More and more people are thinking about the need to protect the home electrical network from possible leaks, overloads and short circuits. Protective equipment most often has a considerable cost, but the negative impact of these factors leads to even more unpleasant consequences in the form of expensive repairs or the need for a complete replacement of household appliances. To choose the right equipment, you need to know how it works, as well as what is the difference between RCDs from difavtomat.
Functional purpose
The RCD works if the difference between the currents in the neutral and phase wires is recorded in the network connected to it, since this indicates a leak. This situation is fraught with serious consequences, the most dangerous of which is a person getting an electric shock if he touches damaged equipment.
However, if you immediately turn on all the electrical appliances that are in the room and form a serious overload, the RCD will not work. Wiring in the absence of any other security options will burn with this device.
With the help of an RCD, it will not be possible to ensure the safety of the power grid from the possible occurrence of a short circuit or excessive load in it. By installing such equipment in your network, you cannot achieve protection against any emergency situations.
The differential machine is a special device that combines the functions of an RCD and a circuit breaker. Installation of a difavtomat in a house ensures guaranteed power supply safety.
The difference between the difavtomat and RCD is that the first provides full protection against leaks, short circuits and increased loads, which cannot be achieved with the help of RCD.
There are several other circumstances that it is important to pay attention to when choosing a device. This primarily concerns the availability of free space on the DIN rail of the electrical panel. RCD, regardless of which particular model in question, should have its own protection against short circuit or overload. In addition to it, a special circuit breaker will have to be equipped, and the UZO-automatic combination requires a large amount of free space. If there is no free space for installing all this equipment on the panel, the question of choice disappears by itself.
If the main task is to provide protection from any troubles of large household appliances such as a washing machine or boiler, it will be quite enough to equip the mains with a simple differential machine. The main thing in this situation is to choose the right model, the technical characteristics of which will correspond to the existing load.
If it is necessary to provide protection against damage to the entire wiring line, which will include every socket, lamp and all other equipment connected to the mains, it will be possible to install an RCD and a circuit breaker. Often, such a combination is used as the most rational solution. If the load on the power supply network increases over time, the differential machine will constantly turn off the power to the room under the influence of overload, and it will need to be replaced in order to count on a higher rated current.When using an RCD, just change the circuit breaker.
The financial issue should be taken into account. If the protection of a separate section of the wiring, which will be provided using an RCD and a circuit breaker, fails for one reason or another, only one device will need to be changed. If a differential automaton breaks down, it must be completely replaced, and this will come out an order of magnitude more expensive.
If the RCD is broken for some reason, the power supply in the house or apartment can be restored if necessary by placing a special jumper between the load and the switch. In the event of similar problems with differential machines, power recovery will have to be carried out only using a backup machine.
Why devices turn off
Differential machine and RCD can be turned off in different ways. The RCD will turn off when a current leak has been detected in the mains. If the machine that protects the RCD is switched off, this indicates a short circuit or excessive load. If the differential machine is disconnected, the cause can be determined using a specialized mechanical indicator, which is equipped with most of these devices. The indicator only works if a leak occurs.
Differences in appearance
The RCD itself and the differential machine themselves have a similar appearance in size and shape. In this regard, it is better to purchase a device with the support of an experienced electrician. However, it is useful to know the basic subtleties of choosing such devices.
First, pay attention to the current marking. If only the designation of the current strength is present on the device’s case, this is an RCD. If there is also a Latin letter, this is a differential automaton. Quite often, modern manufacturers prefer to write the full name on the case immediately, but this approach is not always found.
If the protective device is manufactured in Russia, a VD (differential switch) is prescribed in front of the digital designations. In this regard, problems with the choice most often appear when you want to buy equipment from foreign companies.
Important subtleties
One RCD can be connected to a group of several machines as one of the options for providing cost-effective protection.
Modern RCDs can have a different threshold for operation. If we talk about the protection of equipment that is connected, for example, to a water supply or gas pipeline, you should pay attention to the device, which indicates a trip current of 0.01 A. For all others, you can use an RCD, in which there will be a trip current of 0.03 A.
Installation of circuit breakers
For comprehensive protection, together with the RCD, an additional circuit breaker must be installed. It is a special device with which a current of the required strength is carried out in the normal state of the circuit when there is no excessive load in the mains.
If a short circuit or excessive load is detected during operation of the equipment, the circuit breaker completely de-energizes the network, but it does not work like standard automatic plugs or fuses that are designed for an increased number of tripping cycles.
On the market you can also find a large number of models that work when other disturbances occur in the network (for example, a sharp drop in voltage).
Such equipment is installed inside electrical panels or cabinets, where it is fixed to special DIN rails.
