We are constantly confronted in our home, office and industrial premises with electrical appliances, which are conductors of electrical current. These can be central heating batteries, gas stoves, bathtubs, pipes, etc. Such conductors have an electrical potential of various sizes with a rather high value.
- 1 About potential difference
- 2 Equipotential bonding boxes
- 3 Types of installation
About potential difference
If the magnitude of the potentials of the conductive objects in the room is different, then between them voltage occurs (potential difference), which represents a greater danger of electric shock to person It is especially important to take this into account when connecting appliances in rooms with high humidity (sanitary rooms, shower rooms).
Electric potential difference household appliances and pipes in the apartment may appear as a result of:
- current leakage due to damage to the insulation of wires;
- improper connection of electrical equipment;
- faulty electrical appliances;
- manifestations of static electricity;
- the occurrence of stray currents of the grounding system.
In order to prevent the occurrence of a potential difference in the room, equipotential bonding system (SUP) - parallel connection of all metal structures in the house. The basis of the EMS is the integration of conductive objects into a single circuit.
The building provides for the installation of both the main ground loop and additional potential equalization systems in accordance with the requirements of modern rules and standards of construction. The main system includes metal structures of the building: fittings, ventilation ducts, pipes, parts and elements of elevators and lightning protection.
Engineering communications have a fairly significant length, which increases the resistance of conductors. In this case, the electric potential of metal pipes on the upper floors of a high-rise building is much greater than that of a pipeline on the first floors.
In addition, recently metal pipes are beginning replace with plastic. Thus, batteries and towel warmers, which are made of metal, are deprived of protection, since plastic is not a conductor and has no connection to the ground bus. Therefore, to solve such problems, an additional potential equalization system (DPPS) is installed.
Equipotential bonding boxes
The potential equalization box (PSC) is one of the elements of the system for protecting people from the danger of electric shock. The device is used when organizing a DPMS in a room (office, apartment, house, etc.).
There are different types of PMC depending on the building structure:
- in hollow walls;
- in solid walls;
- open installation.
Types of installation
Installation of PMC for metal pipes
The PMC is a plastic case where the internal tire is placed - the most important part of the grounding device. It connects conductors with metal pipes of hot and cold water supply, gas supply, sewage, heating, as well as electrical appliances located in the room. The grounding wires from sockets and switches are connected to the box. From the internal bus diverted conductor to the flat panel, through which the connection is made to the main grounding bus, located at the entrance of the building.
Installation of PMC for plastic pipes
When installing plastic pipes, metal taps and mixers are connected to the SUP. Also, plastic pipes can have dielectric inserts that are connected to the main office.
The system provides the same potential of all metal elements in the building. In the event of a voltage on any object, it will move through the grounding conductor to a common circuit.
The distribution box is installed in such a way that it does not violate the interior of the room. At installation of systems it is necessary follow certain rules:
- installation of the PMC is made in the place of the risers;
- free access to the PMC is provided;
- obligatory connection of all accessible open elements of electrical equipment, as well as protective conductors and third-party conductive parts;
- installation of the system in the bathrooms, bathrooms is carried out on a mandatory basis.
SUP create in the process of building a house. If it is absent in old buildings, the installation of such equipment is carried out for electrical safety purposes. In order to efficiently and safely carry out installation of the PMC, the building grounding system is preliminarily studied.
In some cases it is prohibited to install the PMC. So, if at the entrance the grounding circuit was installed without a grounding conductor, then the equalization of potentials cannot be done. Therefore, this work should be assigned only to specialists.