Sealing a circuit breaker: technical requirements and legislation

Sealing the input machine in the control panel

At the entrance of power supply lines to various objects, buildings, structures, residential or industrial, introductory automatic machines are installed in distribution boards. After which, electricity is distributed among sockets, lighting groups, to individual high-power devices and others. In the same distribution boards, an electricity consumption metering unit is installed. In most cases, such distribution boards are the point of balance between the consumer and the electricity supply organization.

Why do you need sealing of the input switch?

An input switching device is installed before the meter; it can even be a simple switch with a fuse box. But in most cases, modern networks install a difavtomat or a protective circuit breaker. The input machine and the meter are on the balance sheet of the energy supply organization and are sealed by their representative.

An example of installing a distribution cabinet on the wall of a building and placing a metering unit with a water circuit breaker in it.

To prevent unauthorized connection to the meter for the purpose of stealing electricity, the terminals with the contacts of the meter and the input machine are securely closed and sealed. The seals are placed by a representative of the organization that supplies electricity, and a balance sheet demarcation act is drawn up. The electricity consumer is responsible for all elements of the electrical network after the meter. The designs of meters and input machines can be different, so when sealing, these features must be taken into account.

How to seal an introductory machine: methods

No rule provides for mandatory sealing of input machines. But despite this, this type of protection is currently being used more and more often.

Ways to seal input machines:

• The seal is placed directly on the shield;
• A sealable box (box or box) is used;
• Sealable terminal cover;
• Stickers.

The simplest way is to seal the input panel in which: automatic machines, RCDs, meters and other equipment are installed. But this type of sealing is not the best option, since at any time you may need access directly to the installed equipment. This could be replacing devices or making additions to the circuit.

But unlike conventional switchboards, which are not intended for sealing, there are specialized switchboards in which the input circuit breaker is installed and sealed separately.

Nowadays, a sealing box is often used, through which the machine is sealed separately from the rest of the chain elements. There are two main types of boxes: for mounting on a flat surface and for mounting on a DIN rail. For sealing, there are special ears on the box body.

All presented types of seals for circuit breakers meet the requirements of service organizations.

Also, to seal the machines, plugs are produced that are installed on the terminals of the automatic device and block access to the clamping terminal of the machine. These plugs are sold separately from the machines. There are machines with sealable covers, and input circuit breakers with plugs included. It all depends on the manufacturer.

Inspectors of service companies often began to use stickers as seals. They are glued to the clamping mechanisms of the machine, thereby sealing them.

Types of fillings

A seal is considered a disposable element that allows you to verify the fact of unauthorized entry into a protected object. They increase the effectiveness of a number of organizational and practical activities:

• Eliminate or minimize energy losses;
• Make a more efficient system for accounting for electricity consumption;
• At production facilities they have a positive effect on work culture and discipline.

The main task of the filling is not to be able to remove it without external factors of damage, which will be immediately noticeable. All types of fillings can be divided according to the following characteristics:

• Material of manufacture;
• Constructions;
• Operating principle.

A cable seal can be used as a lock; the strength, flexibility and length of the cable allow it to be threaded through misaligned holes in cabinet doors or hinges. The cable is pulled through a plastic destructible housing with an individual number.

The UNISIL plastic seal has a tightening design with a reliable lock, which has a metal insert with four petals, and has a pressed individual number on the plastic surface.

KRABSIL – a metal seal in the form of a clip, fixed with a spiral wire, an individual number is pressed onto the surface of the clip;

EDSIL-N is a plastic seal, actually an analogue of the UNISIL brand

Lead and polyethylene seals - have a diameter of 10 or 16 mm2, a cylindrical shape through the holes of which a wire is passed, after which the entire structure is pressed with a seal with an imprint of a number or other individual sign.

Sealing stickers have a special chemical composition of the adhesive layer; when the sheet is removed from the surface, it makes no sense to stick it in its original place, the inscription “Opened” or “Opened, Draw up a report!” appears.

Several types of reverse-type numbered plastic seals

Numbered plastic seals – have a cylindrical transparent body with an individual number. The seal is attached to a wire loop, secured with a plastic latch or a rotating mechanism, after which the rotary flag is broken off.

• Price: 1.88 UAH. – 4.7 rub.

To seal elements of electrical installations, plastic or lead seals are most often used.

Sealing of the control panel

The easiest way to limit unauthorized access to the contacts of the input circuit breaker is to seal the switchboard door.

One of the options for sealing the distribution cabinet

But this method is not always convenient for the consumer of electricity if the distribution cabinet contains circuit breakers for individual network groups and other elements. Every time you need to service equipment or during operation, if you need to turn off certain groups or elements of equipment, you will have to call a representative of the energy supply organization. Therefore, other methods are more often used that less restrict the freedom of action of electricity consumers.

Plastic plugs

A common way to seal a circuit breaker is with plastic plugs. This is the most modern method, providing not only protection against theft, but also against electrical shock. They are made from non-flammable plastic and have two parts.

The plug is disassembled. The input circuit breaker is sealed using a plug. It has two parts.

First, the first part is placed in a special hole in the machine, then the second part is placed, which expands the plug inside the machine and is securely fixed in the machine. Then comes the installation of the seal.

In this case, it can be sealed using wire and a seal. There are plastic seals for one-time use only. But not all machines can be sealed this way.

Since older models were produced without special ones. The slots are needed to secure the plug. When purchasing a machine, pay attention to the setting device or switch.

Sealing of input switches in plastic boxes

The circuit breaker is mounted in a plastic box inside of which there is a special DIN-rail type fastening on the bottom.

Installation sequence:

• The lower component part is attached with self-tapping screws or bolts to the rear wall of the switchboard or is generally moved outside the switchboard body.

Circuit breaker in plastic box

• A circuit breaker is installed on the mount;

• The wires are started and connected;
• The top cover with a loop for the seal is applied and fixed, where the through holes in the lower part of the substrate and the top cover of the case are aligned.
• A wire or fishing line is passed through the holes, connecting the seals with a loop to both parts, after which the remaining sealing operations are carried out depending on the model of the seal. A sealer is used, the plastic flag is turned and broken off, or the loop is simply tightened through a one-sided lock.

An example of installing an input switch in a plastic box near the meter inside the switchboard.
Thus, only the switch lever remains accessible, the terminals are securely closed with a plastic box, unauthorized access without breaking the seal is excluded.

Introductory machine: 4 characteristic qualities

An input machine can be purchased on the Internet or in a specialized store. When electrical networks operate, various overloads or voltage surges are very often observed. These factors undoubtedly affect the operation of individual household appliances, machines and units in production. Also, an unstable supply of electricity can affect the operation of electricity meters installed in each home. Therefore, to protect against these factors and ensure optimal operation of devices, circuit breakers are installed.

Automatic switches are devices that are installed in front of the electric meter at the input of electricity to various objects, such as apartments, private houses, garages and buildings.

There are several types of introductory machines:

• Single pole;
• Bipolar;
• Three-pole;
• Four-pole.

Automatic input switch is a technical definition of the product; it is popularly called an input automatic switch. This name also indicates that the machine in the electrical circuit of the object is located closest to the source of electricity.

When installing an input circuit breaker, you must follow safety regulations

Unlike other automatic devices, this product has one distinctive feature - an increased rated operating current. The most commonly used are two- and four-pole circuit breakers.

For domestic use, the rated voltage of circuit breakers is 25 - 32 Amperes.

Input circuit breakers are selected according to several parameters, the main one of which is the maximum value of short circuit current (SC). Also, when choosing input switches, take into account the number of phases involved in the operation and the power consumed by the facility.

For residential and facilities with low power consumption, one or two-phase circuit breakers are installed. But, since phase and zero must be forced to break, two-phase machines are more often used.

Tech and four-phase, are used as a protective device for connecting various units, motors and equipment. To automatically break both phases and neutrals, four-phase circuit breakers are used.

ABB input machine: connection diagram

The first and most important rule when working with electrical equipment is the absence of voltage in live conductors. Different electrical experts connect these machines in their own way, since the connection diagram prescribed by the manufacturer is a recommendation.

Connection types:

• Through the fixed contacts of the machine;
• To the moving parts of the machine.

From a technical point of view, both connection options are correct, but in this way, the machines can only be connected to an alternating current network. The machines are connected to the DC network only through fixed contacts.

The fixed contact is the terminal located at the top of the circuit breaker.

Connecting a two-phase machine is as follows. The switch is installed on a DIN rail by simply pressing it. Next, the wires coming from the meter are stripped to the height of the clamping terminal (approximately 10 mm) (first the electrical circuit is assembled inside the panel) and clamped into the corresponding (lower) terminals. Then the phase and neutral wires of the input cable are stripped, and the machine itself is connected.

When connecting wires, make sure that no wire insulation gets into the clamping terminal.

The connection diagram for the ABB input machine can be downloaded and printed on a printer for ease of use

Connection of three and four-phase circuit breakers is made by connecting three phases and a neutral wire to the terminals of the machine. The neutral terminal is marked with (N) and is usually located on the right.

How to seal an introductory machine: methods

No rule provides for mandatory sealing of input machines. But despite this, this type of protection is currently being used more and more often.

Ways to seal input machines:

• The seal is placed directly on the shield;
• A sealable box (box or box) is used;
• Sealable terminal cover;
• Stickers.

The simplest way is to seal the input panel in which: automatic machines, RCDs, meters and other equipment are installed. But this type of sealing is not the best option, since at any time you may need access directly to the installed equipment. This could be replacing devices or making additions to the circuit.

But unlike conventional switchboards, which are not intended for sealing, there are specialized switchboards in which the input circuit breaker is installed and sealed separately.

Nowadays, a sealing box is often used, through which the machine is sealed separately from the rest of the chain elements. There are two main types of boxes: for mounting on a flat surface and for mounting on a DIN rail. For sealing, there are special ears on the box body.

All presented types of seals for circuit breakers meet the requirements of service organizations.

Panels with a compartment for placing an input circuit breaker

Considering the need for sealing, many manufacturers of RShch, RSh, RU make a compartment inside for installing an input machine, which is closed by a front panel with elements for installing seals. The remaining devices have free access for maintenance personnel.

Option of an accounting distribution board with placement of compartments for various purposes

A very convenient distribution board, on the left side there is a metering unit, below there is a compartment for input machines, all elements are sealed by representatives of the energy supply organization. The right side belongs to the electricity consumer; if necessary, it can also be sealed by the official responsible for electrical facilities.

Methods for sealing input machines

There are 5 common methods of sealing input machines:

Sticker seal. To protect the contacts of the circuit breaker from unauthorized interaction, special adhesive seals are glued over the front surface. Their peculiarity is such that if you try to peel off or damage the sticker, the inscription “OPENED” will appear in place of the sticker. In this case, restoring the original appearance of the seal is impossible, and the next control check of the energy supply organization will reveal an attempt at manipulation.

Sticker seal in various degrees of damage Source aplomba.ru

Complete sealing of the distribution board. In the case where the distribution board is not equipped with an electricity meter, the energy supply organization prefers to seal its door, preventing unauthorized access to the inside of the housing. In this case, the above-mentioned sticker seals are most often used.

An example of sealing a panel door using a bag seal Source caam.ru

Sealing the box. Sometimes a single input circuit breaker can be used to protect an electrical circuit. In this case, it is located in a plastic box, which is sealed with various types of seals, including: numbered, power, disposable, snap seals and others. For this purpose, there are special “ears” on the body of any box.

The energy supply company sealed the circuit breaker box Source spb.masterdel.ru

Plastic plugs for terminals. A relatively new, but rapidly gaining popularity method of sealing introductory machines. The plug is inserted into the slot on the body of the machine, thereby closing the hole in the head of the pressure screw that secures the conductors in the contact of the machine. The end of the plug has a hole through which a steel wire is passed, which is secured with a numbered seal.

Special electrical panels. In order to unify and quickly install electrical distribution networks, a special line of metering and distribution boards (ShURn, ShchURv) was developed. The boards are equipped with a special compartment for the input machine, which can be sealed with all common types of seals.

Appearance of uninstalled and installed plugs Source asberg.ru

Sealing the input circuit breaker with plastic plugs

Some consumers, knowing the customer requirements, immediately produce circuit breakers with plastic plugs for the contact terminals. This greatly simplifies the filling process; there is no need for a separate compartment or plastic box.

An example of sealing a machine with plastic plugs

The installation process is obviously simple:

• installed an automatic machine,
• connected the wires;
• I covered the terminal holes with plugs and sealed them.

Each machine manufacturer makes appropriate plastic plugs for the design of their models.

Included with the BA47-29 machine from IEK, the plugs are attached to a plastic tire like leaves on a branch

If installation is necessary, they can be easily broken off and installed in the corresponding slots above the holes in the switch terminals.

An example of installing a plastic plug for a BA47-29 circuit breaker from IEK

After installing the plug, the hole for the clamping bolt of the terminals is securely closed; it is impossible to unscrew the screw for connecting the wires without removing the plug.

A typical mistake when sealing using this method is when they think that a plastic plug is enough to prevent unauthorized connection. When removed, a damaged plug can be replaced with another; these models do not have a license plate.

For reliability, the installed plugs in the modular block of machines are connected with a loop of fishing line or wire and sealed with any seal of a suitable design of this type.

Sealing switches with stickers

This is probably the simplest and most effective way.

This figure shows the entire complex of effective protection elements of sealing stickers

The right part of the sticker is torn off and pasted into a magazine with an account, the rest of the sticker seals the holes above the terminals and the seams connecting parts of dismountable housings.

When you try to remove such a sticker and install it back, the inscription “Opened” appears; there are many options for stickers in this case for imported ones, so the inscription “ OPEN VOID ”.

An example of sealing the input switch terminals with stickers in the control panel

One of the frequently asked questions

Why is there a sensitive magnetic sensor on the sticker?

Indeed, in the case of sealing input circuit breakers, it is not required. But sealing stickers are universal; they are used to seal electric meters, water consumption devices and others, where some wise men try to disrupt their operation using magnets.

1. Installing a power limiter (diagram)
2. Installation of a solid state relay (installation diagram)
3. Connecting the overcurrent relay
4. What to do if the electric meter is self-propelled (reasons)
5. Installation of a meter through current transformers (circuits)

Plastic box

The plastic box is made of self-extinguishing polymer. With its help, you can make a seal and protect yourself from illegal theft of electricity and access to the terminals of the device. It looks like a box and is installed separately from the meter.

It also has stamped holes for connecting wiring, which easily breaks off at the mounting location. This box has two parts. It can be installed either separately from the meter or inside on a rail.

The device for installation separately is equipped with a rail on which the input circuit breaker is also installed. To seal it, the reverse part of the box is attached to the top and then the seals are inserted.

The box for internal installation also has two parts. The principle of sealing is no different from external installation.

There is no big difference between these two methods, but it is recommended to install a circuit breaker inside the panel near the meter. This method is more convenient.