What is better difavtomat or RCD: characteristics of devices, the main differences between them

Safe working and living conditions for each person presuppose the provision of reliable protection against electric shock. A serious hazard comes from lines with damaged or poor quality insulation. Life-threatening voltages are present on household electrical appliances with metal enclosures. Protection is provided through the installation of special devices. It is worth understanding in more detail which of them is better, a difavtomat or an RCD.

The need to use protective devices

Electromechanical and electronic devices ensure proper human safety, protect power lines from accidental short circuits and overloads. For this purpose, it is customary to install difavtomats or RCDs (VD):

1. The residual current device (differential switch) provides fast-acting protection by reacting with a phase-to-earth fault, the case against human touch. Such a device is used independently, is included in the system with neutral or grounding.
   instagram viewer
2. As for the difavtomat, it is represented by a switching contact device. Its main purpose is to conduct, disconnect / enable, electrical currents in normal operating conditions. If the differential current reaches the indicated limits, the contacts open. Structurally, this device is represented by 2 or 4 circuit breakers, a block for differential protection.

The principle of operation of the difavtomat is that it will de-energize the circuit when water is applied to the appliance. Similar protection will appear in the event of damage to the insulating part of the cable. In parallel with such a device or instead of it, RCDs are often installed.

Functional purpose

When considering the described devices, an ordinary person cannot always understand how diff differs from ouzo. In terms of external equipment, they are very similar, but radically differ in terms of their functions.

The residual current device is triggered ifwhen a leakage current (differential) is detected in the mains connected to it. In such a situation, there is a high probability of injury to a person who comes into contact with damaged equipment. Moreover, current leakage entails heating of the insulation in the electrical wiring, its subsequent fire. Therefore, an RCD is necessary to prevent electric shock, prevent overheating and ignition of wires.

If we consider a differential automaton, it is a universal device that combines the RCD described above and an automatic switch (in the common people - an automaton). This device is designed to prevent short circuits in the wiring, prevent current leaks, overloads in the circuit, which often occur in everyday life, at work.

Understanding what is the difference between difavtomats and ouzo, it is necessary to understand that an RCD is not capable, according to the principle of a difavtomat, to prevent a short circuit and loads applied to the network. This is the main mistake of many users, who mistakenly equate the described devices for their functional purpose. The residual current device is an indicator that determines the leakage of current that does not reach light bulbs and household appliances. It reacts to insulation damage and disconnects the working network.

If you intentionally create an overload by turning on many electrical appliances at the same time, the RCD will not work, and in the absence of other protective devices, there is a high probability of fire in the wiring along with this very device. The residual current device does not react in case of a strong short circuit. That is why experts recommend connecting the RCD in parallel with the machine. Such installations work perfectly in pairs, preventing the occurrence of short circuits, overloads and leaks. If you install only a difavtomat, it will provide the necessary protection against the emergency situations described above.

Visual differences

If we compare the machine and the standard RCD in terms of external equipment, the signs that are similar between them immediately catch the eye. Almost identical cases, the presence of a "test" button, a special switch, incomprehensible letter abbreviations and schemes. But if you take a closer look, it turns out that the letter designations are not repeated, and the tumblers and circuits are different, due to their functional characteristics.

It will be easier to understand how ouzo differs from a differential automaton if we examine them in more detail. There is a whole list of visual differences that will help even an inexperienced person distinguish these devices from each other.

Separation by marking

The correct and proven method of visually distinguishing the described units is marking by rated current. On the case of each device, technical characteristics are necessarily displayed, in particular, these are leakage current and operating current. If there are only numbers on the body base, it can be argued that this is an RCD, for example, VD-63. It has a digital designation 16 (A).

If there is a Latin letter B, C, D before such a designation, it indicates the presence of a differential automaton. An example will be a device of the AVDT32 brand, in which the value of the rated current is preceded by the letter "C". It defines the type of thermal and electromagnetic release.

The meaning of electrical circuits

Any protective or executive device is complemented by a schematic diagram applied to the body. On a difavtomat and an RCD, they are very similar, but there are also differences:

1. The residual current device has the main difference in the form of an oval. This sign is usually used to designate a differential transformer, which acts as the heart of the entire unit and reacts to current leakage. Also in the image there is an electromechanical relay designed to open and close a circuit, power contacts for connecting wires.
2. The schematic display of the difavtomat, in addition to the above conventional signs, contains conventional determining the electromagnetic and thermal release that reacts to short circuits and overload current.

Important! Using the shown connection diagram, you can accurately determine the available device.

Title and abbreviated inscription

It is difficult for ordinary people to remember the distinctive features of protective devices connected to the mains. To simplify the task, manufacturers have gone further, they leave its direct name on the side of the product body. So, on the outer box of the RCD, the inscription "differential switch" is displayed.

As for the difavtomat, the inscription on it reads "automatic differential current switch". Practice shows that such identification clues are present in most cases on domestically produced devices, but not on all.. Abbreviated inscriptions are indicated in the following way:

• difavtomat - AVDT;
• RCD - VD.

Qualitative indicators

If we consider the price parameter, the described protective devices differ significantly in it, especially when it comes to imported products. A standard difavtomat is an order of magnitude cheaper in comparison with an RCD that comes with a standard machine.

In terms of quality, imported products occupy leading positions. As for Russian-made devices, they are somewhat inferior to foreign counterparts in such parameters:

• reliability of individual mechanical parts;
• response time;
• reliability and durability of the housings.

Important! If we compare the reliability of the operation of the difavtomat and the RCD, they are practically not inferior to each other.

RCBO is a combined device. The disadvantage during the period of its operation is that when it is triggered, it is difficult to determine the exact reason for the shutdown - current leakage, short circuit or overload of the power grid. However, some advanced models have residual current indicators. An important advantage of RCBOs lies in the ease of installation. It is important to make a couple of screws less than the prescribed amount in a cramped mounting box, thereby increasing the reliability of the chain. If the described unit breaks down, it will have to be completely replaced.

If the RCD is operated in parallel with the machine, the repair procedure is less costly, one of the working elements must be replaced. Such a moment should be taken into account during the design and installation of electrical wiring in the room; you should not discount the possible frequency of overloads and possible short circuits.

Having decided on how the ouzo differs from the difavtomat, it is worth figuring out which apartment wiring schemes are better to use. For a standard apartment, an RCD + an automatic machine or an RCBO will be appropriate. When it comes to a large-scale residential building, it is recommended to connect lines with heavy loads to the difavtomat, for example, a utility block, a boiler room, etc. Groups of outlets, lighting lines work perfectly on a pair of RCDs with an automatic device.