Why do you need a contactless switch + markings and features of its connection

Innovative ideas make it possible to simplify many processes, add convenience when using household and industrial equipment, and automate work cycles.

Often, to implement them, they use a contactless switch that can respond in a timely manner to a specific stimulus without the physical presence of a person.

Let's take a closer look at what kind of device this is and what purposes it serves.

What is a proximity switch used for?

To perform a certain action, it is not necessary to take an active part yourself - go to the intended object and carry out any manipulations with it. Offered by manufacturers of electrical equipment smart product, can partially replace a person.

Operating principle of the equipment

A device that stops the functioning of certain equipment in a non-contact manner is called a switch or abbreviated as CB. It is also often called a sensor - but this concept also covers devices with an analog output signal.

Such terminology, as well as the scope of use, resistance to various types of damage and technical characteristics are provided GOST R 50030.5.2-99. The document regulates the compliance of operating parameters, timely operation of the protective mechanism during overload and other operational nuances of the device.

The product is a semiconductor element that controls an electrical circuit. When an irritant or its presence is detected in its area of ​​action, it turns off the load current, which leads to an open circuit.

The device has a durable body made of polymer or nickel-plated brass. Inside such a shell is an electrical part that needs insulation. Many models have a protection class of IP65 or 67.

The structure of the product involves the detection of an object or object that has entered the active zone. This information is converted and sent to the switching node

The device operates contactlessly, and the sensitive element, also called a photodetector, can be located separately from the emitter or in the same housing with it. These 2 parts work in pairs.

As for the size, shape and appearance of the WB, these parameters depend on the purpose and scope of application, as well as operating conditions.

The standard provides for the manufacture of devices whose body shape is as follows:

• rectangular with a square or rectangular cross-section, which is designated as D or C, respectively;
• cylindrical with thread – A or without – B.

Depending on the model and its purpose, the product may be additionally equipped with a double-insulated wire.

To work in difficult conditions, contactless devices are produced, the housing of which is filled with a compound. This is a polymer substance that provides reliable protection against moisture and other foreign matter entering the working mechanisms.

Based on the operating principle, the devices are divided into 4 broad groups.

The capacitive and inductive detection method is more reliable, and the WBs themselves, operating in this way, are more durable than their analogues. The first of them react to an object made of almost any material, and the second - to metal.

Scope of application of the contactless device

The unique property of controlling the operation of devices without contacting them directly opens up bright prospects for the use of this type of switches. It allows you to create original developments in various fields and improve living conditions in your house/apartment.

Turning off the light without the owner having contact with the housing or other elements of the switching device is a reality. For the product to execute this command, it is enough to place your hand in the affected area

And for sound modifications, it is enough to clap your hands so that the device hidden inside the chandelier body opens the electrical circuit.

In addition, non-contact sensors are widely used to optimize production processes. They allow us to control the quality of the most complex cycles in mechanical engineering.

And also on automatic lines in the production of food products and textile products, in the manufacture of parts in foundries, etc.

What does the marking say?

Contactless switches are supplied to the market by various manufacturers. Among them are Western, domestic and Chinese companies. When purchasing, it is important to pay special attention to the quality of the units and the reputation of the manufacturer.

Due to the seriousness of the regulated processes, which are controlled by various modifications of sensors, you should only choose products that have accompanying documentation - instructions with installation diagrams, operating conditions and a list of technical parameters.

On the body of the device itself, manufacturers indicate its characteristics in the form of a set of letters and numbers - they are marked. Among these designations, some of the important information is encrypted, which is used when choosing the right model.

Not all indicators can fit on a small area of ​​the switch. The rest that are important to the consumer are contained in the user manual.

If the model you like does not come with instructions, then you should not buy it - it may be a fake. Moreover, some of the necessary parameters will remain unknown, and you cannot take the seller’s word for it.

All manufacturers are required to provide technical specifications to the end consumer. This requirement is prescribed by part 5-2 of GOST on low-voltage non-contact equipment mentioned above

Each company that produces switching devices for electrical circuit control has developed its own designation system. Its decoding is given in the catalog, which also contains the range of products offered.

An example of product labeling from the company AS Energia. The remaining parameters of the models are located in the instructions supplied with the kit.

The need for marking did not arise by chance - there is a wide variety of switches. In addition, they can be classified according to various principles.

For example, depending on the function performed during switching, devices are divided into the following categories:

• switching on (NO) – A;
• shutdown (NF) – B;
• switching – C;
• programmable option – P;
• other – S.

Depending on the installation method, sensors can be recessed, non-recessed, and others.

Sometimes manufacturers prefer to indicate a long code that describes the maximum parameters of the product, including the location of the sensitive element, the presence of an indication, climate control, etc.

If the company uses the marking principle recommended by GOST, then the inscription on the switch will, for example, look like this:

U3 A30 A D2

Where:

• U – ultrasonic method of detecting an irritant. The rest correspond to other Latin letters: I – inductive, C – capacitive, D, R and T – direct, reflective and barrier photoelectric, respectively;
• 3 – installation method is different;
• A30 – shape and diameter, which in this case means cylindrical with a thread with a diameter of 30 mm;
• A – element switching function, which means switching on (NO);
• D – number of wires for direct or alternating current output, which corresponds to two connectors for direct current;
• 2 – plug-in connection method.

In total, there are 4 combination options, among which one corresponds to ribbon wires, two is considered above, three corresponds to a clamp, and four corresponds to another method.

In modifications that require the presence of a wire, the manufacturer puts the characteristics on a label that is attached directly to the cable. It may also indicate the degree of protection, recommended voltage, etc.

Among the conscientious manufacturers are ZAO Sensor/Sesor, the German company Fotoelektrik Pauly, NPK TEKO, PKF STRAUS, ZAO Meander, the companies OWEN and SKB IS, NPP PRISMA from Yekaterinburg and others.

Many of them offer the service of manufacturing VBs with the parameters required by the consumer - to order.

We also recommend reading our other article, where we described in detail the different types of light switches. Read more - read Further.

DIY connection features

You can install a contactless switch for household use yourself. As for models for controlling load current in production, installation here is allowed only to an employee who has access to specific equipment.

You should carefully consider the purchase - the switch comes with instructions, fasteners, and sometimes lock nuts. All this will be useful when connecting the device

Before connecting, please pay attention to the following points:

• the VB requires power to operate, but it cannot be connected directly if the product is a two-wire type;
• the voltage of the power source used for the contactless sensor must correspond to the parameters specified in the switch’s passport;
• When tightening fasteners, it is important not to overtighten the nuts.

The manual should have a wiring diagram to follow as well as how to install the specific model.

Installation options completely depend on the features of the purchased modification. It is important to use exactly the method specific to the purchased sensor

First, the mechanical type of installation is performed - using fasteners, if necessary, lock nuts, to connect the device.

When everything is securely fixed, then it’s time to proceed to the second stage - the electrical connection.

The wiring diagram depends on whether DC or AC current is used. The number of wires also affects the choice of circuit - here you need to be careful to correctly connect the existing cables

When working with electrical power, it is important to remember to turn off the power at apartment panelto protect yourself. Then the VB wire is connected using one of the methods provided for by GOST. Its type depends on the modification.

Most often, for domestic use, a sensor is purchased that controls the operation of the chandelier. Therefore, the last stage is placing the device in the housing of the lighting product. If necessary, adjust and configure the response time, the active distance at which the device will operate.

Assembling the device at home

You can make a switch yourself. Although at first glance, this idea seems complicated and incomprehensible to the average consumer, if desired, everything will work out if you choose a simple method.

The best part is that a person who does not have much experience in assembling electrical appliances, but is keenly interested in such units, will be able to cope with the task.

Of course, if you do not aim to create a device capable of performing programmable switching of an element, when complex response options are implemented.

The simplest option is to make a switch that detects an object at a distance of several centimeters and opens the contact at that moment. This could be controlling a light bulb, fan or other unit.

The product must be able to turn off the light bulb if the user’s hand comes within the range for a couple of seconds.

First you have to prepare the working elements for assembling the device. This will be a board, microcircuit, transistors, relays, capacitors, LEDs, photocells and other components.

After soldering, the quality of the connections made must be checked so that each structural element is securely fixed.

The service life depends on this, because the product must be placed inside the housing of a fan, hand dryer or chandelier.

It remains to check the functionality of the assembled device. To do this, carry out several response tests by holding your palm next to the sensor.

If the result is satisfactory and the design has passed the test, then it can be placed in the body of a lamp, chandelier, dryer or other equipment and connected according to the diagram

When the result obtained is not satisfactory, you have to use the adapter - an adjustment screw - to set the necessary parameters for the response.

The assembled switch can be further modified by adding the desired functions if you have experience in electrical installation work and the desire to create something original.

Conclusions and useful video on the topic

Why are non-contact switching devices needed, their types, connection and marking:

An infrared switch helps turn on the light without touching the actual keys of the switching device. Assembly and demonstration of its operation in the video:

For automatic drying, you can use a smart contactless device. About this in the video:

About capacitive type switches that operate without direct contact with an object:

Having understood the intricacies of marking and the scope of application of specific types of sensors, you can select the optimal model for switching an electrical circuit. Or even make a contactless unit with your own hands by purchasing a set of necessary elements with a diagram of their location. This switch will allow you to make your home a little smarter.

Do you want to ask a question about installing a contactless switch? Please leave comments in the block below. Here you also have the opportunity to provide an interesting fact about the topic of the article.