Socket with built-in RCD: device, connection diagram, recommendations for selection and installation

Residual current devices have recently come into widespread use due to the increased number of household appliances.But residents do not always want to connect the entire apartment to this equipment due to possible false alarms.

That is why a regular socket with an RCD is popular, into which you can connect only one potentially dangerous device: a washing machine, a shower stall, a dishwasher. You will learn everything about the principle of operation, design features and types of protection devices from our article. Here you will find valuable installation tips.

Relevance of electrical sockets with RCD

More than 40% of fires occur due to faulty electrical wiring, and thousands of people a year die at home from electric shock. These unfortunate incidents might not have happened if the electrical circuit had been under control RCD - residual current device.

This device monitors the difference between the zero and phase currents, and if there is a significant difference, it turns off the power supply to the load.

The current threshold for human muscles not to let go of the wire is 10 mA, so the socket with an RCD must ensure a clear determination of its level and triggering of the protection.The automation of the device is designed in such a way that when touching a bare live wire, a person does not even have time to feel the electric shock - the device turns off the power supply almost instantly.

When installing an RCD in a house, you need to be sure that there are no current leaks inside the walls, otherwise the device simply will not turn on.

A breakdown of faulty wiring inside walls can be invisible for a long time and not lead to a fire hazard. But over time, the wire insulation becomes thinner and the current increases, which can cause a fire. The RCD detects the problem long before the cable heats up and disconnects it from the network.

If there is a hidden breakdown of insulation inside the walls, the user’s wallet also suffers. After all, in fact, electricity is spent on heating concrete slabs and plaster. That's why RCD installation is an excellent way to increase the electrical safety of housing and its residents, as well as prevent unnecessary costs for paying for electricity.

Internal diagram of the device

The residual current device is based on a differential transformer, which is a toroidal core with windings. It is he who is responsible for determining the leakage current, the occurrence of which leads to the operation of the electromagnetic relay.

The active load should be turned off within a maximum of 30 ms, although there are models that are designed for a threshold value of 10 ms.

For domestic purposes, sockets with an electromechanical RCD are produced, which does not require additional power to operate.

The RCD device for the socket has a special design that allows all equipment to fit into standard socket box. Miniaturization of components also affects the cost: if you purchase the components of the device separately, their price will be at least three times lower.

Possible design options

In the combination of a socket and an RCD, both devices are equivalent. It is difficult to determine the main role of any of them. Therefore, externally they can look like a socket with an RCD or an RCD with a socket.

The protective adapter is attractive due to its low price and ease of use. It can always be moved to another room to connect the desired device

The design of these devices can be as follows:

• module built into a socket box;
• monoblock adapter inserted into a simple socket;
• module mounted on a DIN rail.

In fact, these devices are two independent devices connected within one design. Their functionality is the same, so the main selection criterion is the convenience of one or another model in a particular situation.

Connection diagrams for sockets with RCDs

Methods for connecting sockets with built-in RCDs may be different. They depend on the number of connected devices, the location of the wires and the presence of a ground bus. It is important to connect the outlets in the house in such a way as to ensure maximum safety for residents and comply with all electrical standards.

Single outlet with grounding

The simplest scheme for installing an RCD socket into a home electrical network includes only one device. Not only the phase and neutral, but also the ground wire fits to it. This scheme allows for double protection of a person.

The circuit with a single socket is the simplest and cheapest. If necessary, you can connect any household appliances to it via an extension cord.

Grounding serves as a passive way to protect a person from electric shock when coming into contact with a live household appliance. In this case, the main flow of electrons goes into the ground, but the person is still in danger. And the protective shutdown device eliminates almost all health risks in the situation described above.

The main advantage grounded circuits is the ability for the current to flow smoothly into the ground, which will lead to instantaneous operation of the RCD. In the absence of such a leak, the conductor will be the person who comes into contact with the live surface. This may result in a severe electric shock.

Socket connection system via difavtomat

The two-level system of RCD and difavtomat is optimal from the point of view of convenience. General differential machine provides additional protection for the entire apartment not only from leakage current, but also from network overloads and short circuits. This scheme is recommended for use in residential premises with highly branched wiring.

It is advisable to install an additional RCD in the form of a socket in case of frequent power outages when a general apartment circuit breaker is triggered due to one household device

When the electrical mechanism of the socket is triggered, it will turn off without de-energizing the entire apartment, while the remaining rooms will remain under backup protection.

A difavtomat may have the same threshold current as a socket with an RCD, or maybe more (100 mA). If its value is the same, both devices connected in series can simultaneously knock out. The advantages of connecting the socket to ground remain the same as in the previous scheme without a difavtomat.

Single level multiple socket system

When several sockets with RCDs are connected to the network, the principle of their operation does not change. Each device ensures the safety of using household appliances connected to it.

Sockets with RCDs certainly increase the safety of using household appliances, but from a financial point of view such a scheme is impractical

This circuit is installed quite simply and does not require installation of a general difavtomat or RCD. The advantages of connecting grounding remain the same as in the previous options considered.

Differences in operating principles RCD and differential circuit breaker are given in the article, the contents of which we recommend that you familiarize yourself with.

The only disadvantage of a system of several outlets is their cost, because you will have to pay a considerable price for each device. An alternative to this option is to install one RCD for the entire room.

Not recommended circuit without grounding

The schematic diagram for connecting sockets with an RCD in the absence of grounding is almost no different from the two-level and single-level options proposed above. The only difference is the absence of a wire, which ensures that current is drawn from the body of the household appliance if its electrical insulation is damaged.

The connection diagram for a socket with an RCD without grounding can be used both in the presence of a common circuit breaker and in its absence

In fact, the vast majority of houses and high-rise buildings were not equipped with grounding until 2000, so this connection scheme is the most common. However, there is a hidden danger in it - the lack of contact between the body of the household appliance and the “ground”.

This fact is not only a problem for human health, but also has a negative impact on the performance of microcircuits in household appliances. Therefore, the presence of a ground bus in home electrical wiring is extremely necessary and desirable.

Characteristics of sockets with RCD

Modern sockets with RCDs are not installed in every apartment. The reason for this is the predominant installation of these devices or automatic devices at the common entrance of wires into the living space.

To decide on the best option for arranging electrical protection at home, you need to familiarize yourself in detail with the pros and cons of sockets with RCDs.

Advantages of combined devices

2-in-1 current leakage protection devices are not often used, but they have a number of advantages that make them indispensable in a number of cases.

The threshold differential current is always indicated on the front panel of the socket, therefore it is a key characteristic that determines its electrical safety function

The advantages of sockets with RCD include such qualities as:

• guaranteed blocking of electric shock in the presence of its leakage;
• no need for additional wiring or purchase of an expensive general high-power difavtomat;
• versatility in networks with different voltages;
• the ability to plug in any household appliance with a power of up to 3 kW;
• performance monitoring using a special testing button;
• possibility of operation at leakage currents of 10 mA;
• protection in case of damage to the neutral wire;
• ease of installation;
• compactness;
• presence of a voltage indicator in a visible place.

The listed advantages of sockets with RCDs make them indispensable if you want to quickly provide additional protection against leakage current. In addition, these devices are quite mobile and can always be moved to another location within a few minutes.

Disadvantages of combining a socket and an RCD

There are not many sockets with RCDs and similar portable devices for sale. The reason for this is a number of their shortcomings, which force consumers to choose other devices.

With the same functionality, the cost of sockets with RCDs from different brands can differ tens of times, although the reliability of these devices is approximately the same

The disadvantages of protective sockets include:

1. High cost. It is much easier to install one RCD for an entire apartment or a group of rooms than to install a separate device in each socket.
2. Availability of competitive devices in the form of automatic devices, which also provide additional protection in the event of network overload or wire short circuit.
3. Frequent false alarms, especially in old houses with damaged wire insulation.
4. Many models require deep socket boxes, which complicates their installation.

Thus, sockets with RCDs are a rather highly specialized product. It is used only when there is no desire or opportunity to install common circuit breakers in an apartment, or there is a need for protection with a threshold level of 10 mA.

Rules for connecting to the network

Connecting a built-in socket with an RCD to the network is quite simple.

The maximum list of actions for this may look like this:

1. Select a socket box of the appropriate size for the device.
2. Drill a hole in the wall with a crown and connect phase, neutral and grounding (if available) to it.
3. Turn off the power.
4. Connect the electrical wires to the appropriate terminals on the outlet.
5. Secure the device in the socket.
6. Turn on the electricity.
7. Click the “Test” button and check the functionality of the device. Normally, the power supply should be turned off immediately.

Installation of the device in the form of a monoblock adapter is not required at all. It is inserted into a simple socket, and on the other side household appliances are connected to it.

To install a socket with an RCD on a DIN strip, you simply need to secure it, connect the corresponding wires to the terminals and test. After this, the device is ready for use.

Tips for choosing the right model

Choosing a suitable socket with an RCD is not difficult, because manufacturers offer mostly standard solutions, and the model range of these devices is small.

Leakage currents that can lead to fire are much higher than those that can kill a person. Therefore, household sockets with RCDs provide complete fire safety in case of insulation breakdown

When purchasing, you should pay special attention to the following nuances:

1. For bathrooms, the degree of protection must be at least IP44, and for dry rooms - IP21 or IP22.
2. For modern household appliances, you can take devices with a differential shutdown current level of 10 mA, and when connecting older devices - 30 mA.
3. If you plan to connect long wires or several household appliances to the outlet, it is recommended to use models with a leakage current of at least 30 mA.
4. The maximum power of the connected equipment should not be higher than that indicated on the outlet. It is recommended that the permissible current be 30-50% higher than the actual operating current.
5. The statistics of defects and false positives are almost the same for most well-known brands, so it’s not worth overpaying for the name.
6. Each device, unlike simple sockets, must have a technical passport or operating instructions indicating technical parameters.

If you purchase a socket adapter, you can check its functionality right in the store. It is enough to turn on its power supply and press the “Test” button, which simulates a current leak.

After purchase, you need to keep the receipt so that if a defect is detected, you can exchange the device.

Conclusions and useful video on the topic

Operating principle and device of the RCD:

Demonstration of the operation of a socket adapter with an RCD:

The best option for electrical protection of residential premises is, of course, the installation of a two-level system of automatic circuit breakers. However, such a scheme requires serious installation work and financial costs.

A compromise option, if it is necessary to protect individual household appliances, is to purchase an outlet with a built-in RCD. This device will help to detect an electric shock in time, turn off the power and save a person’s life.

Tell us about how you installed an outlet with a built-in protection device with your own hands. Share only you know technological nuances that will be useful to site visitors. Please leave comments, post photos, ask questions in the block below.