Requirements for the designation of the grounding sign in electrical installations

Location on the equipment

Depending on the type of electrical equipment, GOST standardizes the marking option and the place on the housing where the connection to ground should be indicated:

1. Grounding symbol near the clamp/clip on the shield. According to paragraph 6.4.6 of GOST R 51778 of 2001, the designation must be located at the clamp. Additionally, a sign marks the place where the neutral protective conductor PE is connected.
2. “Grounded” sign next to the connection between the metal parts of the housing and the PE conductor. The option is due to the requirements of safety rules 08-624-03. A sticker can be glued to the case or the corresponding symbol can be engraved directly into the metal.

Important! The grounding sign is applied to the surface of the electrical panel in any indelible way. The junction of the grounding cable and the shield itself is cleaned of corrosion, and some of the paint is removed from the connected area.

In what places is the grounding sign applied?

Signs indicating grounding are also used in drawings when drawing up project documentation. They are applied separately, along with switching equipment, control systems and lines connecting them to each other.

Special signs - tags are placed directly on the housings of electrical equipment, next to the main grounding buses of substations and power plants, on the doors of distribution boards near the contact with the fixed grounding wire and the point of connection to the grounding conductor.

The main function of grounding systems is to ensure the safety of electrical installations. In turn, the grounding symbol is intended to indicate the exact location of the connection between the equipment and the circuit. Special symbols are applied directly to the connection point of the protective conductor to the grounding bus, as well as next to the terminals or studs through which the wire is connected to the switchboard housing.

The grounding sign can be applied in any way that ensures its resistance to abrasion during operation. The entire area with which the grounding conductor will be in contact must be cleaned of corrosion, and all paint must be removed from the connected tip of the conductor.

Options for marking electrical equipment

Most often, a symbol or letter designation is applied to the shields or control panels directly at the manufacturer. The designation location has a convex or depressed relief surface. On new production lines, the “grounded” sign on the shields is cast directly during the manufacture of the metal or plastic housing.

Regardless of whether there is an embossed marking or not, the ground symbol is additionally colored for visual highlighting on the surface of the housing.

For old electrical appliances, production usually simply uses a grounding sign sticker, which is glued to a special adhesive compound or using adhesive tape. As a result, it is possible to quickly mark all the panels and significantly save money. It is worth noting that the use of a grounding symbol in the form of a sticker does not contradict the current GOST.

What does a grounding sign look like?

The task and features of grounding transformers.

The grounding sign (ЗЗ) appears as a black symbol on a bright yellow background. The logo icons must be located next to the grounding bus mount. According to GOST ZZ, they must have a certain type of execution. Methods for applying and installing glazing can be completely different.

Metal plate

The manufacturer itself installs a logo on its products in the form of a convex or depressed image on a metal plate. The plaque is either screwed on or welded using spot welding.

Sticky symbols

GOST does not prohibit the use of stickers. Typically, these emblems have an adhesive backing. Remove the protective film from the back of the sign and press it to the clean surface of the body in the right place. The sticker must be ironed with a rag or a clean cloth so that no air bubbles remain under the sign. If this is not done, the sticker may come off over time.

Sticker near the bus terminals

Adhesive signs are made using high quality materials. This allows them to be used in conditions of significant vibration and high humidity levels.

Cast images

When manufacturing a flask for casting housings of electrical devices, the manufacturer inserts a template with a grounding logo into the casting mold. ZZ is obtained in the form of a relief imprint on the body of the equipment casing.

In this case, the sign is painted by hand with black and yellow enamel. The painted surface is periodically updated. GOST 21130-75 prescribes a clear execution of the design, indicating the detailed dimensions of the design elements. This applies not only to metal, but also to plastic cases made by injection molding.

Dimensions ZZ

Stamp

Drawing images using the stamping method has been used for quite some time. Most often, the method is used in the manufacture of non-ferrous metal cases. The dimensions of the stamped ground symbol detail are slightly different from the cast ones. They are indicated in the table of the same GOST 21130-75: this is the diameter of the circle, the length and thickness of the lines, the angles of the figure, etc.

Important! In both cases, the edge of the circle and the logo itself are most often painted with radical black paint, while the field of the sign itself is bright yellow or orange.

How is grounding indicated in diagrams and drawings?

When designing electrical circuits on a production line, not only structural elements, switching devices and control equipment are marked, but also the location of the ground loop.

The regulatory document, which specifies all the features of the sign designation on the diagrams, is GOST 2.721 of 1974. Designation of a silent and protective version of grounding signs in the drawings

Important! To select the correct symbol, special attention must be paid to the characteristics of the equipment to be grounded. Depending on the type of grounding, alphabetic symbols (N, PE, PEN) are added to the icon.

Grounding signs on electrical diagrams

Grounding calculation

The depiction of 3Z on electrical diagrams is regulated by State Standard 2.721-74 and the Unified System of Design Documentation (ESKD). They are mainly guided by 4 types of images:

1. In the first case, the drawing consists of one vertical and three horizontal lines. This is the most commonly used symbol in electronic circuits. Previously, an image in this form was mandatory. It concerned the designation of the installation of a protective connection between conductors and ground;
2. The second type of sign repeats the previous one, but the symbol is enclosed in a circle with a segment cut off from the bottom. It is used for stand-alone equipment that is not included in the overall protection system of neighboring installations. That is, this equipment requires a separate connection to the ground loop;
3. The third symbol is the same sign, but in the whole circle. Basically it means grounding of current-carrying elements that are in a normal state without voltage;
4. The fourth image somewhat resembles a rake. This must be understood as the connection of current-carrying parts of the installation with the “ground” circuit through the equipment body. This type of grounding is not complete protection.

Note! The dimensions of grounding signs must comply with the requirements of the ESKD and not exceed the size of the remaining elements of the circuit.

Guided by GOST 21130-75, the points of attachment of protective busbars on electrical equipment housings are determined and the markings are updated in a timely manner. This guarantees safe operation of power plants. Knowledge of the types of electrical circuits allows you to understand and draw the correct electrical circuit.

Dimensions of the grounding sign according to GOST 21130-75

The specified GOST specifies not only the dimensions, but also the methods of applying the sign on the equipment of the manufacturer of panels and other electrical equipment. 4 types of designation are regulated:

1. Stamping method.
2. Casting in steel case.
3. Impact method.
4. Pressing method in plastic cases.

Clause 3.1 of the above GOST specifies the possibility of making signs using appliqué, paint, or photochemical methods. The only strict requirement is their size:

• When casting or pressing on the body

• When manufactured using the impact method

Important! The color of the circle of the sign must be noticeably different from the outer surface of the equipment housing. The background is usually painted yellow, and the relief along the contour is made in black or dark gray shades.

56-0010, Electrical safety sign stickers “Grounding” d - 20 mm (20 pcs per sheet)

Electrical engineering\Accessories for cabinets and panels\Electrical safety signs

The set of electrical safety signs “Grounding” consists of 20 round stickers, each of which is 2 centimeters in diameter. These signs are intended to confirm the safety of electrical equipment. Protective grounding is the intentional electrical connection to earth or its equivalent of metallic non-current-carrying parts that may become live. This marking complies with modern standards.

• The mark is clearly visible and retains its bright colors for a long time, even with constant use. • Has good resistance to lubrication, resistance to direct sunlight, temperature changes, and minor mechanical impacts. • Made of durable, wear-resistant material, easy to glue, holds tightly and leaves no marks after removal (* intended for application to a flat, dry surface).

Specifications: Product type: sticker (PVC film with semi-gloss surface, paper backing) Set included: 100 stickers with diameter (d) 2 cm (5 sheets of 20 stickers each) Self-adhesive: yes Format: circle Image: picture Color: yellow, black Country of origin: Russia
The set of electrical safety signs “Grounding” consists of 20 round stickers, each of which is 2 centimeters in diameter. These signs are intended to confirm the safety of electrical equipment. Protective grounding is the intentional electrical connection to earth or its equivalent of metallic non-current-carrying parts that may become live. This marking complies with modern standards. • The mark is clearly visible and retains its bright colors for a long time, even with constant use. • Has good resistance to lubrication, resistance to direct sunlight, temperature changes, and minor mechanical impacts. • Made of durable, wear-resistant material, easy to glue, holds tightly and leaves no marks after removal (* intended for application to a flat, dry surface). Specifications: Product type: sticker (PVC film with semi-gloss surface, paper backing) Set included: 100 stickers with diameter (d) 2 cm (5 sheets of 20 stickers each) Self-adhesive: yes Format: circle Image: picture Color: yellow, black Country of origin: Russia

Marking of grounding bars

Comparison of materials

PVC premium

PVC premium products are designed for use in difficult conditions, thanks to a special solvent-based adhesive with a high level of initial and final adhesion. The product adheres tightly and reliably to complex, rough and embossed surfaces, polyethylene (including foam), polypropylene, polyurethane, shagreen powder coating, etc.

PVC uv premium

PVC uv premium products are designed for use in particularly difficult conditions. They are distinguished by a special adhesive layer that creates maximum adhesion even with complex, rough and embossed surfaces. They are tightly glued to polyethylene (including foam), polypropylene, polyurethane and shagreen powder coating. It differs from the PVC premium version by an additional PVC coating that provides long-term protection from mechanical, chemical influences and active ultraviolet radiation.

*Measurement values ​​shown are average values ​​for informational purposes only; actual values ​​may vary depending on specific application conditions. For more detailed information, it is recommended to contact TARGIS technical support service