Why RCD knocks out: causes of operation and troubleshooting

Main reasons for disconnection

In fact, there are a lot of culprits for triggering and they can be of the most diverse nature, and, accordingly, the method of repair. First, we will consider why the RCD is triggered, after which we will provide you with instructions for self-repair of faults.

To date, 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 wiring is old, because. In any case, the insulation has already dried out over time and in some areas the wire is bare. If you have recently replaced the electrical wiring in the apartment, then there may be a poor connection of wires in certain places, or you accidentally pierced the insulation of hidden wiring when you drove 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 is out of order, or the internal parts are “broken” (for example, the motor winding or the water heater heater).
3. Incorrect installation of protective automation, as a result of which the RCD does not work correctly and periodically trips. We have already provided instructions for the correct connection of the RCD with our own hands, so we recommend that you read it.
4. Perhaps, when buying protective automation, 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 differential current switch (DVT, as it is also called) can be knocked out due to a person touching a bare current-carrying core. Do not forget that this is its main purpose and is.
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 work at the slightest vibration.
7. Often a trip occurs due to improper placement of the DVT in the wiring line. View one of the examples: RCD connection diagram in a single-phase network. to find out where to install.
8. Shorting ground and zero during electrical work may result in a shutdown. Although the rules of the PUE strictly prohibit connecting ground to a neutral conductor, some electricians neglect the prohibitions and do everything in their own way, referring to 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, operation may occur due to the appearance of 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 here that in case of frost, 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 fail. By the way, during a thunderstorm there are cases when the protection is cut down, which is caused by the influence of lightning, which enhances the minor current leakage present in the house (or apartment)
10. Well, the last nuance, which is closely related to the previous one, is high humidity. If you have carried out the installation of hidden electrical wiring. after which they covered the track with putty and decided to immediately check the quality of the work done, a shutdown may occur. This is due to the fact that the wet solution is a good conductor, which can cause leakage through the smallest cracks in the wiring. Wait until the solution is completely set, then check again whether the RCD is working or not, because. Maybe the lever isn't cutting out.

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

Video review of incorrect device connection

What could be the reason for the operation of the residual current device, we examined. Now, of course, you need to provide you with instructions for solving the problem with your own hands.

Testing the RCD for serviceability

To eliminate unsuitability, you need to make sure that the protection connection process is carried out correctly. Testing can be done by performing some operations:

1. Disable automatic. Performing this action will eliminate the impact on the RCD of all objects connected to it.
2. Disconnect the outgoing conductors by removing them from the pre-loosened terminal.
3. Check the function of the locking lever. Set it to the "on" position and lightly tap on the case. A spontaneous change in the position of the mechanism at the time of the option indicates a failure of the lever, which means that the RCD is not suitable for further operation.
4. Turn on the machine (the locking mechanism must be in working order). Automation should not react, since the conductors are disconnected at the output, but its response will be the basis for replacing the device.
5. Testing by pressing the "T" button. A working unit will respond with an instant shutdown.

Causes of malfunctions in the washing machine itself

When the electrical wiring was inspected and the identified problems in it were eliminated, however, the RCD works again, which means that the malfunctions occurred in the machine. Before inspection or diagnostics, the unit must be de-energized, make sure that there is no water in the machine.Otherwise, there is a high risk of electrical and possibly mechanical injuries, since the machine has rotating units and components.

There are a number of factors why plugs, a meter or an RCD knock out:

due to breakage of the plug, power cable;

Damage to the plug, power cable

Diagnostics invariably begins with an electrical wire and plug. When used, the cable is subjected to mechanical stress: it is crushed, overlapped, stretched. Due to a malfunction, the plug and electrical outlet are not making good contact. The cable for faults is tested with an ampervoltmeter.

Short circuit of thermoelectric heater (TENA)

Due to the poor quality of water and household chemicals, the thermoelectric heater is “eaten up”, various foreign substances and scale build up, the transfer of heat energy becomes worse, the thermoelectric heater overheats - this is how a bridge happens. As a result, the electric meter and plugs are knocked out. To diagnose the heating element, disconnect the power cable and measure the resistance with an ampervoltmeter, setting the maximum value on the “200” Ohm label. In the normal state, the resistance should range from 20 to 50 ohms.

Sometimes the thermoelectric heater closes to the housing. To filter out such a factor, the leads and grounding screws are measured in turn for resistance. Even a small value of the ampervoltmeter indicates a bypass, and this is a factor in turning off the residual current device.

Failure of the filter to suppress interference from the mains

The filter is required in order to stabilize the electrical voltage. Network drops render the node unusable, when the washing machine is turned on, the RCD and traffic jams are knocked out. In such a situation, the filter needs to be replaced.

The fact that the mains filter to suppress interference from the mains has shorted out is indicated by the reflow elements on the contacts. The filter is tested by calling the incoming and outgoing wiring with an ampervoltmeter. In certain brands of machines, an electrical cable is installed in the filter, which equally needs to be changed.

Motor failure

The cause of a short circuit in the electrical wiring of the electric motor is not excluded during long-term use of the unit or violation of the integrity of the hose, tank. The contacts of the electric motor and the surface of the washing machine ring alternately. In addition, plugs or a circuit breaker are knocked out due to wear of the motor brushes.

Failure of the control button and contacts

The electric button is used most often, in connection with this, inspection should begin with checking it. During the initial examination, you can notice the contacts that have oxidized and worn out. An ampervoltmeter checks the wires and contacts leading to the control panel, electric motor, thermoelectric heater, pump and other units.

Damaged and frayed electrical wires

Worn electrical wires usually form in an inaccessible place in the washing machine. When the unit vibrates during the process of draining water or squeezing, the electrical wires rub against the body, after a certain period of time the insulation is frayed.An electrical short on the case becomes a consequence of the fact that the machine is triggered. Areas of damage to the electrical wire are determined visually: carbon deposits appear on the insulating layer, darkened melting zones.

Checking the performance of the RCD

In total, there are five methods to check the performance of this protection, and each of them is available at home:

1. Using the button provided by the design of the device.

The use of a battery is also a galvanic cell that generates voltage.

Connecting a resistor - simulates an increase in network resistance similar to that that occurs when the integrity of the electrical network is violated.
The use of a permanent magnet.

With the help of special purpose equipment.

Each of the proposed methods has its own characteristics, so they should be considered separately.

Regular button

The easiest and fastest method is to check not only the difavtomat, but also the usual RCD. Each of the devices has a "TEST" or "T" button, in order to press it, you do not need to have special skills or special knowledge. Pressing it triggers a reaction simulating a power outage. The strength of the current that turns on when the button is pressed corresponds to the rating indicated on the case (device sensitivity).

When you press the test button, a working device will instantly break the electrical circuit and the entire network will be turned off, if nothing happens after pressing it, the RCD does not function, that is, there is no protection against breakdowns. The use of such a device is strictly prohibited, because the user is absolutely not protected from current leakage.

It is also worth remembering that in modern difavtomatov there is a controller that will not allow the device to work when the mains is turned off or the supply wires are broken (zero or phase does not matter), so you need to check them on a working mains. At the same time, only the closure of the electrical network affects the test, and the presence or absence of consumers does not matter

This type of protection is called an electromagnetic RCD, it is designed to protect a person in any situation, including a break in the “zero”.

Battery

This method is good because it allows you to verify that the RCD is working right in the store without connecting it to the network. To do this, you need a battery and wiring or paper clips to connect it to the machine.

The verification algorithm is as follows:

• we connect the battery in the same way as in any device (minus to the output, and plus to the input);
• press "T", if the device worked - it is working.

This method can be used to check both three-phase and two-phase devices for 220 volts. The secret is that the operation of the RCD is based on comparing the potentials on the contacts. Therefore, if you connect even a simple battery, the difference between the input and output potentials must be recorded by the device.

Resistor

This method requires the tester not only to have a device, but also certain knowledge (the ability to calculate the resistance of a resistor). To do this, a resistor is connected between ground and the socket outlet. The resistor in this case will be in the role of an electric shocked person. According to Ohm's law R = U/I. The voltage in this formula is 220 Volts, because we plugged one end into an outlet. Next, we connect the multimeter to the resistor and see the "amperage" of the current leakage.Using the formula (as an example, 10 mA: 220V / 10mA = 22 kOhm), we set the Ohm value necessary for the test.

Also, this test can be carried out with a light bulb, with a dimmer connected, instead of a resistor.

Magnet

This method is also applicable to a disconnected difavtomat, because it has nothing to do with electricity. If you introduce a unidirectional magnet into the magnetic field of the electromagnets responsible for cocking the machine, it will turn off. The magnetic field simulates the resonance at which the device should turn off. Unfortunately, the method has a drawback - they can only check the electromagnetic RCD.

Special meter

As soon as differential automata appeared on the market, they were followed by the appearance of special measuring instruments. They allow you to check not only the operability of the RCD, but also all other protections, display data on leakage and response time.

The devices are easy to use (you just need to plug into a power outlet), and the accuracy of the study is commensurate with laboratory expertise. The only negative is the price of the device, it makes no sense to buy one for domestic use, but even in a small enterprise, it will be a fairly profitable purchase.

What to do if the RCD turns off

Since the connection of the RCD is carried out strictly according to a certain scheme, the algorithm for determining the malfunction will always be approximately the same. First of all, it is necessary to determine the reason - a false alarm occurs or nevertheless the shutdown is performed in the normal mode.

Here it is necessary to consider exactly how the RCD can be turned off.

• The most obvious reason is when trips occur immediately after the installation of an RCD or an additional electrical circuit (socket or other point).Here you just need to double-check the connection diagram and the performance of the device itself. In general, these are installation errors and it makes no sense to dwell on them in detail.
• The next simplest case is if there is no grounding in the house, and a person touched the body of an electrical appliance and a trip occurred. This is a direct indication of a malfunction of this device - it is necessary to review its electrical equipment - power cord, etc.

However, if the wiring is old, then there is a small chance that the phase wire will come into contact with the ground, for example, with the fittings of the floor slab or similar conductor. In the first case, it is necessary to change the RCD, and in the second - all the wiring (or, at least, look for the place of damage and fix the problem).

• If the RCD does not turn on after tripping, then first of all, you need to remove the plugs of all electrical appliances from the sockets and try to lift the device lever again. The inclusion of the RCD in the operating mode indicates the need to check all the devices - they can be plugged into sockets one by one and then the faulty one will immediately show itself. If the RCD does not turn on further, then the wires recline from its lower terminals and again try to raise the lever. The inclusion will indicate a wiring malfunction, otherwise it is most likely a malfunction of the RCD itself.
• When the residual current device just periodically knocks out during operation, then this is the most unpleasant breakdown in terms of diagnostics. First of all, here you need to look to see if any parameters of the electrical circuit have changed. This may be the appearance in the house of a new device, for the power of which the RCD is not designed or it has a switching power supply.If nothing has changed in the circuit, then it is necessary to monitor, after which knockouts occur - this may be the operation of one of the devices in the maximum load mode, high humidity, etc. If there is no obvious reason, then you will have to consistently double-check everything possible - from the serviceability of the RCD and the correct selection of the setting to each of the links of the protected electrical circuit.

Features of choosing an RCD connected to a water heater

In domestic conditions, storage and instantaneous electric water heaters are used. Using the device protects the equipment from electric leakage or fire. RCD for water heater installed directly in front of the device itself, and electrical energy passes through it, feeding the equipment. In cases of current leakage, the device detects changes and automatically turns off the power system. For this, the device is equipped with special sensors and switches.

According to safety requirements, the RCD installed on the water heater must be supplemented with grounding. Also, to protect equipment from overloads or short circuits, boilers are additionally equipped with difavtomatami.

RCD and difavtomat for additional protection of equipment

For boilers with a power of not more than 2.3 kW, it is worth using a device designed for 10 A. More powerful water heaters that use from 5 to 8 kW should be equipped with a device for 30 - 40 A.

In order to calculate the leakage current, you need to take 0.4 mA for 1 A. When installing an RCD at a great distance per 1 m of cable, add 1 mA additionally.

The most convenient option for mounting an RCD is a DIN rail mount, or a separate unit that can be plugged into a power outlet.

Before buying a boiler, you need to clarify the location of the device. It can be installed inside the network cable or under the water heater body.

Before buying a boiler, you need to clarify the location of the device. It can be installed inside the mains cable or under the water heater body

Troubleshooting

By checking each individual device, you can find out which one has a malfunction. When you connect faulty equipment to the RCD, protection will automatically work. The most common malfunctions occur in the operation of washing machines, electric ovens and water heaters. To solve this problem, you should not open the equipment yourself. To fix the breakdown, you should contact the service center or call a specialist at home.

If the problem is in the old electrical wiring, then often it has to be changed completely. If the lines have been laid recently, then it is worth looking for errors in the connections or wiring. It is necessary to inspect junction boxes, sockets. If the automation works when the lighting is turned on, then the reason may be in the lighting fixture itself. Also, do not neglect to check the cable along the entire line. If there is open wiring in the room, this makes the task easier. To diagnose closed wiring, you should use a special device. It helps to find the place of cable break.

Clamps for measuring current leakage

Finding out the reasons for the tripping of the RCD is a long and troublesome process that requires a lot of time and patience.

How to turn on the RCD after tripping

If a trip occurs, then it is necessary to find the cause of the accident and eliminate it. Let's look at the algorithm of actions what to do if the RCD knocks out or trips:

• one.Return the RCD handle to its original position. If the RCD is cocked (turned on), there may have been a short-term current leakage or a person touched the live parts. In this case, it is necessary to check the operability of the device by pressing the “Test” button.
• 2. If the RCD does not turn on, then the device itself or the wiring may be faulty. If triggered immediately after installation of the device, incorrect installation is possible. In this case, troubleshooting is performed.
• 3. Turn off all circuit breakers connected after the difrele. If they are single-pole, then, in order to exclude current leakage from the neutral wire, it is disconnected from the zero bus.
• 4. Return the RCD handle to its working position. If it cocks, then check the serviceability of the device with the “Test” button. If the RCD does not cock or is not turned off by the button, then it is faulty and must be replaced.
• 5. Sequentially turn on the previously disabled machines. If the protection works when one of the circuit breakers is turned on, then there is a problem in the wiring or electrical appliances connected to this machine.
• 6. Turn off all electrical appliances in this line from the sockets or disconnect from the terminal blocks. Turn on RCD.
• 7. If it is not possible to cock the RCD, then the wiring is faulty and the junction boxes need to be revised with sequential disconnection of individual sections of the circuit. If the RCD turns on, then one of the electrical appliances is faulty.
• 8. Sequentially turn on all disconnected devices, while checking their operation. When connecting to a network or operating a faulty device, protection should work.
• 9. Turn off the faulty device and send it in for repair. Connect other devices.
• ten.Arm the RCD and check it with the “Test” button. If the difrele does not turn on, repeat p.p. 6-9.

When repairing and maintaining electrical networks, it is important to know why the RCD knocks out. It will help faster find and fix faults and make the operation of electrical appliances safer

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How is the device diagnosed?

To fix the problem, you need to properly diagnose the system. It is checked whether the device circuit is connected correctly. Installation errors, unfortunately, are quite common. They lead to false alarms in the system.

Sometimes the RCD can knock out even when all devices are disconnected from the electricity network. In this case, it is worth considering that the person initially bought the wrong device. If you installed a 32 Amp model, then it is better to change it to a more powerful one, which will be 64 Amperes.

Usually, only a specialist with extensive experience in this field can calculate a breakdown. It may not test the entire system. It will be convenient for him to find the malfunction, acting step by step. When the RCD knocks out on the water heater, you need to check whether the power of the device matches the heater itself.

Tripping of the RCD in no-load conditions

Why do ouzos work without loads? In this case, the reason may be a high degree of deterioration. It is this factor that causes the occurrence of defects in the insulation of modern electrical equipment. Often this happens in the operating conditions of old washing machines and other household appliances.In almost half of all possible cases, the actions carried out with the outlet help to neutralize the consequences of the operation of the device. It is often enough to turn the plug of the device in it. In accordance with the norms of the RES, immediately after the installation of meters in apartment buildings, similar devices are also installed, with the corresponding response rates.

Important! Even if the wiring is fully functional, the protection may not turn on in time. In the event that a leak is detected, the indicators of which are in total about 100 mA, the equipment will immediately respond to this

RCD after shutdown

Finding the area where the leak occurred is the action to be taken when determining why the ouzo is knocked out. Where to begin?

• Turn off all appliances in the room
• Studying the wiring - this option should be considered if the devices are functioning properly.
• If the wiring is installed correctly, and there is no damage on it, then it becomes much easier to solve the problem of finding the right area. The same can be said about cases where the wiring is divided into several groups and has appropriate protection.
• Deactivation of machines, their restart. Start the equipment in turn. This is how it will be possible to determine the group that is not serviceable.

Important! After the "problem" group is detected, it makes sense to move on to studying the health of lighting fixtures and electrical outlets. It doesn't hurt to check the boxes too.

As practice shows, a common cause is the deformation of the insulation. Often problems are caused by illiterate installation of lighting devices, wiring.

It happens that insufficiently qualified electricians try to connect zero and ground, thus striving to provide protection against current

It is important to note that such actions are prohibited

Checking the RCD in the electrical panel

It is important to emphasize that the RCD does not perform the function of protection against short circuits. It also does not protect against overcurrents.

All that the device can do is to respond in time to the conditions in which the leak occurred.

How to provide electrical equipment with overload protection:

• Immediately after the RCD, an automatic machine with the desired rating is installed
• Equipment of a differentiated type is installed.

The differentiated type machine is a universal device. It combines the functions of a conventional machine and a residual current device.

Why does the RCD work when turned on: causes and solutions

By installing a residual current device, you can not only maintain the normal functioning of expensive equipment, but also protect yourself from getting energized. If you notice that the RCD is working, there is no need to panic, because stopping the supply of electricity in automatic mode is its main task. In this case, you should immediately find out why this is happening, and then repair the breakdown on your own or with the help of an electrician and restart the start.

How RCD works

The internal mechanism of the device is quite simple: a phase and a neutral conductor are connected to the corresponding terminals, in which the current strength is the same. But this is possible only if the device itself and the devices connected to it are in good condition. If there is a difference and it is significantly higher than the set value, then this indicates that there is a current leakage in the network.In this case, the unit is turned off.

Reasons for turning off the RCD

• There is a power outage in the mains. This can happen due to damage to the insulation with sharp objects, the end of the service life of the wiring, poor or incorrect wire connections. In this situation, the RCD is triggered when the electrical appliances are turned on.
• Incorrect placement of DVT in electrical wiring. In this situation, the tripping of the RCD will occur quite often even during normal operation of household appliances.
• Failure of electrical devices protected by RCDs. In this case, most often the reason for the operation of the device is a bad wire that is connected to the mains, or a breakdown in the household appliances themselves (usually the winding of a power unit or a water heating element).
• Incorrect installation of protective automation. When buying and connecting, you must clearly follow the instructions that come with the device. You should also study the technical characteristics of the mechanism, the principle of its operation, so that false "workings" do not occur.
• Failure of the protective mechanism itself. For example, the “Test” button has sunk or the trigger mechanism is broken, which in this case will work if even a slight vibration occurs.

If the RCD is triggered when the water heater is turned on, then this is possible:

• in case of touching the body or components of devices that are energized, as well as in case of incorrect operation of the boiler (water will not heat up);
• when changing the phase and neutral conductors, followed by touching the energized elements of electrical appliances simultaneously with touching the "ground";
• in contact with the "ground" or with another surface;
• in case of damage to the insulation of the wiring or its incorrect connection;
• during the change of zero and ground conductors.

Thus, the RCD is triggered on the water heater due to its incorrect installation or incorrect selection of technical parameters.

Why does the RCD work when the pump is turned on

There can be quite a few reasons, but basically this happens when the RCD is incorrectly connected to the pumping station, the wiring insulation is damaged, and the load on the network changes abruptly. Also, the reason may be the poor quality of the protective device. If the pump itself is faulty, the RCD trips quite often or simply does not turn on at the control panel.

How to find a problem area

• Check if the device is connected to household appliances correctly.
• If the cause is still not found, turn off all appliances powered by electricity, and then turn them on in turn (the power on the shield should work).
• If the operation occurs when the AB is turned off, then the reason usually lies in the incorrect operation of the trigger mechanism. In this case, it is better to immediately call the master.

To prevent a repeated shutdown, you need to monitor the condition of the electrical wiring, as well as all appliances located in the house

When buying an RCD, pay attention to the technical parameters of the product. In the absence of experience and certain skills in installing and repairing a residual current device, trust the master