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 .
Laptop shakes and shocks due to static electricity
First we need to clarify what electricity is, in principle. This is the movement of negatively charged particles, electrons, between atoms. Their constant movement is called electric current, which powers household appliances in your home and charges mobile gadgets. Static electricity is different - it does not flow, but accumulates. This phenomenon occurs because the electrons of some atoms are attracted to others. This usually occurs when various materials or substances rub against each other. Those particles whose attraction is stronger take electrons from those that are weaker. This upsets the balance.
Static electricity can also build up on your hands - this is especially true if they are very dry | ProStorage
Static electricity can build up on clothing. Synthetic fabrics and wool are especially fond of collecting charges, but all materials can do this to one degree or another. When they rub, they receive charges - either negative or positive. The plastic and metal that laptops are mostly made of are no exception. Therefore, static electricity easily accumulates on the device’s body. Charge can also accumulate as a result of interaction with the electrical network. In any case, if the electricity has nowhere to go, sooner or later a discharge will occur when you touch the gadget.
Getting a discharge of static electricity from a laptop when working with it on your lap increases significantly | Technorocks
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.
Signs and solutions
It should be noted that for any breakdown of the washing machine that occurs, before repairing it, it is necessary to turn off the electricity and completely de-energize the device.
| Signs | Breaking | Remedy |
| Gives an electric shock when not working. | Socket contact problem | remove the plug contacts from the socket, restore the connection unit or replace damaged elements |
| The insulation of the wires or power cord is broken | test the cord and internal insulation, replace damaged electrical wiring. | |
| The power button or control unit has a short, causing voltage to occur on the metal case. | It is necessary to disassemble the front panel of the washing machine and eliminate the malfunction of the button or the entire unit; if repair is impractical, they can be replaced completely. | |
| The power filter is faulty | Disassemble the filter itself and eliminate the breakdown in it. If this is not possible, replace it with a new one. | |
| The machine is constantly damp, which causes condensation to accumulate, which conducts voltage from the electrical supply circuit to the body. | To eliminate such a malfunction, it is necessary to change the operating conditions or purchase a washing machine with a higher moisture resistance class. | |
| The body receives an electric current only during washing, the water does not heat up or does not heat up well | A broken heating element is the most common failure; the current value depends on a number of factors, which can lead to damage or slight tingling. | Disassemble the washing machine, remove the damaged heating element and install a new one. |
| Electrocutes only during washing. (the machine may not start) | The insulation is broken or the motor has broken down. | The device is also disassembled, the engine is removed and a new one is installed. In most cases, it is not practical to repair a burnt-out engine. |
| Electric shock hits the floor near the washing machine | Water leakage and damage to the wire, which created the conditions for an electric shock. | Locate the contact point (wire or housing), restore the insulation and eliminate water leakage. |
It should be noted that if the need arises to disassemble the washing machine, it is better to acquire an electrical circuit for a specific model. This will greatly simplify the task and help avoid damage to the washing machine due to your own carelessness.
If you already have three-wire wiring installed in your house, which includes zero, phase and grounding, be sure to check the integrity of the grounding conductor itself. To do this, use a regular tester or control. First turn off the electricity at the input circuit breaker.
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.
Can a laptop be damaged by static electricity?
With normal use, the chance of damaging your laptop with static electricity is close to zero. The discharge will pass through the body of the device or through the user’s body. The likelihood that the inside of the device will be affected is extremely low. The danger increases if the discharge occurs while touching the device port. In this case, it may not go through the laptop body, but through its internal components. In this case, everything very much depends on the force of the blow. Unless you deliberately try to damage the motherboard and everything else, the chance of this happening is very small.
To avoid damaging the inside of your computer with static electricity, it is better not to touch its ports again | Promotional Drives
There is a much greater chance of damage to the laptop when opening it for cleaning or repair. A discharge of static electricity can have a voltage of tens of thousands of volts - due to the low current strength, it is not dangerous for humans, but it can easily burn sensitive electronics. That is why it is important to use special antistatic bracelets when making repairs or any other manipulations. In self-respecting computer services, this is a mandatory rule that should not be neglected at home. Such bracelets are connected to a grounding point and ground the person himself.
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.
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?
High humidity
Using electrical appliances in conditions of high humidity always involves danger. In an apartment, such a place is the bathroom, where the highest humidity is observed. Unfortunately, the standard network grounding system does not protect against short circuits when water enters, because moisture becomes the main conductor of electricity. For this reason, you must be extremely careful when operating your laptop, avoiding even the slightest contact with water.
In addition, an important point is the technical characteristics, reliability, level of protection and quality of installation of the outlet. It is acceptable if the degree of protection of the socket is not lower than “IP54” - splash-proof. It would not be amiss to install a separate protective shutdown system in the apartment electrical panel for the power line leading to the bathroom.
Usually people don’t think about the fact that using such a common household item as a laptop can lead to such disastrous consequences. Using simple observations and methods outlined in this material, you can determine the level of security of the power network, starting with the device itself and ending with the room in which it operates.
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.
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.
Grounding the washing machine
In modern houses, grounding is mandatory in accordance with new standards. Machines produced by manufacturers are also equipped with a three-wire cord (ground, phase, zero). A completely different situation arises in apartments built during the USSR. There were no requirements for mandatory grounding then, and the number of electrical appliances in apartments was small.
The problem of lack of grounding can be solved in two ways.
- Equip an outlet in the apartment with access to the panel. If there is a grounding connection on the housing next to the meter, you can invite a specialist or leave a request at the Housing Office for the installation of a separate outlet, the power of which will be supplied directly from the panel. In this case, the two-wire wiring is changed to a three-wire cable with grounding and a separate circuit breaker is installed on it.
- Set the RCD (residual current device) to 10 or 30 mA. The device will turn off the power on the panel even with a slight leak, regardless of the cause of the breakdown. It should be taken into account that in old houses the RCD may be triggered regularly and the owner will have to constantly turn on the machine when entering the stairwell. In this case, an alternative can be an outlet with a built-in RCD into which the washing machine will be connected.
A working machine can receive an electric shock even if it is grounded. The reason may lie in the wear of the wiring leading to the shield.
