How to connect the rcd

If your apartment has a large number of household appliances, then you should install a device such as a RCD. Otherwise, all appliances will be under great threat. In the article we will look at how to connect such a device and automatic in the apartment and private house, we will demonstrate the diagrams, photo and video instructions.

Why do you need

Installation of such devices is necessary for several reasons. Mainly, it was designed for protection. From what? First, the RCD protects people from electric shock, especially in cases when there are faults in the electrical installation. Secondly, the device is triggered and disconnects the current due to accidental or erroneous contact with the conductive parts of the electrical installation, in case of a current leakage. And, thirdly, ignition of an electrical wiring in case of short circuit is prevented. As can be seen from the above, this machine actually performs an important function.

Today it is possible to meet differential automatic machines which feature consists in association of the automatic switch and UZO. Their advantage is that they take up less space in the panel. In all cases when connecting all contact connections should be brought to it not from below, but only from above. One of the reasons is more aesthetic. But there is a much more weighty reason. The fact is that the RCD is able to reduce the efficiency of the work of all household items. Moreover, during repair work, the electrician will not get confused, and he will not have to learn complex, intricate schemes. So, now it's time to consider connection options.

Connection methods

There are four connection options:

1. Bipolar connection to a single-phase network.
2. Connection of a four-pole to a three-phase network using a neutral.
3. Connection of a four-pole to a three-phase network without the use of neutral.
4. Connecting a four-pole single-phase network.

Consider each case separately.

Connection of a bipolar RCD to a single-phase network

Among all the listed connection methods, this is perhaps the most common scheme. When it is connected there are no complex turns. Moreover, such a device can be connected independently. To do this, on the case or in the passport it is necessary to find out exactly where the neutral or zero is located on the machine, as well as the phase. As a rule, such signs 1,2 and N. are indicated on the automaton. 1 - implies incoming phase conductor, 2 - outgoing phase conductor and N denotes zero or neutral.

One of the main conditions for the connection of such an RCD is that it is installed in all cases after the circuit breaker! This requirement allows you to protect the electricity meter from increasing current.

There were cases when the device failed. Why? The thing is that a current has passed through it that exceeds its rated operating current. To prevent this from happening in your case, buy a device with as much as possible with a large rated operating current. Moreover, when connecting it is important to observe the correct sequence. Otherwise, problems may arise during its operation. For example, if at connection to connect the zero terminals with the phase, then the device will immediately fail.

Connection of a four-pole RCD to a three-phase network using a neutral

This connection method is also quite common. The principle of its connection is practically no different from a single-phase network. Only in this case is mounted a four-pole RCD. It has four incoming wires, which are labeled A, B, C and zero (N) on the machine. As a rule, the connection scheme is indicated on the body of the machine. The only difference may be that on a quadrupole device, zero can be on the other side. Most importantly, connect the outputs and inputs correctly.

These RCDs are used to protect against electrical wiring fires at high leakage currents. If it is used for protection against electric shock, it is recommended to use a leak point that is 10 to 30 mA.

For the very protection of the device, an automatic switch is mounted directly in front of it.

It is best to connect single-phase networks through a zero busbar, which is mounted directly on the DIN rail in the shield.

Also when connecting it is extremely important to observe the color marking of the wire, as well as the connection of the neutral and phase conductors.

Connection of a four-pole RCD to a three-phase network without the use of neutral

This scheme is used in most cases to connect three-phase electric motors. The machine will disconnect it from the network as soon as a small short circuit of the windings occurs. To connect a three-phase motor, three phases of supply voltage are required, namely A, B and C. A protective conductor PE is also required, which will serve as the housing grounding. As a result, there is no point in acquiring a five core wire, but four wires will suffice.

Connection of a four-pole RCD in a single-phase network

This use can be called irrational and expedient. However, in some cases this is the only right decision. For example, if in the future you plan to expand electrical wiring, transferring it to a three-phase network or adding several single-phase networks. Moreover, such a scheme is used in cases of temporary use of emergency replacement of a faulty bipolar RCD. Connection is quite simple. For this, the zero and phase is connected to the corresponding terminal. In this case, the connection of the phase conductor to the terminal is made only if the “Test” button is currently connected. Such a terminal is located near the zero.

Connection in the apartment and in a private house

Connection diagram in the apartment is performed only on a single phase network. For this reason, the connection is made in the following order:

1. Introductory automat.
2. Electric meter.
3. WHO 30 mA.
4. Electrical wiring in the apartment.

If you have power consumers in your apartment, for example, a washing machine or an electric oven, then it is recommended to connect the protective RCD device additionally.

With regard to the connection of the machine in a private house, the connection sequence is as follows:

1. Introductory automat.
2. Electric meter.
3. Automatic from 100 to 300 mA, the choice is made depending on the amount of current consumed by all household appliances.
4. Automatic machine for individual current consumption. Typically, 10 to 30 mA is used.

So, we have examined with you some of the features and differences of the connection of an RCD in certain circumstances. Most importantly, remember that if you do not have any idea about this system, then it is better not to experiment.

Video

A few words about typical errors when connecting an RCD:

Scheme

In order to properly install the RCD, we invite you to familiarize yourself with some diagrams of its connection: