Assembly order

After obtaining permission to connect the three stages and technical conditions, we proceed to self-assembly of the shield.

The inserts will be mounted in a sealed box, which must be assembled on the outer wall of a private house, pipe rack or on a support (as it is commonly called, on a column). It has a three-phase meter and a circuit breaker as shown in the picture below:

But more often the measuring plate is mounted behind the fence of private houses, on supports. Depending on how it is organized, the grounding system.

Near the support, they are installed on the ground, mounted on the body of the electrical panel and reconnect the PEN conductor of the high-voltage line (according to PUE 1.7.61, Chapter 1.7) It is recommended to install the primer before the meter, in this case it is installed in an additional box inside The control panel is sealed.

They do this because organizations supplying electricity must ensure that the meter cables cannot be connected. Here is the division of the PEN into PE and N. To do this, take two buses, connect PEN to one of them, and connect the second with a jumper to the first, so it turns out that you now have two buses PE and N, and PE and N are no longer connected to each other in other sections of the circuit. The organization of the grounding system is called TN-CS.

The electrical circuit of the measuring board is described in the technical specifications.

If the metering panel is already installed and you have access to 2 wires (for a single-phase circuit) or 4 wires (for a three-phase circuit) going to the house, they make a switchboard at home. They also make a grounding switch, but they actually regulate the TT system, that is, the PE is not connected to zero of the SCH.

Assembly instructions for the three-phase switchboard

If 3 wires from the control panel for single-phase input come to you, and 5 wires for three-phase input, then you no longer need to make a grounding switch, you have already organized a power supply via the TN-CS or TN-S system.

As you can see, situations vary and need to be clarified in the installing organization about the purpose of the cables and the recommended grounding system.We have just provided examples of different situations to help you decide what to do.

But in any case, you need to understand that three- or four-pole circuit breakers are used to connect three-phase equipment, as shown in the diagram below:

The 380V measuring panel is assembled with a wire with single-wire connectors (monolithic), or multi-wire connectors (flexible), but in the latter case the tips nshvi are crimped. Recommended colors are L1 red, L2 white, L3 black, N blue, PE yellow green.

To properly assemble a three-phase shield, you need to carefully consider the protective devices on which phase markings are applied for connecting the wires. This diagram shows four-pole RCD protection devices, with an additional terminal, in normal devices this terminal may be absent. In turn, the devices mounted in the panel on the DIN rail start moving, we measure the wire from terminal L1 to terminal L1 of the device that follows, with a margin of 30%, for ease of installation and operation.

We carry out such an operation with all terminals, however, note that it is not recommended to cut the pieces in advance, because the process may not be long enough for a comfortable connection. It is best to assemble the shield using a three-stage rail, which will save space and reduce the chances of confusing something. We separately put the zero bus and the PE bus, which are necessarily connected to the casing of the metering board.

If you do not have three-phase equipment in your apartment or house, you need to assemble a 380V panel so that each phase is uniformly loaded with single-phase consumers. An example of such an assembly of a three-phase electrical panel in a private house you can see below:

In this switchgear scheme, the phases are distributed to a separate load through single-pole circuit breakers and differential switches. L1, L2 and L3 are uniformly loaded by consumers, according to the previous rated load. Learn more about how to distribute the load in stages from our article.

It is not recommended to do – one phase for outlets, another for lighting, and a third for any other needs, because it is important to distribute the load between L1, L2 and L3. This is important, especially if the VLEP is in poor condition and phase misalignments are likely. Yes, and even load distribution increases the stability of the home electrical system and reduces the risk of hitting the input machine due to overload in one of the phases.

To protect yourself from the effects of phase imbalance, install a voltage monitoring relay for both single-phase and three-phase networks. You can control the load distribution using a multimeter with current clamps, which is shown in the photo below.

Well, the last option of assembling a 380 V electricity metering panel is mixed , when there are three-phase and two-phase electricity consumers in the home electrical network. In this case, you can assemble the electrical panel as follows: