A brief overview of the symbols used in electrical circuits

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The ability to read wiring diagrams is an important part, without which it is impossible to become a specialist in the field of electrical installation work. Every novice electrician must know how the sockets, switches, switching devices and even the electricity meter are indicated in the design of the electrical wiring in accordance with GOST.Next, we will provide the readers of the site Sam Electric with symbols in electrical circuits, both graphic and alphabetic.
  • Graphic
  • Alphabetic


As for the graphic designation of all elements used in the scheme, we will provide this overview in the form of tables in which the products will be grouped according to their intended use.

In the first table you can see how the electrical boxes, boards, cabinets and consoles on the electrical circuits are marked:

Electrical boxes, shields, cabinets on projects

The next thing you need to know is the symbol of the supply sockets and switches( including through-doors) on single-line diagrams of apartments and private houses:

Sockets on the power plan

With regard to lighting elements, lamps and lamps according to GOST specify as follows:

Components of the lighting line


In more complex circuits where electric motors are used, the following elements can be indicated:

Electric motors

It is also useful to know how graphically the transformers and chokes on the basic electrical wiring diagrams:

Transformers and chokes

Electrical appliances according to GOST have the following graphic designation in the drawings:

What do the measuring instruments look like in the drawings?

And here, by the way, is a table useful for beginners, which shows how the ground loop looks like on the electrical wiring plan, and also the power line:

Cables and Grounding

In addition, on the diagrams you can see a wavy or straight line, "+" and "-", which indicate the type of current, voltage and pulse shape:

Type of current and voltage

In more complex automation schemes, you may find incomprehensiblegraphic symbols, such as contact connections. Remember, as these devices are indicated on the electrical diagrams:

Switching devices


In addition, you should be aware of how the radio elements look on the projects( diodes, resistors, transistors, etc.):


That's all conditionally graphic designations in the electrical circuits of power circuits and lighting. As you already saw, making up a lot and remember, as indicated by everyone can only with experience. Therefore, we recommend that you keep all these tables for yourself so that when reading a house or apartment planning plan, you can immediately determine which element of the chain is in a particular location.

Interesting video on the subject:

YouTube Trailer


We have already told you how to decipher the marking of wires and cables. In single-line electrical circuits, there are also letters that make it clear what is included in the network. So, according to GOST 7624-55, the letter designation of the elements on the electrical diagrams is as follows:

  1. Current, voltage, power, resistance, time, intermediate, indicating, gas and time delay relay, respectively - RT, PH, RM, RS, РВ, РП, РУ, РГ, РТВ.
  2. CU - control button.
  3. HF - limit switch.
  4. QC - command controller.
  5. PV - limit switch.
  6. DG is the main engine.
  7. DO - engine cooling pump.
  8. DBH - the engine of rapid moves.
  9. DP - motor feeder.
  10. DS - the spindle motor.

In addition to the domestic marking of elements of radio and electrical circuits, the following letter symbols are distinguished:

Letter marking in the electrician

This concludes a brief overview of the symbols in the electrical circuits. We hope, now you know how sockets, switches, lamps and other elements of the circuit are designated in the drawings and plans of living quarters.

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