Magnetic locks on the door: choice, principle of operation and installation

In the 21st century, electronics displaces mechanics in almost all spheres of human activity, including locking devices for entrance and interior doors. Almost every entrance in major cities today is equipped with an intercom with an electromagnetic lock, and in office centers there are magnetic locks on the interior doors that allow you to restrict the access of different personnel categories to different rooms. Therefore, it is worth understanding what the principle of magnetic locks on the door is, how they are installed, how to make the right choice of such a device.

Magnetic constipation is now common in households, as well as in commercial buildings and government offices. It is these locks that are placed on the entrance doors of the entrances, along with intercoms, so that residents have the opportunity to open them remotely. In office centers, the installation of such locks allows you to give different employees access to different rooms - an access card can open only one lock or several at once. Moreover, in the event of an employee being dismissed, it is not even necessary to take the key from him - it is enough to change the access signature and update the cards of the remaining employees.

Finally, in state institutions such locks are installed on the premises in which especially valuable items or documentation are stored, since these devices are usually much more reliable than mechanical ones. At the entrance doors of individual apartments and private houses (with the exception of elite cottages) magnetic closures are so far extremely rare. There are almost no electromagnetic locks on the interior doors of residential buildings. But simple magnetic latches in such cases are widely used since Soviet times.

Both for serious electromagnetic devices with cards or keys, and for primitive latches, the principle of operation is based on the mutual attraction of parts with different magnetic charges. In the case of a latch, two permanent magnets are sufficiently oriented so that their opposite poles are opposite each other. The action of electromagnetic locks is based on the appearance of a magnetic field around a conductor through which alternating electric current flows.

If you give the conductor the shape of a coil, and inside it you put a part made of ferromagnetic material (which is called a core), then the magnetic field created by such a device will be comparable to the characteristics of powerful natural magnets. A working electromagnet, like a permanent one, will attract ferromagnetic materials to itself, including most conventional steels. Expressed in kilograms of effort required to open doors, this force can be from several tens of kg to one ton.

Most modern magnetic locks are an electromagnet with a control system. and the so-called counterplate, usually made of steel. In the closed state, an electric current constantly flows through the system. To open such a lock, you need to temporarily stop the supply of current to it. This is achieved using a control system, which usually includes a special readout unit that receives data from a magnetic key, tablet or plastic card and compares it with the data stored in its own internal memory. When the signatures match, the control unit shuts off the current, and the force holding the door disappears.

Often, such systems include additional elements, the most common among which is a pneumatic closer, gradually returning the door to a closed state. Sometimes there are combined variations of magnetic locks with mechanical ones, in which the forces of magnetism are used to hold a moving part (known as a bolt) inside the corresponding groove. These structures are devoid of the advantages of electromagnetic and represent an advanced version of the latch, therefore, they are used only for interior doors in homes and offices.

As mentioned above, according to the principle of the magnetic locks are divided into:

• electromagnetic;
• using permanent magnets.

In turn, according to the method of opening the electronic magnetic lock on the door can be:

• by keys;
• on pills (kind of magnetic keys);
• on the card (the signature is recorded on a plastic card, which is read by a special device);
• code (control device includes a keyboard, providing the possibility of entering a code);
• combined (such stand on most intercoms, the door can be opened either by entering a code or using a tablet).

Moreover, if in most cases the data of the key, tablet or code is compared with the data from the internal memory of the device, then the models with card access are usually connected to centralized control systems. In this case, each card has its own code that uniquely identifies its owner. When reading a card, this information is transmitted to the central server, which compares the cardholder's access rights with the security level of the door he is trying to open, and decides whether to open the door, leave it closed or even raise an alarm.

Locks on permanent magnets are opened in any case by mechanically disconnecting the two parts. In this case, the input force must exceed the force of magnetic attraction. If conventional latches are easily opened using human muscular strength, then in the case of combined mechanical-magnetic locks, opening systems are sometimes used using force-enhancing levers. By the way of mounting the door magnetic lock can be:

• overhead, when it is mounted on the outer part of the door leaf and the outer part of the door frame;
• mortise, when both parts are hidden inside the canvas and the box;
• half-cut when part of the structural elements is inside and part is outside.

All magnetic locking systems have common advantages:

• minimum number of moving parts (especially the absence of a locking spring)significantly increases the durability of the castle;
• minimum external wear during operation;
• ease of closure;
• closing and opening of the door is almost silent.

Electromagnetic options additionally have the following advantages:

• integration with centralized security and surveillance systems;
• making copies of a magnetic key is much more complicated and expensive than usual, which reduces the risk of entry by unauthorized persons;
• a huge locking force, far surpassing the capabilities of most mechanical systems;
• Due to the large dimensions of the counterplate, the occurrence of a skew of the doors during operation almost does not reduce the locking efficiency.

The main disadvantages of electronic systems:

• some old intercom systems with a code lock have a universal service access code that may be known to intruders;
• for the stable operation of the system, constant power supply is necessary, since without the flow of current the door will be in the open state;
• the complexity of installation and maintenance (change signatures of access, repairs, etc.);
• reliable electronic constipation so far is much more expensive than the mechanical counterpart.

Systems based on permanent magnets have the following advantages:

• work without current source;
• easy installation

The scope of delivery of the electromagnetic locking system most often include:

• electromagnet;
• mating plate made of steel or other ferromagnetic material;
• control system;
• accessories kit for system installation;
• wires and other switching devices.

Depending on the type of device, they are additionally supplied with such means for opening:

• with a card or a set of them;
• with pills;
• with keys;
• even a remote control kit is possible.

Optionally, the package may include:

• air guide;
• a bespereboynik providing temporary system operation without external power supply;
• intercom;
• external interface controller providing integration with the security system.

The magnetic snaps usually include:

• two latch elements mounted on the door and the box;
• fasteners (usually screws).

Combined mechanical magnetic locks are supplied in this kit:

• lock with lever (deadbolt);
• mate with the corresponding bolt hole to be installed in the box;
• fixture and accessories.

Additionally, these devices can be equipped with:

• pen;
• clamps;
• magnetic card and its reading system.

When choosing a type of magnetic lock, it is worth deciding for which room you want to use it. Primitive latches or mechanical-magnetic locks will be enough for the doors between the rooms of the apartment, it is better to use an electromagnet with a tablet and intercom for the entrance doors of the entrance, the option with a remote control is ideal for a garage or a shed door.

For office centers, a system with electromagnetic locks, maps, and centralized management is virtually no alternative — otherwise, each employee will need to be given a set of separate keys. When choosing an electromagnetic device, take into account the locking force - installing a lock with an opening force of one hundred kilograms on a thin door can lead to its deformation or even breakage. On the contrary, a weak magnet is unlikely to hold a massive metal door.

• for interior and interior doors enough effort up to 300 kg;
• for entrance doors fit constipation with a force of up to 500 kg;
• for armored and massive iron doors, locks are suitable with a margin of up to a ton.

Put the magnetic latch on a wooden door is quite simple - you just need to mark the canvas and the box and attach both parts with screws. Kombi-locks are put as usual mechanical. But the installation of electromagnetic systems is best left to professionals. To install a magnetic lock on a glass door, you need to purchase a special fastener, which usually has a U-shape. It is installed without drilling the glass sheet - it is firmly held by a system of screws, clamps and softening pads.

How to install a magnetic lock on the door, see the next video.