tubes or insulating tape of the desired color are installed at the connection points.

Below we describe what markings are used for individual types of wires depending on the type of network and equipment.

Colors of wires in a three-phase AC network

In three-phase power networks, when connecting transformer equipment, substations and similar electrical installations, the phase busbars are painted in a certain color according to the following rule:

• phase A – yellow;
• phase B – green;
• phase C – red.

In DC networks

Despite the fact that in most cases we deal with alternating current, DC power networks also have a wide range of applications:

• In the industrial and construction fields - for the operation of electric cranes, trolleys and warehouse loading equipment.
• For powering electric transport: trolleybuses, trams, electric locomotives, motor ships, etc.).
• To supply load to operational protective circuits and automatic equipment of electrical substations.

As we know, a DC cable consists of two wires, for which concepts such as neutral and phase conductors are not used. The cable design includes only two buses with opposite charges, which are sometimes simply called “plus” and “minus”.

The accepted marking of wires requires that the positive pole in such a network be marked in red, and the negative pole in blue. The neutral contact, designated M in the diagrams, is colored blue.

When a two-wire network is connected to a three-wire network, it is necessary that the colors of its wires or tires exactly match the color of the power supply contacts to which they are connected.

Color marking of phase, neutral and ground

For wiring and installation of electrical networks in domestic and industrial facilities, multi-core cables are used, each wire inside of which is painted in a distinctive color. This is necessary, as already mentioned, to simplify the installation and maintenance of the network.

So, for example, if a network repair is carried out by a person who was not involved in its installation, he will immediately understand the working diagram by the color of the wire connected to devices and power supplies. Otherwise, it will be necessary to punch through zero and phase manually using a probe. This process is not easy even when checking new wires, and if it is necessary to repair old wiring, it will completely turn into a test, since earlier, in Soviet times, wires were not marked, and they were all covered with a black or white insulating sheath.

According to developed standards (GOST R 50462) and electrical installation rules, each wire in the cable, be it zero, phase or ground, must have its own color, which indicates its purpose. One of the main requirements of electrical installations is the ability to quickly and accurately determine the function of a wire in any section. Color marking is best suited to solve this problem.

The wire markings presented below are designed for AC networks and electrical installations (transformers, substations, etc.) with a solidly grounded neutral and a rated voltage of no more than 1 kV. Most residential and administrative buildings meet these conditions.

Protective and working neutral conductor

Zero or neutral on electrical diagrams is indicated by the letter N and is painted throughout in light blue or dark blue without additional color designations.

PE – protective zero contact or simply “ground”, has a characteristic color of green and yellow lines alternating along the wire. Some manufacturers paint it a uniform yellow-green shade along its entire length, but GOST R 50462-2009, adopted in 2011, prohibits the designation of grounding by yellow or green separately. In combination green/yellow, these colors can only be used in situations where they indicate grounding.

PEN wires used in today's outdated TN-C systems, where ground and zero are combined, have more complex markings. According to the latest approved standards, the main part of the wire throughout its entire length should be painted blue, and the ends and junctions should be painted with yellow-green stripes. It is also possible to use wires with opposite markings - a yellow-green wire with blue ends. It is rare to see such a wire in modern buildings, since the use of TN-C was abandoned due to the risk of electric shock to people.

To summarize the above:

1. zero (zero working contact) (N) – blue or light blue wire;
2. earth (zero grounding) (PE) – yellow-green;
3. combined wire (PEN) – yellow-green with blue marks at the ends.

Phase wires

The cable design may contain several current-carrying phase wires. Electrical codes require that each phase be identified separately, so the colors used are black, red, grey, white, brown, orange, purple, pink and turquoise.

When installing a single-phase circuit connected to a three-phase electrical network, it is necessary that the color of the branch phase exactly matches the color of the phase contact of the supply network to which it is connected.

In addition, the standard requires that all wires used be unique in color, so a phase cannot have the same color as neutral or ground. For cables without color identification, markings must be applied manually - with colored insulating tape or casings.

In order not to be faced with the need to purchase heat-shrinkable tubing or electrical tape during installation (and not to complicate the diagrams with unnecessary symbols), you should decide what combination of colors will be used in all electrical circuits of the house, and purchase the required number of cables of each color before starting work.

Applying markings to the laid cable

Electricians often have to deal with a situation where it is necessary to repair an electrical panel or network, but the equipment is connected in such a way that it is not clear where the phase and neutral are located, and where the ground is. This happens when the installation of the system is carried out by an inexperienced person, without special knowledge, for whom not only the markings, but also the location of the cables inside the switchboard are incorrect.

Another reason for such problems is the outdated and irrelevant qualifications of electricians. The work is done correctly, but in accordance with the old standards, so for the specialist who comes as a “replacement”, it becomes necessary to “punch” with a tool where the zero is located and where the phase is.

There is no point in arguing about who is to blame and whether anyone should do the repairs themselves; it is better to decide how to apply the correct and understandable markings.

So, current standards establish that color markings on electrical conductors cannot necessarily be placed along their entire length. It is allowed to mark it only at the points of connection and connection of contacts. Therefore, if you need to mark cables without markings, you should buy a set of heat-shrinkable tubes or insulating tape. The number of colors depends on the specific circuit, but it is advisable to purchase a standard “palette”: zero - blue, ground - yellow, and phases - red, black and green. In a single-phase network, naturally, the phase is indicated by one color, most often red.

The use of colored electrical tape or heat-shrinkable casings is also suitable for situations where the existing wire does not meet the requirements of the PEU. For example, if you need to connect a four-core cable to a three-phase network with wires of white, red, blue and yellow-green. These wires can be connected in any order, but be sure to place cambrics or windings of electrical tape with the “correct” colors at the connection points.

In addition, you should remember the problematic situations described above when installing a new unit or connecting equipment. The lack of clear and understandable symbols can significantly complicate further maintenance of the circuit, even for the person who installed it.

If you find that your distribution panel or network uses wire symbols that do not meet current requirements, do not rush to replace them. Before repair or dismantling, the wiring is subject to the standards that were in force at the time of its installation. Additionally, if the network is functioning properly, replacement is not required. And when commissioning a new (or converted old) electrical network, you will have to take into account and comply with all modern requirements and rules.

Question
What color designation is installed for single-phase AC buses?

Correct answer
The alphanumeric and color designations of tires of the same name in each electrical installation must be the same. Tires must be marked:

1) with three-phase alternating current: buses of phase A - yellow, phase B - green, phase C - red,

2) with single-phase alternating current, bus B, connected to the end of the power source winding, is in red, bus A, connected to the beginning of the power source winding, is blue (since it is considered the zero operating bus).

Single-phase current buses, if they are a branch from the buses of a three-phase system, are designated as the corresponding three-phase current buses;

3) at constant current: positive bus (+) - in red, negative (-) - in blue and zero operating M - in blue. The color coding must be carried out along the entire length of the tires if it is also provided for more intensive cooling or anti-corrosion protection.

It is allowed to carry out a color designation not along the entire length of the busbars, only a color or only an alphanumeric designation, or a color in combination with an alphanumeric designation at the points where the busbars are connected. If non-insulated busbars are not accessible for inspection during the period when they are energized, then they may not be marked. At the same time, the level of safety and visibility when servicing the electrical installation should not be reduced. (1.1.30 PUE)

Chapter 1.1 of the PUE, 7th edition, effective from January 1, 2003, establishes the following requirements for the identification of conductors (highlighted to us):
"1.1.29. For color and digital designation of individual insulated or non-insulated conductors, colors and numbers must be used in accordance with GOST R 50462 “Identification of conductors by colors or digital designations”.
Protective grounding conductors in all electrical installations, as well as zero protective conductors V electrical installations with voltage up to 1 kV with a solidly grounded neutral, including tires, must have the letter designation PE and a color designation with alternating longitudinal or transverse stripes of the same width (for tires from 15 to 100 mm) of yellow and green colors.
Zero workers(neutral) conductors are designated by the letter N and blue. Combined neutral protective and neutral working conductors must have the letter PEN and color designation: blue along the entire length and yellow-green stripes at the ends.
1.1.30. The alphanumeric and color designations of tires of the same name in each electrical installation must be the same.
Tires must be marked:
1) at alternating three-phase current: tires phase A – yellow, phase B – green, phase C – red,
2) when alternating single-phase current bus B, connected to the end of the power source winding, – in red, bus A, connected to the beginning of the power source winding, – yellow.
Tires single-phase current, if they are a branch from the buses of a three-phase system, they are designated as corresponding buses three-phase current;
3) at constant current: positive bus (+) – in red, negative (–) – blue And zero working M – blue. …».

The quoted requirements contain numerous errors. Firstly, the requirement of clause 1.1.30, which prescribes the use of yellow and green to identify two phase buses, should be considered a gross mistake. GOST R 50462–92, which was in force from January 1, 1994 to December 31, 2010, prohibited the use of yellow and green separately if confusion with the yellow-green color was possible. GOST R 50462–2009, which replaced it, which is valid until September 30, 2016, prohibited the use of yellow and green colors separately for identifying conductors. A similar ban is contained in the new GOST 33542 (see).
The use of yellow and green colors to identify phase busbars creates conditions in low-voltage electrical installations under which it is possible to confuse protective busbars with yellow-green markings and phase busbars with yellow or green colors. At the same time, the probability of erroneous connection of protective conductors of electrical wiring to phase buses increases and, as a result, the appearance of voltage on open conductive parts of class I electrical equipment, touching which becomes fatal to humans.
Secondly, busbars, which are one of the options for conducting conductors, are usually used in low-voltage switchgear, which are manufactured and certified in accordance with the requirements of national standards, which establish that the color identification of conductors must comply with the requirements of GOST R 50462–92 or GOST R 50462–2009.
Thirdly, the simultaneous use of blue and cyan colors to identify the pole and middle buses will inevitably lead to dangerous confusion, since the pole bus can be under a voltage of 110, 220, 440 V or more, and the middle bus is under a voltage almost equal to zero. Moreover, GOST R 50462–92 considered blue and light blue as one color.
Fourthly, the cited requirements use the concepts “ single phase current" And " three-phase current", which is a blunder. Electrical systems, electrical networks, electrical installations, electrical circuits and electrical equipment can be single-phase or three-phase. Electric current according to GOST R 52002–2003 “Electrical engineering. Terms and definitions of basic concepts" can be variable, constant, pulsating and sinusoidal.
Fifthly, in the considered requirements formulated for DC electrical circuits, it is mentioned zero operating bus. However, neutral conductors, including busbars, are used in AC electrical circuits. In DC electrical circuits, middle conductors are used. Therefore, the specified bus must be named middle tire.
Sixthly, phase conductors in the requirements are designated by the letters “ A, B, C" However, in IEC standards and national standards developed on their basis, phase conductors are designated differently - “ L1, L2, L3».
Seventh, the analyzed requirements are formulated for electrical installations with voltage up to 1 kV, and IEC standards and corresponding national standards establish requirements for low voltage electrical installations, operating at voltages up to 1000 V AC and up to 1500 V DC inclusive.
Eighth, the requirements use outdated terminology that does not correspond to the terminology of GOST 30331.1 (see).
The occurrence of errors in the requirements for color and alphanumeric identification of conductors is explained by the following reasons. Requirements of clause 1.1.29 PUE 7th ed. were formulated on the basis of the requirements of GOST R 50462–92, and the requirements of clause 1.1.30 of the PUE 7th ed. were rewritten from clause 1.1.29 of the PUE 6th ed. sample 1985. Thus, the generally accepted principles of color identification of conductors, established by the International Electrotechnical Commission and contained in the requirements of GOST R 50462–92, GOST R 50462–2009 and other national standards developed on the basis of IEC standards, have not yet received their correct reflected in the requirements of the PUE. Although the 23 years that have passed since the entry into force of GOST R 50462–92 and the GOST R 50462–2009 that replaced it were more than enough to adjust all national regulatory documentation and, moreover, the correct formulation of the analyzed requirements in Chapter 1.1 of the 7th PUE ed.

Conclusion. The requirements set out in clauses 1.1.29 and 1.1.30 of the PUE 7th edition must be replaced with the following:
Color and alphanumeric identification of conductors in electrical installations should be performed in accordance with the requirements of GOST 33542–2015 .

Electrical busbars are necessary to connect individual elements of electrical installations into a single whole.

Definition

Busbars allow you to combine all elements of an electrical installation into one whole. Essentially, these are conductors whose resistance is low.

When several busbars are combined at one point, they speak of busbar trunking. As a rule, they are installed on insulators, which also serve as supports. It is hidden in a special box (channel). Thanks to this, it is protected from environmental factors. The busbar must always be resistant to dynamic and thermal loads and shock current from the electrical network.

Electric buses are made in several designs. To divide them into types, several classifications are provided.

According to the method of execution, flexible and rigid tires are distinguished. They are also called flat and tubular. Flexible tires do not twist. They should not have a high degree of gravity. Moreover, the degree of tension of all wires should be the same. The length of the tire may change under the influence of temperature. Therefore, rigid models are equipped with flexible jumpers that should compensate for these changes. In addition, they are equipped with vibration dampers.

In addition, electrical buses can be insulated or non-insulated. Already from the name it is clear that in the first case the tire has an insulation layer, but in the second it does not.

Classification of tires by section shape

According to the cross-sectional shape, electrical buses are divided into the following types:

• Tubular.

• Rectangular.

• Box-shaped.

• Two-way.

• Three-way.

Flat tires with a rectangular cross-section dissipate heat well. Their use is advisable in a network with high current strength (from 2 thousand to 4.1 thousand amperes). In such cases, they are combined into groups of several pieces. This creates a two- or three-lane bus.

Busbars have a number of disadvantages:

• It is difficult to carry out installation work.

• Inductive current that is distributed unevenly.

• Low ability to withstand mechanical stress.

• Reduced cooling capacity.

• Low short circuit resistance.

In a network with a voltage of 10-35 kilovolts, box-shaped or flat products can be used. The tubular one is considered the most effective. It has a number of advantages. It is durable and removes heat well. The electric field around it is distributed evenly. Thanks to this, coronation does not appear.

Types of material for making tires

Depending on the material from which the tire is made, the following electric tires are distinguished:

• Copper.

• Aluminum.

• Steel.

• Steel-aluminum.

The latter option is a core made of galvanized steel wires, around which aluminum wires are twisted.

Aluminum tires have the following advantages:

• Resistant to corrosion.

• They have a high electrical conductivity.

• Light weight.

• Their cost is lower than other types.

For their production, plastic materials with a minimum amount of impurities are used. Low alloys of aluminum, magnesium and silicon can be used. Additional elements allow you to increase strength, ductility, and elasticity.

Copper busbars can contain up to 99.9% copper. Such products are marked M1. The ShMT and ShMTV brands, which are produced from an oxygen-free grade, are widely used. They differ in the degree of softness. The first two letters of the marking ShMM and ShMT mean “Copper tire”. The following letter “M” characterizes soft products, “T” - hard ones.

Marking for three-phase alternating current

“Hints”, which are expressed in the color and letter designation of tires and wires, will help you identify the elements of electrical installations. They are not chosen randomly. They are regulated by standards.

There are two ways to color code tires. The first implies that the marking of electrical busbars is applied at the manufacturing stage. The manufacturer uses insulation of different colors. The second is suitable in cases where the product has one color. In such situations, colored electrical tape is used to mark different phases.

In the case of three-phase current, the marking will look like this:

• Phase “A” turns yellow.

• Phase “B” is colored green.

• Phase “C” is colored red.

Conductor designation

The grounding conductor is marked PE. It is always indicated in yellow-green color. The colors run in longitudinal lines. Moreover, the use of these two colors separately is prohibited by GOST. For the neutral and middle conductor (working) marked N, blue color is used.

When connecting neutral protective and working conductors, combine all three colors. The marking in this case looks like PEN. The conductor is blue, and at its end and at the connection points there is a yellow-green stripe. Currently, it is also possible to use the opposite color: a yellow-green conductor with a blue stripe at the end.

Letter marking

Electrical wires and tires with alternating current are deciphered as follows:

• L - conductor of a single-phase network.

• L with numbers 1, 2 or 3 - a conductor in a three-phase network.

• N - neutral conductor (or neutral).

• M - middle conductor.

• PE - grounding conductor (protective).

• PEN - combined neutral conductors (protective and working).

With direct current, the designations will look like this:

• L+ - positive (or positive) conductor.

• L- - negative (or negative) conductor.

All these markings and designations are mandatory. They are regulated by accepted regulations.

It’s difficult to remember all this at once. But an experienced electrician knows all this. This marking will allow you to determine where and what is connected. But this will be enough for an ordinary person to understand, for example, what kind of tire is needed for electric machines. It may be needed when repairing electrical wiring in the house. It’s easy to connect additional sources to it later.

Decree of the Government of the Russian Federation dated June 26. 1995 No. 610 p. 7 7. An educational institution for advanced training implements the following types of additional professional education: advanced training, internship, professional retraining. The purpose of advanced training is to update the theoretical and practical knowledge of specialists in connection with increasing requirements for the level of qualifications and the need to master modern methods for solving professional problems. Advanced training is carried out as necessary, but at least once every 5 years throughout the entire working life of employees. The frequency of specialists undergoing advanced training is established by the employer.
Advanced training includes the following types of training:

short-term (at least 72 hours) thematic training on specific production issues, which is carried out at the place of the main work of specialists and ends with passing the relevant exam, test or defense of an essay;

The main purpose of the internship is to form and consolidate in practice professional knowledge, skills and abilities acquired as a result of theoretical training. The internship is also carried out for the purpose of studying best practices, acquiring professional and organizational skills to perform the duties of the current or higher position. An internship can be either an independent type of additional professional education or one of the sections of the curriculum for advanced training and retraining of specialists. Internships for specialists can be carried out both in the Russian Federation and abroad at enterprises (associations), leading research organizations, educational institutions, consulting firms and federal executive authorities. The duration of the internship is established by the employer sending the employee for training, based on its goals and in agreement with the head of the enterprise (association), organization or institution where it is carried out. The purpose of professional retraining of specialists is to obtain additional knowledge, skills and abilities in educational programs that provide for the study of individual disciplines, sections of science, engineering and technology necessary to perform a new type of professional activity. Based on the results of professional retraining, specialists receive a state-issued diploma certifying their right (qualification) to conduct professional activities in a certain field. The direction of professional retraining is determined by the customer in agreement with the educational institution for advanced training. Professional retraining is also carried out to expand the qualifications of specialists in order to adapt them to new economic and social conditions and conduct new professional activities, including taking into account international requirements and standards. As a result of professional retraining, a specialist may be assigned additional qualifications based on the acquired specialty. Professional retraining to obtain additional qualifications is carried out through the development of additional professional educational programs. Requirements for the minimum content of additional professional educational programs and the level of professional retraining are established by the federal executive body implementing a unified state policy in the field of additional professional education, together with other federal executive bodies within their competence. The procedure and conditions for professional retraining of specialists are determined by the federal executive body implementing a unified state policy in the field of additional professional education.
Professional retraining and advanced training of specialists is carried out on the basis of agreements concluded by educational institutions of advanced training with executive authorities, employment service bodies and other legal entities and individuals. Professional retraining and advanced training of civil servants of federal executive authorities is carried out in the manner established by the Government of the Russian Federation.

Color designation and marking of wires in electrical wiring. Color of the phase, ground, zero wire.

Color designation of phase, grounding, neutral wires

[PUE-7]

According to the seventh edition of the PUE (2002, Ministry of Energy of the Russian Federation), electrical wiring must provide the ability to be easily recognized along the entire length of the conductors by color:

· bluecolors - to indicate zero, zero working or middle conductor of the electrical network (N);

· two-color combinationgreen- yellowcolors - to indicate grounding, protective or neutral protective conductor (PE);

· two-color combinationgreen- yellowcolors along the entire length withbluemarks at the ends of the line, which are applied during installation - to indicate the combined neutral working and neutral protective grounding conductor (PEN);

· black, brown, red, purple, gray, pink, white, orange, turquoise colors - phase, to designate a phase conductor(L).

Color designation according to functional purpose

[GOST 12.2.007.0]

Color identification of conductors according to the functional purpose of the circuits in which they are used (according to GOST 12.2.007.0):

· for conductors in power circuits color- black;

· for conductors in control, measurement and signaling circuits of alternating current color- red;

· for conductors in DC control, measurement and signaling circuits color- blue;

· for neutral protective conductors color - combinationgreen And yellow;

· for conductors connected to the neutral working conductor and not intended for grounding, color - blue.

Designation of wires by color

[GOST IEC 60204-1-2002]

According to GOST IEC 60204-1-2002 "ELECTRICAL EQUIPMENT OF MACHINES AND MECHANISMS" if color marking is used to identify wires, the following colors can be used: black, brown, red, orange, yellow, green, blue (including light blue), violet, grey, white, pink, turquoise.

Note- List of colors taken from IEC 60757.

For safety reasons, the colors green and yellow should not be used if they could be confused with a two-color combinationgreen- yellow.

The protective conductor must be easily recognizable due to its shape, location, marking or color. When using color designation, it should be a two-color combinationgreen- yellow. It is used along the entire length of the wire. This combination is intended for protective conductor only.

Two-color combination on insulated wiresgreen- yellowshould be such that over a length of 15mm one of the colors covers at least 30%, but not more than 70% of the surface of the wire, and the other color covers the remaining part.

When the protective wire grounding easily distinguishable due to its shape, design, location (e.g. braided wire) or when insulated wire is not easily accessible, color coding is not necessary along the entire length. However, ends or accessible parts must be clearly markedgraphic symbol 417-IEC-5019 or two-color combinationgreen- yellow.

When a circuit includes a neutral wire, indicated by color, the latter must belight blue(IEC 60446, 3.1.2). Where possible, light blue should not be used to indicate other wires.

In the absence of a neutral wire, the light blue wire can be used for other purposes, but not as a protective wire.

When color coding is used, non-insulated wires used as neutral wires should be marked with a light blue stripe with a width of 15 to 100 mm , a color that is duplicated on every shell, equipment, or available location, or is painted a light blue along its entire length.

Identification of other wires should be carried out using color (either as a whole, or in one or more stripes), numbers, letters, or a combination of these. The numbers must be Arabic, the letters must be Latin (uppercase or lowercase).

Insulated unipolar rigid wires must have the following color designation:

· black- AC and DC power circuits;

· red- AC control circuits;

· blue- DC control circuits;

· orange- interlock control circuits powered by an external energy source.

Exceptions to the above are permitted:

· for internal cables on independent devices, purchased separately with a complete set of cables;

· when the insulating material used cannot be painted in the required colors;

· when multi-wire cable is used, except for the green-yellow two-color combination.

With single-phase alternating current, bus B, connected to the end of the power source winding, is in red, bus A, connected to the beginning of the power source winding, is yellow.

Single-phase current buses, if they are a branch from the buses of a three-phase system, are designated as the corresponding three-phase current buses;

Ticket No. 16

2. Face and eye protection during operational switching (2.3.12-2.3.14;II- Vgr.)

Before use, safety glasses should be inspected for scratches, cracks and other defects; if any are found, the glasses should be replaced with good ones.

To avoid fogging of the glasses, when using glasses for prolonged work, the inner surface of the glasses should be lubricated with PA lubricant.

If glasses become dirty, wash them with warm soapy water, then rinse and wipe with a soft cloth.

Ticket No. 17

3. Requirements of the Rules for trolleys with voltage up to 1.0 kV(PUE 5.4.17-5.4.40;II- Vgr.)

The repair section of the main trolleys must be electrically isolated using insulated joints from the continuation of the same trolleys and connected to them through disconnecting devices in such a way that during normal operation this section can be switched on to voltage, and when the crane is stopped for repairs, it can be reliably disconnected.

The insulation of the joints of the main trolleys should be made in the form of an air gap, the width of which depends on the design of the current collector, but should be less than 50 mm at voltages up to 1 kV. The width of the current collector must be such that during normal operation of the crane, interruptions in the supply of voltage and its unexpected stop when the current collector crosses isolated trolley joints are excluded.

Disconnecting devices used to connect the repair area with the continuation of the main trolleys must be closed and have devices for locking in the off position.

The repair section of the main trolleys, located at the end of the crane span, must be equipped with one insulated joint and one disconnecting device.

The repair section of the main trolleys, located in the middle of the span, must be equipped with two insulated joints (one on each side) and three disconnecting devices switched on in such a way in such a way that it is possible to provide continuous power to the trolleys, bypassing the disconnected repair area, and the trolley sections located on both sides of it.

On the main trolleys, and in the case of their sectionalization, on each section of these trolleys and on each of their repair sections, it must be possible to install a jumper that short-circuits with each other and grounds all phases (poles) for the period of inspection and repair of the trolleys themselves or repair of the crane.

Trolleys can be rigid or flexible; they can be suspended on cables and located in boxes or channels. When using rigid trolleys, it is necessary to provide devices to compensate for linear changes in temperature and settlement of the building.

The flexible cable used to power the crane's electrical equipment must be suitably protected in areas where it is susceptible to damage. The choice of cable brand should be made taking into account its operating conditions and possible mechanical stress.

In places where cargo ropes may come into contact with the trolleys of this crane or a crane located one tier below, appropriate protective devices must be installed.

The main trolleys must be equipped with a light alarm indicating the presence of voltage, and when trolleys are sectioned and there are repair areas, each section and each repair area must be equipped with this alarm.

The main trolleys of the rigid type must be painted. except for their contact surface. The color of their painting should be different from the color of the building structures and crane beams, and red is recommended. At the power supply point, at a length of 100 mm, the trolleys must be painted in the appropriate color.