Today, no one can deny the dependence of modern man on electricity. The comfort of living in houses and apartments can be assessed by the presence in them of a certain amount of household electrical equipment, power tools and various kinds of electrical appliances.
The more of them, the more comfortable the owners in their house feel. But at the same time, the provision of electricity to all of this mass of current consumers is subject to certain requirements, the main of which is human security in his home filled with electrical "assistants".
Comprehensive protection against electric current
Electric current in modern homes is a faithful and inconspicuous helper, but also an invisible and deadly threat. To minimize the possibility of electric shock to a person, various devices and mechanisms have been developed and are widely used.
Their task is to ensure the immediate interruption of the supply of electricity to apartments and houses in the event of a wiring failure, breakdown of electrical appliances, as well as when a short circuit occurs that can cause a fire and further fire. We will consider two devices - RCD and difavtomat as the most common means of protection today.
Which is better and more reliable?
Often before a layman a dilemma arises - an RCD or a difavtomat? What to choose for your apartment or private house? In order to answer this question, you need to firmly understand the difference between the two devices. And this can be done only when the principles of each of them are clearly understood. So, what is the difference between the residual current circuit breaker and the difavtomat?
RCD or difavtomat?
The main purpose of the device is to turn off the supply of electricity to the consumer in the event of a current leak. Everything! The occurrence of current leakage is the only reason this device can work. Therefore, always and without exception, a circuit breaker is used in conjunction with it, which allows breaking the electric circuit at overload currents or short circuits.
In turn, the difavtomat has the ability to respond to leakage currents, overcurrent, short circuit. In other words, a difavtomat is the same residual current circuit breaker, only connected to a circuit breaker and housed in the same housing.
Therefore, the answer to the question "RCD or difavtomat - what to choose?" In itself contains a multivariance embodied in the specific requirements for the protection device and depending on many factors. And, in fact, answering it, you must understand that the residual current circuit breaker is a separate device that cannot be installed without a circuit breaker. And if you chose an RCD, you need to purchase one as well.
RCD - protection and safety
The residual current device is selected according to the technical parameters under which it is created. How to choose an RCD by type? The type of apparatus depends on the tasks assigned to it. They are divided into five types - AC, A, B, S and G. The first is designed to protect against alternating current leakage, and the second from alternating current and from constant pulsating, which is very important if computers, switching power supplies work in the circuit, TVs and power tools. The third type is very rare, as it is used mainly in industry. But the fourth and fifth groups are mainly used in fire alarm circuits.
Devices can be either electromechanical or electronic. The former work stably without an energy source, while the latter is necessary. Therefore, either a built-in power supply is used, or they work from a circuit. But, despite these differences, both are labeled with an indication of the main characteristics.
Important question
How to choose an RCD? To evaluate this or that model of the device, you must be able to navigate in the various numbers and icons printed on the external panel of the device. The first thing you need to pay attention to when choosing a device is the rated current at which the device will work without failures and for a long time.
On the case of the device you can see one of the numbers indicating the amperage, designed specifically for this device and ranging from 6 to 125 amperes. And the leakage current at which this device should operate is indicated in milliamperes and ranges from 6 to 500 mA, depending on operating conditions. Another important parameter of the device is the rated non-breaking current, which is also indicated in milliamperes and is equal to half the leakage current of the device. This parameter shows the consumer the range in which the device can operate.
It is impossible to answer the question of how to choose an RCD without knowledge and the following numbers that mark the devices. An important indicator when choosing a device is the rated voltage for which the device is designed. Modern electric circuits operate on 220 and 380 W, but in the case of using an electronic device, interruptions in its operation are possible due to unstable voltage in the network.
We select and ask
Often you can hear the following question: “How to choose an RCD by power?” Its setting is somewhat incorrect, because this device is not selected by power. It is necessary to be guided by the requirements of the rated voltage of each individual circuit, the rated leakage current, the rated non-disconnecting current, the rated short-circuit current at which the device does not fail, and the rated shutdown time, which can range from 0.3 seconds to 20-30 milliseconds.
A lot of articles have been written on the topic of how to choose the right RCD, but they all come to the same conclusion - the choice of residual current device is purely individual. After all, the state of the external environment, the number and composition of electrical equipment, the state of the wiring in each apartment and each house are not the same.
But the general principles for certain categories of consumers are still developed. And the problem: RCD - which one to choose - boils down to the following: for circuits in which appliances using high humidity (boilers, washing machines and dishwashers) work, devices with a rated breaking current of 10 mA should be used, and for other rooms and appliances limited to a setting of 30 mA.
Using a residual current device
In order not to study the protective shutdown devices in too much detail, it is worth noting only some points related to its use. On the basis of what you can successfully make a choice to any potential consumer, even without special training. Difavtomats and RCDs perform the same functions and provide an appropriate level of security. But the use of RCDs has some differences that can and should be considered when choosing devices.
As already mentioned, devices cannot be installed without automatic devices. Consequently, the question arises of acquiring one and installing not only one, but two devices in the switchboard. With a lack of space in the shield this can be a problem.
When the circuit is de-energized when using the device with an automatic machine, the reason for the shutdown is clear. Knocked out machine - overload or short circuit. The device itself worked - a current leak. You can fix the cause quickly.But in class-average difavtomats (ordinary for everyday use), the cause of its operation cannot be recognized. Therefore, diagnosing a trip is quite difficult.
There is also a difference in device repair. When using an RCD and a circuit breaker in case of breakage, the repair comes down to replacing one of the devices. And this is a saving, because replacing an expensive difavtomat is much more expensive than a cheaper circuit breaker or the device itself.
So, how to choose an RCD based on the information received?
The residual current device is selected for specific electrical circuits. Immediately you need to make a reservation that the RCD is not a competitor to the difavtomat. For ordinary apartments with old and dilapidated wiring, installing a device with a machine will not be the best option. Because they, like difavtomats, can often falsely work in such conditions. If there is no space in the switchboard for installing two devices, the best way out is to install a difavtomat, although this is more expensive.
Each task has its own RCD
The question of how to choose an RCD for an apartment worries many citizens. If there is enough space in the switchboard, you can install the device and the machine according to the following recommendation.
The machine is bought at 16 A, which means that the device is purchased at about 25 A. If the apartment is small, then one type A device for 30 mA is enough.
But if the apartment is large enough or the wiring is old, it is advisable to install the device on each group of devices.
For example, a bath-kitchen group, utility group, residential and leisure group. So you can avoid a complete blackout of the apartment. Or place it on each outlet.
How to choose an RCD for the house? The selection of the device in this case is no different from the one described above, only taking into account the fact that a personal home, as a rule, also has many outdoor current consumers. Therefore, installing the device in groups in this case is most acceptable. And for this you have to turn to the paragraph, which talked about the types of devices. In your home when installing equipment in groups and if you have the funds, of course, a type A device is desirable, which provides normal protection for the computer, electrical appliances and TV. And the type of speaker can be used for other groups.
RCD which company to choose? This question is being asked by many, but in reality there is only one answer to it - branded firms produce quality products. And the use of in-house RCD, as it were, of branded production in many cases will help to avoid many problems, the smallest of which will be false positives.
Make the right choice!
RCD or difavtomat? What to choose? In the end, it should be clear that many factors influence the choice of protection device. And clearly it is simply impossible to answer. Therefore, only general information is provided here to help you learn about the residual current device. But advice on the general principles of choosing protection devices remains valid.