How to check the difavtomat for performance

Checking circuit breaker functions

In production, differential automata are checked by specialized laboratories, which ultimately give a conclusion about whether this device can be serviced or not. Check the differential circuit breaker for overload characteristics or short-circuit protection, and thus more for the duration of the operation of these protections, it is unlikely to succeed when buying, this requires special laboratory devices. About,

However, the main difference between a conventional automaton and a differential one is residual current devicewhich reacts to the deterioration of the insulation resistance. It is this unique ability of the device that it is recommended to check before installation in an electrical distribution board. This should be done at regular intervals, since it is the actuation of the mechanism that is aimed at preserving the life and health of a person.

Checking RCD functions

There are five effective ways to check the serviceability of the circuit breaker shutdown system for leakage current:

• a special button on the switch body;
• a galvanic cell that generates voltage during a chemical reaction, in other words, a battery;
• imitation of deterioration in insulation resistance by connecting a resistor to the circuit of the device;
• using a permanent magnet;
• using a special precision electronic device manufactured for these purposes.

Let's consider each of the ways to check the difavtomat in more detail.

Standard button on the case

One of the fastest ways to test both RCDs and difavtomats is to press the "Test" button, which is most often located on the body of these electrical switching and protection devices. In order to press it, no special skills or special training are required, everyone can perform this procedure. The button is marked with the letter "T" and it is she who simulates the leakage current of the 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 in the event of a minimal damage to the insulation of electrical equipment, this section of the circuit will be disconnected from the network.

When you press the button for checking the operability of the differential machine, it should immediately occur automatic shutdown of it, if this did not happen, then the RCD system installed in the switch, defective. That is, if the test button does not work, subsequent operation will not provide reliable protection in the event of a breakdown. It is worth checking in this way with the switch correctly connected to the network, since some difavtomats have an electronic protection circuit and without connection or if one of the supply wires is broken, whether it is zero or phase, it is triggered will not. These circuit breakers with a built-in electromagnetic RCD must operate and protect a person from being hit by a dangerous current, even if the neutral supply conductor is broken.

Checking the differential automaton with the TEST button is demonstrated in the video lesson:

Pressing the "TEST" button

It is worth noting that for the correct check of the differential machine using the "Test" button, it is not necessary to connect consumers, that is, the load to its poles.

Galvanic cell (battery)

This method makes it possible to check the performance of the current leakage protection system in the circuit of difavtomats, even directly upon purchase. For this, there is no need to connect to an electrical circuit, therefore this method is one of the most mobile and fastest. For this test, you need a regular battery and two conductors connected to its terminals. This can only be checked by electromagnetic RCDs and difavtomats, namely, they are considered the most reliable and effective. The plus must be connected to the input terminal of the machine pole, and the minus to the output, as shown in the photo:

In this way, both two-pole circuit breakers designed for 220 Volts and switches designed for three-phase circuits are checked. The fact is that any differential protective device works by comparing incoming and outgoing currents, and by closing battery contacts on one of the poles of the machine, the imbalance of these currents is simulated, from which the mechanism is triggered disconnection.

The video below clearly shows how to check the difavtomat using a battery:

Battery use

Connecting a resistor with a specific resistance

This option for checking the difavtomat for protection operation is more time consuming, since it will require the inspector not only to pick up tool, but also calculate the resistance of the resistor that needs to be connected between one of the terminals of the outlet and the protective ground premises.

That is, you need to connect a resistor with a certain resistance to the electrical circuit, which will act as a poor fellow who has fallen under voltage. It is quite simple to count it, if you remember the well-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, with a specified leakage current of 10 mA: 220V / 10mA = 22 kΩ, and at 30 mA: 220V / 30 mA = 7.3 kΩ. To see this leakage current with a multimeter or tester, you need to set it to an ammeter and connect it in series with a 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. To smoothly change the current, you can also connect to the circuit Dimmer, used as a dimmer for lighting lamps.

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

Connecting a resistor to a circuit

Magnet

The magnet method is also effective, but not electrical. When the magnet is brought to one or the other side of the cocked difavtomat, a shutdown will occur.

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

Electronic meter

In connection with the appearance of these protective devices on the market of measuring electronic equipment, special devices have appeared that, when connected to a network through an outlet, give the ability to check not only the operability of the differential machine, but also its response time, as well as the real leakage current at which it performs a protective shutdown.

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

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

Application of the RCD meter

So we looked at how to check the difavtomat for performance 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 an RCD for operation
• Reasons for the operation of the differential machine
• Causes of Electric Shock