Why does the RCD trip - causes of problems and ways to eliminate them

If the iron and electric kettle do not turn off the automatic switches, then the problem is in the vacuum cleaner! Call your nearest service center and find out the approximate cost of repairs. I think the repair will not be profitable.

either weak plugs (I recommend 25 A), or the old plugs are already worn out (replace), or the vacuum cleaner has an interturn short circuit in the coils (check in a workshop)

The power is too high. In our house, all the wiring is made of aluminum wire of a small cross-section and there is a notice hanging up - the power is no more than 2 kW. If it’s the same in your home, then everything is clear. For our washing machine, we ran a separate wire from the panel.

It depends on what kind of traffic jams there are and what kind of wiring. )) And if there are also automatic traffic jams, then immediately throw them in the trash and install normal fuses instead)

What's broken in the vacuum cleaner? Determine for yourself in 5 minutes. Decide what to do next, repair it yourself, take it to a workshop, buy a new one. The vacuum cleaner does not suck, smokes, burns, does not turn on, shorts out, shorts out, cuts out plugs, what should I do? How to clean a vacuum cleaner filter? (10+)

Attention! All repair, cleaning and maintenance work on the vacuum cleaner must be performed with the power cord disconnected from the mains.

Expert opinion

It-Technology, Electrical power and electronics specialist

Ask questions to the “Specialist for modernization of energy generation systems”

When plugging the hair dryer into the socket, the plugs were knocked out. If you insert any plug into a socket, it knocks out again - what should I do? The cause of the malfunction does not have to be in the wiring; the insulation at the input to the panel or at the machine may be damaged, or one of the sockets may short out. Ask, I'm in touch!

How does an RCD work?

The operation of an RCD is based on a comparison of currents flowing through the phase and neutral conductors. If they are equal, the device operates normally and passes power to the apartment. If they differ, it means there is a problem somewhere. The RCD cuts off the voltage on the protected line.

Operating principle of the residual current device

The problem means a condition when the currents in the phase and neutral conductors are unequal. To compare these indicators, a special differential transformer is provided in the RCD. Its primary windings are phase and neutral wires, through which current enters the apartment. They are included in antiphase. At the same currents, the windings create magnetic fluxes equal in magnitude but opposite in direction. Their geometric sum is zero. With unequal currents, the magnetic fluxes are different and induce an EMF on the secondary winding of the transformer. The secondary signal goes to the circuit controller, and from it to the actuator - an electromagnetic relay. It disconnects the output L terminal of the RCD from the input terminal.

Why does the RCD trip when turned on?

Most often, the protection is triggered by faults in the electrical wiring or a violation of the insulation of electrical appliances and the appearance of leakage current. Let's look at cases of operational tripping of an RCD, immediately upon switching on.

4) Damage to the power cable

One of the reasons why an RCD trips is damage to the electrical wiring. For example, you drilled into a wall and damaged the cable laid inside.

This type of damage is the most difficult to detect and repair. In some cases, you will have to replace part of the wires or the entire electrical wiring.

This damage can occur in different situations:

• moisture entering the junction box;
• violation of insulation during repair work;
• overheating of strands and damage to insulation in junction boxes;
• When doing open wiring in the attic, mice could chew on it.

5) Electrical appliance malfunction

The most common reason for tripping the RCD is a malfunction of an electrical appliance (washing machine, water heater, etc.). If the insulation of the grounded case is broken, the plug or socket is damaged, a leakage current appears, causing the protection to operate.

To determine a faulty device, all electrical appliances connected to the triggered differential relay are turned off. If there is no response, the devices are connected in series to the network until the RCD is turned off again. The device that triggered the protection is faulty and must be repaired or replaced.

False alarms of the protective device

The residual current device is imperfect, and neither are the networks to which it is connected. Especially if the wiring is old or its design was approached irresponsibly. Therefore, RCD owners periodically encounter false alarms.

Note! Some models of RCDs and differential circuit breakers are susceptible to false alarms at night. The reason lies in the reduction in load on the transformer substation at night, which is why the voltage in apartments jumps above the permissible standards for protective devices. If a three-phase RCD is triggered, then all 3 phases are turned off simultaneously.

Knocks out the RCD when you turn on the washing machine

If the protective device is triggered when the washing machine is turned on, then the most likely reason is that the unit is connected incorrectly. Need to check:

• connecting the washing machine to grounding;
• does the body of the machine touch a metal bath or pipes;
• integrity of the cable supplying the unit.

Connecting a washing machine through an RCD
If the washing machine is old, then the RCD knocks out due to insulation problems. Please note the following:

• integrity of the insulation of the internal wiring of the machine;
• no leaks on the engine or other electrical components;
• Is the motor winding shorted?

The RCD on the water heater is triggered

Triggering of a protective shutdown device on a water heater is possible for a number of reasons:

• damage to the insulation of the water heater or the cables from which it is powered;
• touching metal parts of the device with exposed wires;
• boiler leak;
• excessively high humidity in the room (condensation forms);
• The RCD does not match the power of the water heater, so it shuts down due to overheating.

Connection diagram of the water heater to the electrical network

Often the problem lies in damaged insulation. The boiler has a heating element. It is subject to periodic heating and cooling. Therefore, the insulation of the heating element is not in the most gentle conditions and is subject to wear. The problem is also typical for other household appliances. Irons, kettles and electric ovens also contain heaters.

Knocks out the RCD when the lights are turned on

Typically, problems arise after replacing apartment electrical wiring or installing new chandeliers and lighting fixtures. Please note the following:

• absence of strands without insulation in junction boxes;
• whether putty or cement has got on the wiring and live parts;
• whether the wire in the chandelier is frayed;
• integrity of cable insulation in switches;
• no broken wiring in the walls.

Often the fault lies in a broken cable in the wall. This happens after drilling. The drill from the hammer drill gets into the cable and damages the insulation of the phase, neutral and ground.

Protection tripping without load

To make sure that the RCD is triggered without load, you will have to disconnect electrical appliances from the sockets in the apartment and turn off the lights everywhere. If the safety device still knocks out, there are 3 possible reasons:

• the wiring is old, its insulation is cracked and conducts leakage currents to the ground;
• During repairs, the cable in the wall was damaged;
• The RCD is faulty.

Triggering of the RCD due to current leakage to the ground
. To determine this problem, it is necessary to disconnect the phase wire coming from the RCD. If the triggering continues, then something is clearly wrong with the protection.

Vacuum cleaner device

The main part of vacuum cleaners is designed approximately the same. The vacuum cleaner has an inertial type air pump (snail). This pump is driven by a brushed electric motor. The pump sucks in air.

What kind of lighting do you prefer?

Built-in Chandelier

Air is sucked in through the nozzle, passes through the pipe that you hold in your hand when cleaning, through the hose, and enters the filter. The filter can be of several types: bag, water, cyclone. Swallowed dust, dirt, and debris settle in this filter. We then throw them out of it.

Next, the air enters the fine filtration filter (or filter system). These filters or filters catch small dust particles that have slipped through the main filter so that they do not enter the pump, engine, room air, or our lungs.

After the fine filter, the air enters the volute pump and is blown out into the space of the room being cleaned.

Common RCD faults

The residual current device contains moving parts. The mechanics of cheap models are not reliable. If the RCD is introductory, the current of all consumers in the apartment flows through it, which inevitably leads to heating of the terminals and relay contacts. These factors contribute to the safety device being knocked out.

The "test" button is broken

The “text” button is used to check the functionality of the RCD. But often it leads to its malfunction. The safety device should be checked every month. Due to frequent testing, the “test” button is subject to a number of negative factors:

• jamming from too much pressure or dust;
• breakdown of moving parts;
• dirt getting on the conductive contacts of the button.

The activation mechanism is broken

It does not require much effort to turn off the RCD. The lever acts on a special latch that releases the contacts. After which the device turns off. If there is a breakdown in this mechanism, then involuntary tripping of the RCD is possible.

The problem often appears when it gets hot. Under the influence of heat, the parts of the mechanism change their geometric dimensions, which leads to the release of the latch and disconnection of the RCD. Another triggering factor is vibration. If the mechanism is on the edge, it will work even with light taps. If the lever itself or the rods break down, the RCD simply does not turn on.

Important! Such faults can be easily identified with a screwdriver. It is necessary to turn on the RCD and tap the body with a slight force with the handle of the tool. It is advisable to do this with the machines turned off. If the problem is purely mechanical, it will manifest itself without tension.

Current leakage inside the RCD

A common cause of such a malfunction is dust and moisture entering the protective device. This leads to leakage currents in the RCD itself. Dirt can transfer electricity between any conductive parts and even supply phase voltage to the device controller, which will lead to burnout of the electronics.

Checking the functionality of the RCD

The malfunction is typical for devices located not in the shield, but in the open air. In some cases, to correct the situation, it is enough to remove the protective device and let it dry thoroughly at temperatures of 30-50°C. If drying helps, then the problem is moisture. In the future, it is necessary to protect the device from water.

Triggering of RCDs from some household appliances

Many household and industrial devices are equipped with filter capacitors between the power wires and the device body. For example, PC system units. The presence of capacitors causes leakage current to ground. Usually it is small enough that the RCD will not be knocked out. However, if there are enough such devices, the leakage currents on the grounded housings of household appliances will add up and lead to the operation of the protective device.

This most likely refers not to a malfunction of the RCD, but to incorrect selection. When choosing a protective device, you should pay attention to the current IDn at which it turns off.

Important! Apartments without grounding have one unpleasant feature. If you use a multimeter to measure the voltage between the metal case of the system unit and the heating radiator, the measuring device will show about 110 V. When you touch the measured points with your fingers, you will feel a characteristic tingling sensation from the flow of current. A similar effect is possible thanks to capacitors connected to the PC case. Of course, the described experiment should not be repeated.

Incorrect connection of the protective device

Connection errors are detected immediately after installation of the RCD or other electrical equipment. For example, a previously installed protective device began to break after connecting the socket. So that's the problem. It is necessary to pay attention to the connection of the phase, neutral and ground wires to the sockets.

Another option is to knock out a new, newly installed RCD. The previous protective device worked correctly. No changes were made to the apartment wiring. In such a situation, you should check the connection of the new RCD. Even experienced craftsmen make mistakes.

Troubleshooting

Knocking out when switching on new electrical wiring

When wiring is connected for the first time, troubleshooting should be done by checking the correct installation.

The automatic machine is first turned on in testing mode. If it works, then everything is fine with the device itself. Further actions are performed in the following sequence:

• it is necessary to make sure that there is no load;
• the machine turns on and when it is knocked out, it is concluded that the conductors are connected incorrectly;
• the connection to the N terminals of the neutral wire is checked, to the L terminal - the phase wire;
• the lower contacts of the machine are checked for correct connection of cables from the line to be monitored;
• An attempt is made to activate the protective device.

It is necessary to check where the “zero” wire comes from. It is supplied to the upper terminal from the zero bus. The “zero” is connected to the bottom contact from the line; it comes from the box. If the device is knocked out again, the reason must be sought in the connections in the switchboard.

Checking the shield

Most often, errors made during installation can be found in the panel - “zeros” from different lines are mistakenly connected or the connection points are mixed up.

When a fault occurs in the switchboard of a difavtomat, the cause may be an incorrect connection of the wires

Such mistakes are usually made by specialists who are accustomed to working only with circuit breakers, for whom it makes no difference which line the neutral cable is supplied from, since the devices themselves control the current on the phase cable

For an RCD or a differential circuit breaker, on the contrary, this is very important, since they react to the difference in current values ​​in the phase and neutral wires

After checking the correct connection in the distribution panel, you can turn on the machine. If it turns off again, you should make sure that the wires extending from the box to the outlet are connected correctly - the ground wire and the “zero” wire are no less often confused. If everything is correct, the machine should turn on and begin monitoring.

If you have doubts about the performance of the difavtomat itself, you can check it as follows. Using an indicator screwdriver, there is a “zero” in the socket, which is connected to ground. Since no current flows through the phase and neutral wires without a load, the machine will not work. When you connect a load, even from a light bulb, the device will turn off. In the zero wire the current value will be 2 times less than in the phase wire. This will trigger the electromagnetic release.

Checking the circuit

When a circuit breaker trips due to a short circuit, the cause is easiest to find. A device operating from a controlled line, as a rule, does not work. It is also equipped with fuses that blow, the body may be slightly blackened, and the wires may be slightly melted.

When connecting several devices to the line at once, the faulty device should be disconnected, and then the machine should be turned on again, which should immediately begin monitoring.

In case of a secondary shutdown, you should pay attention to the period during which this happened. If the device turns off immediately, it means it is shorting somewhere else

Finding out the reason for the operation of the machine during a short circuit in the controlled network

Then the load should be turned off gradually - remove one consumer, turn on the machine and wait for its reaction. If the device is put under control, there is a malfunction in the disconnected device. If there is no control, we disconnect the next consumer.

Overload

If the machine does not turn off instantly when the load is connected, but some time later, we can conclude that there are overload currents, the magnitude of which is not enough for immediate operation.

Triggering of the automatic circuit breaker during overload can occur due to the connection of too powerful consumers

For this reason, the shutdown occurs due to the thermal release triggering when too many powerful appliances are connected.

Normal tripping of the RCD

Normal operation of the protective device indicates one of two possible problems:

1. Wiring insulation is damaged. You'll have to look for the location of the problem.
2. The man was electrocuted. We need to find the victim.

Violation of cable insulation

This happens periodically on old equipment. For example, a refrigerator is subject to continuous vibration due to the operation of the compressor. It is capable of grinding PVC insulation of internal wires on sharp edges and metal parts. This will result in a short circuit to the chassis.

Next are two options. If the refrigerator is grounded, the RCD or circuit breaker will trip. The apartment will turn off. The dangerous factor will be eliminated. If there is no grounding, the RCD should again trip. But this will not happen when the refrigerator body is sufficiently well insulated from the floor (ground). This situation is extremely dangerous. The refrigerator will be under mains voltage and “wait” for human touch.

Phase touch trigger

The refrigerator body remains energized. Its metal surface is under a potential of 220 V, a person touches the body, then a differential current begins to flow through the body into the ground. The RCD detects the leak and turns off the power to the refrigerator or apartment. The person is saved, and most likely he will not even feel anything. After this, you have to find the current leak. It is necessary to find out in which electrical appliance the insulation damage occurred.

In another case, a person accidentally touches a phase wire. For example, if you carelessly replace an outlet. The RCD will operate and protect a person from electrical injury. This is the main task of the residual current device.

Main reasons for shutdown

In fact, there are a lot of culprits for the operation and they can be of a very diverse nature, and, accordingly, the repair method. First, let's look at why the RCD is triggered, after which we will provide you with instructions for self-repairing faults.

Today, the following reasons are known why the product knocks out:

1. There was indeed a current leak in the network. This may be due to the fact that the electrical wiring is old, because... In any case, the insulation has already dried out over time and in some areas the wire is exposed. If you have recently replaced the electrical wiring in your apartment, then the wires may have been connected poorly in certain places, or you may have accidentally pierced the insulation of the hidden wiring when driving a nail into the wall.
2. The culprit may be electrical appliances that are protected by this device. Here, either the cord that connects to the network has failed, or the internal parts are “broken” (for example, the motor winding or the heating element of the water heater).
3. Incorrect installation of protective automation, as a result of which the RCD does not work correctly and is triggered periodically. We have already provided instructions on how to properly connect an RCD with your own hands, so we recommend that you familiarize yourself with it.
4. It is possible that when purchasing a protective automatic device you chose the wrong characteristics, and a false alarm occurs. We talked in detail about how to choose an RCD in the corresponding article.
5. A residual current switch (DVT, as it is also called) can be knocked out due to a person touching a bare current-carrying conductor. Don't forget that this is its main purpose.
6. A malfunction of the mechanism itself may be one of the reasons. For example, the “Test” button is stuck or the trigger mechanism is damaged, which will be triggered at the slightest vibration.
7. Often a shutdown occurs due to improper placement of the DVT in the electrical wiring line. Look at one of the examples: a diagram for connecting an RCD in a single-phase network to find out where to install it.
8. A short circuit between ground and zero during electrical installation work may result in a shutdown. Although the rules of the PUE are strictly prohibited from connecting the grounding to the neutral conductor, some electricians ignore the prohibitions and do everything their own way, citing the fact that this method will protect a person from electric shock (although in fact this only increases the danger).
9. Weather conditions directly affect the performance of the device. For example, in wet weather, if the switchboard is installed outdoors, it may trigger due to dampness in the internal mechanism. In turn, the accumulation of moisture inside the product can cause a leakage current, as a result of which the mechanism will react. It should also be noted that in cold weather the RCD may sometimes not turn on in a dangerous situation. This is due to the fact that sub-zero temperatures negatively affect microcircuits, which cause them to fail. By the way, during a thunderstorm, there are cases when the protection is turned off, which is caused by the influence of lightning, which amplifies minor current leaks present in the house (or apartment)
10. Well, the last nuance, which is closely related to the previous one, is increased humidity. If you installed hidden electrical wiring, then covered the route with putty and decided to immediately check the quality of the work done, a shutdown may occur. This is due to the fact that wet solution is a good conductor, which can cause leakage through the smallest cracks in the wiring. Wait until the solution has completely set, then check again whether the RCD is triggered or not, because Perhaps the lever no longer disengages.

Be sure to watch the video lesson, which clearly shows the erroneous connection:

Video review of incorrect device connection

We have looked at what could be the reason for the tripping of the residual current device. Now, of course, we need to provide you with instructions on how to solve the problem yourself.

How to find the cause of the trigger

The easiest way is to call a specialist who constantly encounters a similar problem, has experience and will quickly deal with the problem. If you decide to look for a current leak on your own, you need to check the following:

1. Find out whether the residual current device is working properly. See how it behaves without load and whether it triggers when tapped with a screwdriver.
2. If the RCD is working properly, you will have to look for a leak in the apartment. The problem lies either in the wiring or in household electrical appliances (oven, refrigerator, washing machine).
3. If you have an electric heated floor, you should turn it off and see whether the RCD is triggered or not. Floor heaters often short to ground.
4. It is advisable for residents of private houses to check submersible pumps. They are susceptible to depressurization and short circuits to the housing.

Important! If the residual current device trips when you connect portable electrical appliances to an outlet, do not touch their metal parts. Such devices include kettles, irons, curling irons or electric soldering irons. Knocking out of the RCD indicates problems with the insulation of the devices. Touching them may result in an electric shock.

If the RCD has tripped, you need to figure out what exactly the problem is. Usually the malfunction lies in damage to the insulation of household electrical appliances or water entering the wrong place. In such situations, it is enough to repair the damaged cable or dry the device.

Another reason for knocking out is a malfunction of the protective device itself. This happens much less often. In this case, you will have to replace the broken device with a new one.

Reasons for knocking out a machine gun

So, let's move on to the main question of the article, why does the machine knock out - what are the reasons for this trouble? Let's start with the fact that there are five such reasons:

1. Overload in the electrical network.
2. The circuit breaker itself is faulty.
3. Malfunction of one of the household appliances.
4. Light fixture malfunction.
5. Short circuit in electrical wiring.

What is network congestion? In essence, this is a current load that exceeds the rated one determined by the machine itself. For example, for socket groups, machines with a current rating of either 16 amperes or 25 are most often used. This corresponds to either 3.5 kW of withstand power or 5.5 kW.

Now imagine a situation where the socket group to which a circuit breaker with a current rating of 25 amperes is connected contains several household appliances, the total power of which exceeds the rated power. For example, a washing machine with a power of 2.5 kW is turned on, an air conditioner - 2 kW, an electric kettle - 1.5 kW. The total power of the three devices will be 6 kW. That is, the machine simply cannot withstand such a load and will definitely turn off (break) the circuit.

What to do in this case?

• Monitor the total power of connected household appliances.
• Redistribute the connection of devices to different socket groups.

But under no circumstances should you change the machine itself to a higher denomination. The thing is that everything will depend on the electrical wires laid in the wiring diagram in the apartment or house. If the circuit used copper wire with a cross-section of 2.5 mm², then a machine with a nominal value of 25 amperes is installed in it, no more. If the wiring is aluminum of the same cross-section, then the switch is 16 amps.

Machine defect

How high is the probability that due to a malfunction of the device itself, the machine will be knocked out? The probability is negligible, especially when it comes to branded models. But it is there. Therefore, the only way to be sure that this is the cause of the knockout is to replace it with another device. Or you can reconnect the circuit to a nearby circuit breaker in the distribution panel. If in this case the machine knocks out, then the reason is completely different.

And one moment. Like any device, the machine has its own service life. Wear of various parts leads to a decrease in its technical characteristics. This also applies to the release contacts, which are responsible for knocking out due to an increase in the current load.

Malfunctions of household appliances

Household appliances themselves can cause the machine to break out. How can this be checked?

1. Unplug all connected devices from the sockets.
2. If the machine is not knocked out in this position, then start connecting each device separately.
3. As soon as the machine turns off, it means that the household appliance plugged into the outlet is faulty. It will have to be repaired or replaced with a new one.

Some equipment is connected to power not through sockets, but, so to speak, directly. For example, air conditioners or dishwashers. The only way to check them is to disconnect them from the machine in the switchboard.

Defects in lighting fixtures

Sometimes situations happen that the machine goes off when the chandelier turns on. This indicates that there is some kind of malfunction in it.

• There is a short circuit in the light bulb base. To do this, you will have to unscrew all the light bulbs, and then screw them in again one by one and turn on the lighting fixture. As soon as the machine turns off, it means that the light bulb in which the base is broken has been found. It will simply need to be replaced.
• The contact between the power wire and the wiring inside the chandelier has burnt out. You just need to inspect the contact, clean it and insulate it well.
• LED chandeliers include a 12 volt transformer. So, it is precisely this that can cause the machine to be knocked out due to a short circuit inside. It will be necessary to remove the chandelier and change the transformer.

Defects in electrical wiring

There are two reasons:

1. Poor contact in the socket.
2. Deterioration of insulation in the conductor.

In the first case, you need to open the socket, find the burning area, clean it and correctly connect the wire to the socket. The second case is more complicated. It usually concerns a short circuit that occurs within the electrical circuit in an apartment or house. It is simply impossible to find the location of the short circuit without a special apparatus. Not every average person has even heard of him. This device is called a locator.

It is good if the wiring in the apartment or house was done in an open way. Having found the location of the short circuit, you can easily correct the defect. If the wiring was hidden, then you will have to open the discovered short circuit (remove the finishing and plaster), correct the defect, and then seal the hole by carrying out finishing work.