Content:
- What is important to know?
- Overview of circuits
What is important to know?
Before proceeding with the installation of the device, you must read the rules color-coded wires. In accordance with the requirements of the PUE, the following procedure for marking conductors by color is adopted:
| Appointment | Colour | Letter designation |
| zero worker | blue | N |
| Zero worker and protective (combined) |
Blue, with yellow-green stripes at the ends | PEN |
| Zero protective | Yellow green | PE |
| phase | yellow | A |
| phase | green | V |
| phase | Red | WITH |
Overview of circuits
The installation of a four-pole RCD module is based on the same principle as for a two-pole device used in single-phase power grids. The manufacturer attaches a passport to the product, which shows the most common circuit for connecting a residual current device to a three-phase network using a neutral. For ease of installation, the connection diagram is shown on the module case and looks like this:
The wiring diagram for connecting a four-pole RCD to three phases is simple and accessible to a person who does not have the qualifications of an electrician. Three phases of the 380 volt mains supply and a zero working conductor are connected to the four input terminals of the device.
The conductors coming out of the four output terminals are connected to the distribution network of a house, apartment, summer house or garage. Taking into account the fact that 3 phases (A, B, C) supply electricity to devices designed for 380 volts, and each separately the taken phase in combination with the neutral wire N provides power for a group of single-phase consumers 220 volt. A three-phase 380 volt network can be connected to an electric motor of a pump, compressor, concrete mixer, to a lathe or a welding machine. Further connection to one phase is made through circuit breakers.
To protect against leakage currents in the 220 volt network, it is necessary to provide for the connection of single-phase RCDs or differential circuit breakers. Usually, these protection devices are installed in places saturated with electrical appliances, as well as in rooms with high moisture content: in a kitchen or workshop, in a bathhouse or bathroom. For the convenience of electrical installation work, repair and maintenance, it is advisable to bring the neutral conductor N to the zero bus located in the switchboard, as shown in the diagram below:
The three-phase RCD module is mounted in the input device panel on din rail, as well as machines, is equipped with quick-release fasteners. Connection occurs after the meter. One three-phase leakage current protection device can be used to protect three single-phase networks at once.
Before connecting a four-pole RCD in the house, it is necessary to take into account grounding system the electrical network through which electricity is supplied to it. Single-phase devices can remain operational when connected to a 220 V power grid, both with grounding and without grounding. The operation of a three-phase leakage protection device is allowed only in networks with a tn-s system, providing a zero working and zero protective conductor.
As a rule, the bulk of the electrical networks of the domestic housing stock operates in the outdated tn-c system, in which there is no PE conductor. The operation of three-phase RCDs in the tn-c system is strictly prohibited. In this case, the PUE permits the use of three-phase devices only if provided house grounding. In order to install this device and protect the wiring of the house from fire, which can occur as a result of current leakage, it is necessary to equip the ground loop, which will ensure the transition to the system tn-c-s.
Finally, we recommend that you familiarize yourself with another 380 V RCD installation diagram in the video, without a neutral wire:
So we examined the possible schemes for connecting a three-phase RCD to the network. As you can see, you can connect a protective device in different ways, it all depends on the conditions of use.
It will be helpful to read:
- How to assemble a 380 V switchboard
- Errors in the installation of electrical wiring
- Reasons for the tripping of the residual current device
Hello! Tell me, is it possible to connect it through HELL 14. whether the electronic difavtomat will also protect. what RCD did you use? Vadim.
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