Probably every second MacBook owner experienced a slight tingling sensation in his fingers while touching the laptop. Does the best laptop give you an electric shock?
That is how it is. This is a widespread problem that also exists for devices of other brands.
The reason is simple: the computer case has an alternating voltage of 110V.
Why is there only half the voltage that should be in our Russian outlet? How to avoid this or try to prevent it? Let's try to answer these questions.
Where does the voltage come from on the laptop case?
Typically, unpleasant tingling sensations occur when a person touches some grounded metal surfaces.
For example, the battery radiator is under the table and at the same time keeps your hands on the metal part of the computer.
In my case it was the grounded metal edge of the tabletop. If you touched the edge of the tabletop and the MacBook at the same time, a noticeable tingling sensation appeared in your hands.
Unfortunately, this cannot be avoided, and the fault lies in the correct design of power supplies and chargers.
The fact is that there is a noise filter .
Its input is a pair of capacitors connected on one side to each of the wires of the 220V .
In this case, the housing will be connected through one of the filter capacitors to the neutral wire of the network, and through the other to the phase.
The fact is that the connection to the network occurs over 3 wires using a pair of capacitors as network noise filters.
Both are connected to the protective ground (yellow wire E), which is connected to the device body.
If there is grounding, the current from the case goes “to the ground”. If there is no grounding, the voltage on the case is half the mains voltage, i.e. 110V .
Missing grounding pin on plug
The plug assumes contact with ground on the laptop side, so the connection parameters must match. When examining the power cable with which the laptop is connected to the network, we will notice the presence of three pins: two for power (“zero” and “phase”) and grounding.
In some cases, connecting a desktop computer occurs through a surge protector. An extension cord with grounding is determined by two characteristics: the convex contacts in the socket, which are discussed in the previous paragraph, and the plug. The “ground” in the plug is the counterpart to the metal contacts of the socket, without which it will not be possible to connect the plug to the socket. To avoid overloading the extension cord, which will lead to overheating and damage, you need to ensure that the power of the devices operating on the network does not exceed the power of the extension cord. To do this, pay attention to the amperage of the devices indicated in the technical data sheet of the extension cord or in the stickers on the housing of household appliances. For example, “16A 3500W extension cord”: add up the power of the connected devices and compare with the power of the extension cord. On average, the amperage of a laptop power supply is approximately 3.5 A.
Is there a ground connection to the outlet?
Since adequate grounding throughout the entire apartment in Russia began to be laid not so long ago - previously it was found only in three-phase sockets for electric stoves and washing machines).
Therefore, there may be 3 situations with wiring in the apartment:
1. Euro sockets in which the grounding contact is connected with a neutral wire.
2. Euro sockets in which nothing is connected to the grounding contact;
3. Regular sockets without grounding.
The first option is allowed with certain reservations. At a minimum, it really allows you to relieve stress from the computer case.
In the second and third cases, the case will be connected into the void, even without a surge protector between the power supply and the outlet.
ATTENTION: the extension cord is not a surge protector and is not always equipped with one.
Surge filter for washing machine - device feature
Network filters (interference filters) are designed to suppress pulse and high-frequency interference that periodically occurs in the electrical network. The surge protector for a washing machine is designed to suppress any frequencies other than 50 Hertz.
Frequent switching of relays, starting and stopping an asynchronous motor inside the machine itself cause constant changes in currents that cannot be passed into the external electrical network so as not to damage other electrical equipment connected to it. The surge protector catches these surges and drains excess currents to ground.
Consider the electrical circuit of a surge protector:
As you can see, the washing machine power filter consists of a choke with two inductors, a resistor and three capacitors. The last two capacitors form a capacitive voltage divider, at the midpoint of which is half the mains voltage, that is, 110 V. This point is connected to the body of the washing machine, which in turn must be grounded. Grounding (grounding), in this case, in addition to protection, also serves to ensure the operation of the electrical installation.
Laptops aren't the only ones suffering
In fact, the effect can occur on any computer that is plugged into an ungrounded outlet if it has a metal keyboard frame or case.
Kettles, toasters, floor lamps, etc. behave the same way.
You can also experience such a “vibration” if you touch another person’s hand while passing under a power line, and the effect is much stronger than with electrical appliances.
When riding under power lines on a bicycle, you can feel even more vibration, even on good tires.
Of course, if the frame is made of conductive material. Steel, for example - then there is a chance that the frame capacity is enough to turn into a capacitor.
With a regular PC it’s even simpler: there is no galvanic isolation between the network filter of the computer’s power supply and the case to which a pair of protection capacitors are connected.
Reasons: why everything gives you an electric shock and 5 main recommendations
Experts believe that if almost every object in the apartment is electrocuted, it is worth calling a specialist so that he can determine what the reason is and whether a person, in particular a child, could be harmed.
In addition to the tap, current in the bathroom can include:
- Heated towel rail;
- Bathroom;
- Surface of metal objects;
- Walls;
- Boiler.
What should I do if I get an electric shock in the bathroom? It is worth noting that those who live in a private house and are faced with such a problem should first check the grounding devices. For it to be done correctly, you need a small depression in the soil cavity. A series of metal pins should be placed there, and they should look like an isosceles triangle.
Install a wire on 1 of the pins that will be responsible for the process of current drainage or for grounding.
It is necessary to attach the wire to the pin using a screw, and make sure that all electrical appliances in the house are operated exactly in accordance with the manufacturer's recommendations.
The serviceability of a water heater, washing machine or any other device is checked only when it is turned off, and we are talking about products installed in a room such as a bath. Next, the water tap opens, and the stream does not matter, and you just need to touch the water with your hand.
If the finger does not begin to tingle or tingle, this means that the equipment can receive an electric shock when it is turned on. To more accurately check the experiment, you should turn on the equipment and do the same.
Why electric shock comes from tap water: reasons
How to learn to find the place where you are receiving an electric shock? In other words, you need to examine the armored wires and find the area where current leakage occurs. For this, a special screwdriver and rubber gloves are used so that the technician is not killed by electricity. The screwdriver is called a tester. It is worth noting that if we are talking specifically about the bathroom, then it is important to remember that the sockets in this room have protection with an IP rating of 44.
To determine a leak in the bath, you need to install a device in the cavity of the distribution panel that triggers a protective shutdown with a functioning characteristic of 10 mA.
As a rule, in apartment buildings with a modern configuration, there are general and individual potential equation systems.
The essence of the system is to combine a pipeline of such plumbing equipment as:
- Sink;
- Bathroom;
- Battery;
- Toilet, even if each pipe is installed individually on each appliance, etc.
Before use, it is necessary to check the functionality of the system. It is worth noting that even if a system of excellent quality is installed, checked for faults and they are not identified, but there is still an electric shock, then you need to pay attention to your neighbors.
It is quite possible that their equipment was either installed incorrectly, or that the wires were not being used properly. Some people have no idea that it is strictly forbidden to throw wires over pipes, regardless of the purpose for which this is done, it can cause electric shock.
To be more precise, everything will be fine for the neighbor, but those who live near him will have serious problems, and even a blanket in the bedroom can give an electric shock if the bed is near a radiator with wires wrapped around it.
How to determine the cause and why the zero does not give an electric shock
If headphones or a gas pipe are electrocuted in the house, then you need to diagnose this problem. Likewise, if current starts flowing during welding, it means there are exposed wires somewhere. Initially, in order to eliminate the cause, it must be discovered.
It is much better to entrust such a process to professionals who have:
- Knowledge in this area;
- Work experience;
- A necessary tool.
For a specialist of the highest category, it will not be difficult to identify moments in the form of theft of electricity, which is often carried out by neighbors, as well as breakdowns in wires. Such a sensitive situation is detected using a special highly sensitive device, which is owned by special companies.
Diagnostics is needed in any case, regardless of which particular object in the house is experiencing electric shock, for example, a bathroom, boiler, etc.
As a rule, it includes a number of activities. The presence and correct grounding of all electrical appliances in the house is checked. External damage to the wires is detected, for which it is enough to disconnect the devices from the network and simply identify the problem area. After proper diagnosis, it should become clear why it is impossible to use the faucet in the bathtub due to constant electric shocks.
What to do if the boiler electrocutes through water
If there are problems with electric current passing through the water, you must first check the sockets to which the appliances in the room are connected. To do this, phase and zero are examined, but the problem is predominantly present in the zero region.
It is worth noting that if a current leak is detected in a room, this does not mean that if the defect is eliminated, it will not occur again.
To exclude this, you need to familiarize yourself with a number of preventive safety measures when operating electrical appliances. An RCD or a residual current device for a differential circuit breaker is installed in an apartment or access switchboard. They are mainly mounted on units that are most susceptible to electric shocks.
Recommendations:
- An incoming protective device is installed in the distribution panel, through which safety is ensured if the RCD fails.
- A protective grounding must be installed in the electrical power supply network.
As already noted, when using water in the bath, electric shock is possible if the neighbors were negligent. All this is due to the fact that it was the pipeline that began to be used as a grounding conductor, which is strictly prohibited by law.
If you get an electric shock in the bathroom: safety measures in the room
Electrical wiring in a room with high humidity is already a great danger, and therefore care must be taken to minimize the likelihood of problems occurring.
Experts recommend installing special covers on:
- Sockets;
- Switches;
- Lighting fixtures, etc.
If there is even a minimal probability of water penetrating inside the cavity of the socket, then this becomes the cause of current leakage; accordingly, if you touch the wall, a tingling sensation occurs. Unfortunately, if the problems are not corrected, you can even get a severe electric shock, which may require medical help.
To prevent such situations, craftsmen recommend using plug-in designs, since such electrical devices have reliable protection against moisture penetration inside.
To ensure a 100% safety guarantee, you must first buy high-quality devices operating from the network and check that their technical characteristics coincide with the actual performance. In addition, when purchasing devices, you need to inspect their tightness and reliability of insulation.
Despite this, the housing protection must be present, and if it is missing, then it must be installed independently. When laying electrical wiring, the equipment is installed in such a way that the switch is not close to the bathroom.
The installation of the distribution box is carried out where there is no humidity, and the box itself must be completely sealed.
How to give an electric shock (video)
There may be several sources of current loss in the room, and these are warm electric floors, damage to the residential structures of heating cables, and violation of the integrity of the insulation of heating equipment wires. If the cause of the current is the underfloor heating system, then it is either repaired or completely abandoned.
Source: https://6watt.ru/elektrooborudovanie/pochemu-bet-tokom-ot-vsego/
Why do Apple laptops give electric shocks?
In buildings with modern wiring, where outlets are properly grounded, Apple equipment continues to electrocute.
It's all about the features of Apple power supplies. More precisely, in a removable fork, which is a great help when traveling.
The kit always includes a short plug in the body and a long plug on the wire.
European , American and Chinese short plugs without grounding contact.
The British one has a grounding plug, but no contact.
The required contact is only in the extended plug, which can be checked by looking at the place where the plug attachment is attached to the power supply: there should be contacts for the grounding washer inside.
If they are not there, the laptop is guaranteed to receive an electric shock. Counterfeit blocks will definitely hit even with an extended socket.
Methods of protection
Since in practice it is impossible to completely eliminate all factors of insulation failure and potential transfer to the device body, it is much easier to protect yourself and your loved ones by installing additional means.
Grounding
According to the requirements of clause 1.7.51 of the PUE, all electrical devices connected to the network must have a protective grounding of the housing. This grounding has a separate terminal, both on the plug of the device itself and on the socket. All modern washing machines are equipped with such grounding from the factory. And if you connect to the ground wire, in addition to the washing machine, other metal elements surrounding it, you can create a potential equalization system.
Figure 2: what is connected to the potential equalization system
The only stumbling block to providing protective grounding to household consumers in an apartment is the lack of a protective wire in the general system of the entire house. Old Soviet buildings were indeed designed without them, but they are gradually being converted to safer ones. The situation is much simpler for owners of private houses, since in your home you can always install a grounding loop yourself and connect the grounding to the distribution panel.
To connect the grounding, at the stage of laying the wiring, it is necessary to install an additional protective wire from the electrical panel to each socket. This will remove the potential from the device body and redirect it to ground. Therefore, instead of accumulating on the body of the washer, it will flow to the ground along the electrical circuit created by the protective ground.
If this is a current of natural origin, due to the imperfection of the internal insulation of the washing machine, it does not pose a danger to humans, since its magnitude is quite small. If the leakage current from the housing exceeds 10 mA, which is dangerous for humans, then it is worth eliminating the possibility of injury and installing an RCD in the grounding wire circuit.
RCD installation
Unlike standard household consumers (kettles, vacuum cleaners and refrigerators), the washing machine is located in a particularly dangerous room, where there is high humidity and conductive structures. Because of this, it is unsafe to use only machine guns as protective devices. A standard circuit breaker is designed to respond to a significant increase in current that is possible during a short circuit. And in the case when the washing machine receives an electric current, the amperage to turn off the circuit breaker is insufficient.
Figure 3: connecting the washing machine via an RCD
The problem can be solved by installing an RCD in the power supply circuit of the washing machine, which reacts to the current in the grounding conductor; its installation is regulated by clause 7.1.48 of the PUE. To protect the washing machine, models with a cut-off current of 30 and 10 mA are suitable. The second option is the safest, since it will turn off the device with the least signs of an accident. A 30mA RCD is suitable for situations where the washing machine is quite old or is operating in a sufficiently damp room, which is why its normal operating condition exceeds the threshold for more sensitive protection.
Why doesn't Apple do anything?
This behavior of laptops has been recorded for a very long time. But nothing has changed, either in the approach of Apple or other brands. The thing is... everything is fine.
Each electrical device, receiving sales certificates for a specific country, undergoes adaptation and testing in the electrical circuits of that country.
For Russia, laptops and Apple equipment in particular are subject to certification according to
- GOST IEC 60950-1-2014 “Information technology equipment. Safety requirements",
- GOST R IEC 60950-2002 “Safety of information technology equipment”,
- GOST R IEC 536–94 “Classification of electrical and electronic equipment according to the method of protection against electric shock.”
According to these documents, the MacBook is an electrical equipment of protection class I and category “Current-limiting circuit” , which means
...A circuit designed and protected so that the current flowing in it, both under normal conditions and under single fault conditions, does not reach a dangerous value. Safety is ensured by basic insulation and the connection of exposed conductive parts accessible to touch with the protective conductor of the fixed wiring. Do not operate on networks that do not provide connectivity...
Therefore, MacBook power supplies with a three-prong plug are NOT DESIGNED to operate without a ground connection!
However, if you look at the instructions, this is written there. But who reads them?
Headphones are used
Using wired headphones in a network-connected device can lead to disastrous results. In power supplies there is a significant probability of long-term electrical breakdown. A network current of 0.5 A, with a voltage of 220V, enters the low-voltage circuit, and this in turn leads to damage to the user through the headphones.
The reason may be the use of a third-party power supply or an accidental lightning discharge, which greatly increases the voltage and current in the network. Do not use headphones when the device is plugged in, or switch to a wireless analogue that uses Bluetooth technology. When the computer is running offline from a battery, using wired headphones is safe.
How dangerous is this for humans?
It is difficult to predict possible problems along the ground line.
If the circuitry of the computer's power supply or charger is of sufficient quality, and there are no obvious violations in the wiring, the “tickle” is harmless to both humans and the computer.
It's not volts that destroy people, it's amps that destroy people.
It is unlikely for a person to get seriously injured in this way: the currents are not the same. Especially if the power supply is of high quality and connected through an extension cord with a high-quality filter.
But if the design does not provide for grounding, it is better to accept what is happening.
Why does everything give me an electric shock: what is the reason?
We can safely say that every person, to one degree or another, has experienced an electric discharge. Not only an electrical appliance, but also a person can receive an electric shock. Bioelectric impulses appear when life begins and disappear with the onset of death. Let's consider how contact with electricity affects a person and how to avoid it.
Reasons why electric shock occurs
There are people who are often shocked by everything. What is the reason for this phenomenon is sometimes completely unclear. Obviously, an electric shock can be obtained by touching an object under voltage above 36 V. In this case, a short circuit occurs through the body, resulting in an electric shock.
But a person receives a release from things that are far from tension.
The reason why everything gets electric is static electricity. It occurs when charges accumulate on the surface of physical bodies that do not conduct electricity well.
They persist for some time, then a discharge occurs, causing discomfort.
Electrostatic charges arise as a result of friction, so they accumulate faster in winter, when the air becomes drier and a person wears wool, fur and synthetic clothing.
Why does a person get electrocuted?
We can say that a person is a kind of electrical system, so he receives an electric shock when there is a large accumulation of electrical charges. This happens for two reasons:
- The body, like a mini-power plant, produces its own electrical currents .
They are not felt by humans, and can only be measured with ultra-sensitive instruments. Part of the biocurrents is used to maintain the vital functions of the body, and the excess is converted into static energy. - Input of static electricity from outside .
An electric charge, positive or negative, can accumulate on the surface of any substance (the so-called triboelectric effect). Electrification occurs when objects are heated or cooled, irradiated by energy sources, when a frictional force acts on them. Synthetics, fur, wool, and hair are especially strongly electrified (but cotton fabrics, wood, and glass are not “charged”).
The human body is well electrified. This is facilitated by the lack of grounding, wearing clothes and the fact that his skin is covered with hairs. When a person touches an "uncharged" person with a hand or other part of the body, a discharge occurs, which is manifested by a crackling or tingling sensation. Often bioelectricity of great power hits its owner painfully: he gets an electric shock from everything he touches.
Why doesn't every person get an electric shock?
Each person accumulates a different amount of electrostatic charges because they have individual resistance and electrical capacity (the ability to accumulate electricity). There is a theory according to which the amount of biocurrents produced also depends on the psycho-emotional state.
High static voltage in humans is a phenomenon that scientists still cannot solve. Such people (there are not many of them, they have lived at all times) can withstand mains voltage of 220 V and higher, so they calmly pick up wires with their bare hands.
Their body can be used as a conductor to light a light bulb, but touching a carrier of extreme bioelectricity is dangerous.
Why does water beat with electric current?
Water is a conductor of electricity, so if electrical wiring and plumbing cross paths, you may feel an electric shock when washing your hands from the tap.
The reason for this phenomenon may be the following:
- lack of proper grounding in the apartment;
- damaged insulation of bathroom electrical wiring;
- damage to the apartment's electrical network;
- installation of sockets, switches, lamps not intended for use in damp areas;
- use of water pipes for grounding;
- breakdown of the heating element in the boiler, water heater, washing machine;
- an ungrounded electric stove or dishwasher located in the kitchen near the sink.
The problem can be caused by neighbors who connect the neutral wire to the water pipe, stealing electricity. You can check this by turning off the power to your apartment: if the water is electric, then the cause is from outside.
How to remove static electricity
In everyday life, static electricity creates many unpleasant moments, so let’s look at a few recommendations that will tell you what to do to remove the increased charge:
- Wear underwear made of cotton fabrics.
- Add conditioner to rinse clothes after washing.
- Use special products (“antistatic agents”) for clothes made of synthetics, silk, wool and carpets.
- Do not use plastic, but wooden or metal combs.
- Attach a metal pin to the garment from the inside out.
- Walk barefoot on a wooden floor, or on the ground in summer.
- Wear antistatic wrist straps when working with electrical appliances.
One of the ways that effectively removes static electricity is humidification. The static charge caused by contact with synthetic clothing will decrease by 1.5 times if the air is humidified from 40 to 60%. For this purpose, special devices are used and the room is ventilated more often. A good effect is achieved by laying a damp towel on the radiators.
To remove static electricity from the car body, antistatic belts in contact with the road are used, and in modern cars special devices are built in for this purpose. The apartment uses a special potential equalization system, which is combined with the ground loop.
To quickly remove an electrostatic charge from yourself, you need to touch any grounded metal with a metal object.
It is impossible to avoid contact with electrical charges; they surround a person everywhere and are inside him. Biocurrents, small in power, do not cause harm to life and health. But regular exposure to them can cause malfunctions in the body and lead to death. Therefore, you need to regularly get rid of static electricity.
Source: https://pauk.top/bet-tokom-ot-vsego-v-chem-prichina.html
Options for solving the problem
There is no really working way to solve the problem in Russian conditions. Need grounding.
Life hack: sometimes it is enough to re-plug the power supply plug to change the phase and zero. But not always.
You can try to make sockets with grounding, and not just suspend the third contact in the air. And charge your laptop only at home, fortunately, autonomy today will allow many to do this.
But here’s the problem: if there is no full grounding through the shield, it’s better to forget about it.
Of course, you can “zero the ground” by combining the “ground” wire with the “zero”-neutral contact.
If you connect it directly to the outlet, catching a short circuit is as easy as shelling pears.
If you do it in the shield, if the zero is accidentally broken, there will be a phase on all cases. And the devices will burn out, and there will be dangerous parameters that can lead to death.
Electricians may also suggest connecting the ground to the battery or pipes. Strictly prohibited up to a criminal sentence!
The method worked in ancient times, when all risers were assembled from metal and led directly into the ground under the house.
Nowadays, steel pipes are often replaced with plastic ones, so grounding will not work - the connection between the battery riser and the ground (basement floor) is simply broken.
If someone throws a ground there or a short circuit occurs, a strong electric shock will occur.
It might even kill someone. But even if not, such a connection is now criminally punishable.
A washing machine is electrocuted without grounding - modeling situations
Now let's simulate situations with a washing machine. First, let's connect it to the network and look at the potential difference between the housing and the conductive communication element connected to the ground (pipe, tap, battery). Since the washing machine is connected without grounding or grounding, the voltmeter will show a potential difference of 110 Volts.
What will happen to a person if he simultaneously touches a metal pipe and a section of the washing machine body that damages the paint layer? A current of 1.75 mA will pass through the human body, causing itching and slight tingling of the skin, and severe trembling of the fingers.
Now let’s connect the body of the washing machine to a grounding electrode with a very high resistance of 100 Ohms. In this case we get the TT system. As a result, the current passing through a person was significantly reduced to 0.16 mA, which is quite safe. Therefore, for normal protection it is not necessary to make ideal grounding with a grounding device resistance of about 4 ohms.
Now let's consider the situation with zeroing - the TN-CS or TN-S system. In this case, even less current, 0.03 mA, will pass through the person.
As you can see, despite the fact that the washing machine operates without grounding, this protection should not be neglected. But, as mentioned earlier, many simply physically do not have the opportunity to do either grounding or grounding. And an RCD without grounding, although not ideal for phase breakdown on the housing, does not solve the problem of the network filter.
