5 ways to test the performance of the difavtomat

Checking circuit breaker functions

In production, differential machines are checked by specialized laboratories, which ultimately give a conclusion about whether this device can be serviced or not. It is unlikely that it will be possible to check the differential machine for overload characteristics or protection against short circuits, and even more so for the time of operation of these protections, for this special laboratory devices are needed. About, how to check circuit breaker, we detailed in a separate article. Unfortunately at home, it is unlikely that it will be possible to carry out tests, especially to home masters.

However, the main difference between an ordinary automaton and a differential one is residual current devicereacting to deterioration of insulation resistance. It is this unique ability of the device that is recommended to be checked before installation in an electrical switchboard. This should be done at regular intervals, since it is the operation of the mechanism that is aimed at preserving human life and health.

Checking the function of the RCD

There are five effective ways to check the operability of a differential automatic circuit breaker system for leakage current:

• a special button on the switch housing;
• a galvanic cell that generates voltage during a chemical reaction, simply put, a battery;
• imitation of insulation resistance deterioration by connecting a resistor to the device circuit;
• using a permanent magnet;
• using a special precision electronic device manufactured for this purpose.

Let us consider each of the methods for checking the difavtomat in more detail.

Standard button on the case

One of the fastest ways to check both RCDs and difavtomats is to click on the Test button, which is most often located on the body of these electrical switching and protection devices. In order to press it, neither special skills nor special training is required, everyone can perform this procedure.The button is marked with the letter "T" and it is it that imitates the leakage current of an electrical circuit. This current for different differential machines is indicated on the case, so when choosing it, it should be understood that the less leakage current, the more sensitive the protection. That is, even with minimal damage to the insulation of electrical equipment, this section of the circuit is disconnected from the network.

When you press the button for checking the performance of a differential machine, it must immediately turn off automatically, if this did not happen, then the RCD system installed in the switch is faulty. That is, if the test button does not work, subsequent operation will not provide reliable protection during breakdown. It is worth checking in this way with the switch correctly connected to the network, as some difavtomats have an electronic protection circuit and will not work without connecting or when one of the supply wires breaks, whether it is zero or phase. These circuit breakers with built-in electromagnetic RCD must operate and protect a person from being exposed to a dangerous current, even if the neutral lead is cut off.

Testing the differential automaton using the TEST button is demonstrated in the video tutorial:

It is worth noting that for the correct verification of a differential automaton using the "Test" button, it is not necessary to connect consumers, that is, loads to its poles.

Battery cell (battery)

This method makes it possible to check the operability of the system of protection against current leakage in the circuit of difavtomats even directly upon purchase. For this, there is no need to connect to an electric circuit, therefore this method is one of the most mobile and fastest. For this test, you will need a regular battery and two conductors connected to its terminals. It is possible to check in this way only electromagnetic RCDs and differetomats, namely they are considered the most reliable and effective. Plus you need to connect the poles of the machine to the input contact, and minus to the output, as shown in the photo:

This method checks both bipolar circuit breakers rated for 220 volts and circuit breakers designed for three-phase circuits. The fact is that any differential protective device works by comparing the incoming and outgoing currents, and closing the battery contacts at one of the poles of the machine, the bias of these currents is simulated, which triggers the shutdown mechanism.

The video below demonstrates how to test the difavtomat with a battery:

Connect a resistor with a specific resistance

This option of checking the difavtomat for the operation of the protection is more time-consuming since it will require the tester not only to pick up the tool, but also to calculate the resistance of the resistor, which must be connected between one of the outlet pins and the protective earth of the room.

That is, you need to connect a resistor with a certain resistance to the electric circuit, which will play the role of the poor fellow who has come under voltage. Counting it is quite simple, if you remember everyone known from school Ohm's law:

I = U / R

Hence, R = U / I, where the voltage value depends on its value in the network, that is 220 V, and the current is indicated on the differential machine itself. For example, at the indicated leakage current 10 mA: 220V / 10mA = 22 kOhm, and at 30 mA: 220V / 30 mA = 7.3 kOhm. To see this leakage current with a multimeter or tester, you need to set it on the ammeter and connect it in series to the resistor.

This test can be done with a light bulb, but it has a very low resistance and you still have to connect an additional resistor. For a smooth change in current, you can also connect to the circuit Dimmerused as a dimmer control for lamp lighting.

How to test the difavtomat using a resistor is described in detail in the video:

Magnet

The method using a magnet is also effective, but not electric. When you bring the magnet to one or the other side of the cocked difavtomat, a trip will occur.

In this way, in one of the electromagnets that control and compare the current in the circuit, a magnetic field is induced, which will give a signal to turn off the machine. So you can check only electromagnetic, but not electronic difavtomaty.

Electronic meter

In connection with the appearance of these protective devices in the market of measuring electronic equipment, special devices have appeared that, when connected to the network through a socket, make it possible to check not only the operation of the differential machine, but also the time of its operation, as well as the actual leakage current at which it performs protective shutdown.

This device at the level of laboratory research can check and test both protective shutdown devices and other more complex measurements, up to testing high-voltage electrical equipment. But its cost for domestic use is quite high.

The video clearly shows the test of a differential machine with a UNI-T UT 582 meter:

So we looked at how to test the difavtomat for operability with a battery, magnet, and other effective methods. We hope the information provided was useful and understandable for you!

We also recommend reading:

• How to check the RCD for operation
• The reasons for the operation of the differential machine
• Causes of Electric Shock