Homeliness, Tools and equipment
Differential or RCD. RCD device. Connecting a Difa Automaton
A home electrician is a fairly complex and diverse topic, and it is desirable to know the basic details for every homeowner, since not only money costs but also the security of your home depend on it. In this article, we will try to find out what is better - the Difa Automaton or RCD.
Introduction to the topic, or what is a diffuser?
The device, called a differential automaton, successfully combines the functions of both the RCD and the conventional circuit breaker. This machine protects a person in case of touching bare sections of the conductive part of the wire or those parts of electrical networks that are under stress due to damage to the wiring or other similar factors. To date, there is a huge number of such devices that are designed for different operating currents, and for different leakage currents.
Its main distinguishing feature is that it consists of two well-separated functional parts: a circuit breaker (for two or four poles), as well as a module for protection against electric shock. The installation of the diafi-automat should be carried out exclusively on the mounting DIN-rail, and this design takes far less space than the combination of the RCD and the circuit-breaker.
Considering the time of operation, which is only 0.04 seconds, differential automata provide the most adequate protection against human injury by electricity in practically any operating conditions. It is also important that the differential automatic device protects the devices in the network qualitatively from overloads, which inevitably arise for various kinds of emergency situations. And further. Its design provides the fastest power outage in conditions where voltages exceeding 250 V are observed in any part of the network.
Given the unenviable characteristics of domestic electrical networks, as well as the degree of their deterioration, the latter characteristic is especially important.
Main Advantages of the Difavomat
• Very fast response speed.
• Protection of equipment against power surges and overloads.
• Ability to operate in conditions from -25 to +50 degrees Celsius.
• Huge wear resistance threshold.
What is an RCD?
This abbreviation stands for "protective shutdown devices". Triggering is performed when recording the presence of leakage currents. Simply put, how much current came to the device by one wire, the same number should go to another section of the wiring. If the current starts to go to the ground or the ground wire, the protection instantly operates, immediately disconnecting the network from the power source.
Such a system must (!) Be placed on the outlet groups, as well as on boilers, washing machines and electric cookers. Such devices do not protect (!) Your equipment and wiring from system overloads or short circuits.
The latter circumstance is often not taken into account by electricians who, for the sake of reducing the cost of the scheme, often use only one RCD. In addition, there is also a vested interest, when it is issued for a differential automaton, the value of which is higher.
Basic information about the RCD device
What is the very principle of the RCD? Its work is based on the response of the current sensor to the change in the differential value of the current in the conductors.
What is a current sensor? This is the most common transformer, but made in the type of a toroidal core. The pickup threshold is set with a magnetoelectric relay, which has an extremely high sensitivity.
It is important to note that all RCDs made in this classic scheme are extremely reliable and simple apparatuses that have very high reliability and reliability.
What are the details of the actuator?
- From the direct contact group, set to the maximum value of the current.
- Springs, which directly opens the circuit, if in its work there are some malfunctions.
If you want to check the device yourself for work, just press the "Test" button. In this case, the current is artificially fed to the secondary winding, and the relay is triggered (should, in any case). So if necessary, you can easily and without any costs be able to check the serviceability of all your equipment.
Principle of operation of the RCD
If we talk about the nominal operating mode, then the current (I1 = I2) flows in the counter-parallel direction, inducing magnetic currents in the secondary winding of the transformer (Ф1 = Ф2). They have exactly the same value, due to which they mutually compensate each other. Since the current in the secondary winding in this case is practically zero, the relay can not operate.
RCD operation with leakage
When in contact with conductive parts, a leakage current occurs. In this case, the current I1 is not equal to I2, and therefore a secondary current appears in the secondary winding, the value of which is sufficient to trigger the protective relay. It provokes a spring switch, the RCD is switched off.
Differences between the two protection systems
To continue our narration further, we also have to find out what is the difference between the RCD and the Difa Automaton. It can not be said that the differences are so drastic, but they are still there.
It should be noted that the coverage of this issue is extremely important, since it is sometimes impossible for even some electricians to distinguish these devices from each other. However, there is nothing to be surprised at: they are very similar even to photographs.
The main difference between the dif-automat and the RCD is that they are intended for several different purposes. We have already mentioned this above, but we will repeat this once more: the RCDs can not be used to protect equipment and wiring from overload or short circuit! Moreover, before the RCD it is necessary to mount an automatic switch that will save the device itself from this kind of trouble. This is the difference between the RCD and the Difa Automaton.
Be sure to consider this when buying or consulting with specially "thought out" electricians who will happily save on your own equipment.
Let us recall once again that a differential automaton can be used as a fuse in those houses where there is a constant danger of chronic overloads in the network.
This is the detailed difference of the RCD from the dif-automaton. But how to make the right choice in the store? After all, we have already said that these devices are extremely similar among themselves even in photographs.
We buy correctly!
First, pay attention to the direct name of the device itself. Today, almost all manufacturers have finally come to meet consumers, willing to indicate on the body of the device itself information on whether the diafault or RCD in front of you. Therefore, we would not recommend buying such a technique of Chinese production. Persistent Asians either do not say anything at all, or they do it using only understandable notation.
Approximately to the same category is the advice on careful familiarization with the marking, which should always be indicated on the same case of the device or on its packaging (a less reliable option).
So, if you see only the rated current on the case (16, for example), and the letters before this designation are not present, then you hold the RCD in your hands. Note that "16" in this case means "ampere". If there are letters B, C or D in front of the numbers, then you have a difa-automat in hands. Letters designate typical characteristics of thermal and electromagnetic releases, but on a household level, paying special attention to them is not necessary.
In addition, it does not hurt to also look at the connection diagram. This method is somewhat more complicated, but it gives a 100% guarantee of differentiation. This information should also be displayed on the enclosure. So, if the scheme indicates only the presence of a dif-automaton with the designation "Test", then before you is the RCD (do not confuse!). Accordingly, if there is a "Test" and the windings of the releases are indicated, then you hold a differential automaton in your hands.
However, it is important to warn you that the last item is not being seriously addressed, since at the present time there are a lot of absolutely identical devices in size.
We pass to the main
So, the Difa Automaton or the RCD? What is the conclusion based on the above? What is better to choose, which is more reliable and suitable for operation in domestic realities? To answer this question, we will compare the devices at once for six indicators. Comparing all the pros and cons, we will try to reach a consensus.
The volume occupied by the device in the shield
Of course, in this aspect, only those people who have very little space in the apartment can see any significant differences, which makes it impossible to mark a normal electric shield in the hallway. However, given the universal desire for compactness and beauty, such in our country the majority. In addition, it is better to place everything in as small a space as possible, since later the shield will not have to be expanded if there is a need to install more powerful electrical equipment in the apartment.
So, at present, the RCD (three-phase - including) occupies much more space in the shield, rather than a differential automaton. What is the reason for this? The most attentive readers could already find the answer to this question in the article.
Thus, in this "round" defeated the machine, allowing to leave space for the expansion of the design.
Easy installation
As in other cases, for many electricians the speed and simplicity of mounting the entire structure is important. If you are interested in setting the RCD, the phase is led to the switch, and from its output a jumper is mounted to the input of the tripping device. Zero is also connected to the input. It should be noted that there are several connection schemes at once, which are studied by professional electricians. As a rule, they are not needed in everyday life.
How to mount a differential automaton?
And what about the connection of the diffuser? If we talk about a differential automaton, then the phase and zero immediately clings to the input terminals of the device, so that in the general scheme it turns out how much less jumper and transition. Accordingly, the internal structure of the flaps is also greatly simplified.
Thus, the connection of the diffuser is much easier and faster, so in this case, we are sure that we are the winner.
Benefits of operation
Theoretically, we can assume that once on the line of outlets in the bathroom, the RCD worked. You can immediately assume that somewhere on the line there was a leakage current. Of course, the algorithm for troubleshooting is somewhat more complicated, but the main conclusions can be made immediately.
If the circuit-breaker is disconnected, then the reason is quite obvious: overload or short circuit. You have only to find out the reason and eliminate it. Given that the reason for switching off the machine is more or less clear, it will not be so difficult to do it.
And now let's look at all the same, but with reference to a differential automaton. Here when you turn it off, the cause is immediately unclear, so you'll have to check all known causes. Accordingly, the time for this will go much more. This is how the RCD differs from the Difa Automaton in this respect.
Thus, at this stage we would prefer RCD.
Question of value
Since today there are a lot of the most diverse manufacturers on the market, we will consider the cost of EKF products, which is quite popular among professional electricians. So, the standard EKF-DIA-automat on 16 A costs about 600 rubles, the RCD for the same current strength is the same 600 rubles, and the shutdown machine is sold at a cost of about 40 rubles. Acquiring all the same on specialized sites, you can at all rely on the shutdown machines, which in such cases are sold almost on weight.
Before connecting the diafavtomat, you should make sure that there are no frequent and abrupt voltage drops. Why are we talking about this? This will become clear after considering the specifics of replacing this equipment.
Given the fluctuations in value depending on the supplier, it is difficult to talk about the advantages of this or that option.
Service life and replacement cost
As can be assumed, the characteristics of this criterion automatically follow from the previous one. Everyone knows that any electrical equipment has a certain lifetime, after which it becomes unsafe to operate it. Let's assume that, for whatever reason, a RCD or an automatic shutdown device has failed. What to do next? To change the failed part, after which the system will continue to work in the previous mode.
But the situation with the diffuser is not so straightforward. Suppose that the winding of any of the releases has failed, while the built-in RCD on testing has shown its full performance. Alas, but it does not matter, since in any case you will have to replace the entire Difa Automaton, the price of which makes this event extremely unprofitable. It's much easier to replace a penny automatic, which often fails.
Thus, in this round, the victory is again over the RCD.
Among specialists, it is widely believed that devices that combine several functions at once are less reliable than automatic machines that are designed for only one thing. So the RCD or the Difavo Automaton? What to choose to ensure the highest reliability?
You can argue about this for a long time, but the practice has unambiguously shown that in practice the percentage of refusals is almost the same. It is possible that this parameter depends solely on the manufacturer. So in this case it is extremely difficult to draw a conclusion about the unequivocal advantage of this or that device.
One can only say that the RCD, the connection scheme of which we reviewed above, assumes greater reliability in conditions of domestic voltage drops. Naturally, if you do not forget to connect the circuit breaker before it, as we have repeatedly mentioned above.
Thus, in most cases it is the RCD that will be the best choice. However, it all depends on the characteristics of your network, as well as the size of the electrical panel.
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