Conventional graphic designation of electric motors in the diagram

In order to draw an electrical diagram, apply conventional graphic notation of all elements. So in a simplified version, you can depict any element - a resistor, capacitor, electric motor, etc. They are standardized for the main types of elements, in this article we will consider the designations of electric motors in the diagram.

Graphic designation of electrical machines

For schematic designation, a special ESKD system was developed, according to which any engine can be displayed on the drawing. It is presented in the form of a circle, next to which a letter designation can be indicated. For example, DG is the main engine, LH is the machine spindle feed motor, DO - cooling pump, etc. Let us consider which UGOs the system standardizes; a complete list is given in GOST 2.722-68

DC motors

DC machines have a designation depending on the type of excitation. The figure shows direct current electric motor with various UGO options.

UGO of the commutator motor

In addition, there are many devices with additional features. For example, a reversible electric motor with two windings or with parallel excitation and a vibration speed controller. The following are the UGO of such devices.

UGO of direct current motors

Asynchronous machines

Induction motors are depicted in the drawings in the form of a circle, within which a smaller circle representing the rotor.

UGO asynchronous machinesThe illustration shows a graphic designation of an asynchronous squirrel-cage electric machine in a single-line circuit. For a three-phase network, the symbolic representation of a phase and squirrel-cage motor is performed in a similar way, the difference is only in the number of wires and the connection of the rotor circuit.

designation HELL with squirrel-cage and phase rotor

Moreover, if the electric motor is three-phase, the connection diagram of the windings is indicated. For example, connection a star denoted as follows:

image of blood pressure with windings connected according to the star pattern

Each type of three-phase asynchronous machine has a different view in the drawing. Below are the options for graphic designation of engines of various designs.

UGO AD of other types

Synchronous machines

Synchronous machines according to GOST are presented in the form that is indicated in the illustration below, while the scheme is easy to read even by a lay person.

The image of the synchronous motor in the diagram

An open-pole machine with an armature winding is displayed on the diagram in the form of two circles, here both the outer and the central wires are connected (to the stator and rotor, respectively).

UGO SD when connecting the windings with a triangle to a non-neutral wireIf the windings are connected by a triangle, then the synchronous motor will be depicted in the drawing in a slightly different way.

LED with windings connected according to the star pattern

The remaining varieties of UGO types of electric motors in the diagrams are presented with a description in the figure below.

Designation of synchronous machines in diagrams


The designation of three-phase generators, like synchronous motors, has the same graphic style.Below are the images that are displayed in the diagram.

Designation of generators in the diagrams

UGO of other types of electric machines

In addition to common devices, special ones are used, which also have their designation in the diagram.

UGO three-phase commutator motor

Special devices such as selsyn sensors and receivers have, in addition to the graphic designation, an alphabetic description, which is illustrated in the figure below.

Selsin on the diagram

The motor-converter has an image on the diagram in accordance with the UGO. Its outline in the diagram is shown in the illustration.

UGO of the converter motor on the diagram

Here are devices that have a collector assembly. It has an UGO in the form of two rectangles on the sides of a circle.


The graphic designation of electrical machines in the diagrams is performed in accordance with GOST 2.722. When drawing up the scheme, it is necessary to be guided by this documentation. It describes all the necessary machines, and also indicates the dimensions of the circle and other elements of the figure, which should be on the drawings and other requirements for the drawing.


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