Designation of markings of electric motors

Now the buyer often faces the question - how to decipher the marking of the electric motor. In Soviet times, such a question practically did not arise due to the fact that the marking of electric motors did not differ depending on the manufacturing plant and was regulated by regulatory documents.
The main types of engines were called A, A2, AO2, 4A, 4AM. Electric motors produced in the CMEA countries differed in marking, for example, in Bulgaria, instead of marking 4AM, "MO" was used and instead of 4AMN - "M".
Now many manufacturers use their markings. Below are collected the main types of brand designations of general industrial asynchronous electric motors from different manufacturers with an explanation of how to read their brand correctly.
Marking consists of several main parts:
- Brand
- Sign of modification
- Rotation axis height
- Installation dimension along the length of the bed
- Core length
- Number of poles
- Feature by purpose (constructive modification)
- Climatic performance
- Accommodation category
Let's go through each of them in more detail:
1. Electric motor brand (electric motors of all brands are the same in terms of connecting dimensions and in most cases, other things being equal, are interchangeable, i.e. if you have an ADM90L2U3 engine installed, then it can be replaced with an electric motor of the brand AD90L2U3, A90L2U3 or AIR90L2U3):
- during the Soviet Union
- since 1949 - A (IP23), JSC (IP44)
- since 1961 - A2 (IP23), AO2 (IP44)
- from 1975-1980 - 4A (IP44), 4AH (IP23), 4AM (IP44), 4AMN (IP23)
- from 1985-1995 - AIR (IP44, IP54), 5AH (IP23), 5AMN (IP23)
- currently: AIR, A, 5A, 5AM, 5AMH, AD, ADM, AIRM, (AO3, AO4 are produced by CJSC "BEMZ"):
2. A sign of modification (several designations can be used simultaneously in one brand).
C - with increased slip
E, 3E, EU - single-phase motor
B - plug-in
P - attached
M - modernized
X - with aluminum frame
K - with a phase rotor
R - with increased starting torque
Ф - with forced cooling
3. The height of the axis of rotation.
In accordance with GOST 13267, the range of heights of the axis of rotation is 50, 56, 63, 71, 80, 90, 100, 112, 132, 160, 180, 200, 225, 250, 280, 315, 355.
4. Installation dimension along the length of the bed.
Ascending: S, M, L. (from English words: Short, Medium, Long)
It is also possible that there is no designation with a single installation dimension along the length of the frame at one height of the axis of rotation.
5. The length of the core with the same installation size.
Ascending: A, B, C.
6. Number of poles (or speed).
2, 4, 6, 8, 10, 12 or in case of multi-speed motors: 2/4, 8/6/4, etc.
7. Sign by purpose (several designations can be used simultaneously in one brand).
8. Climatic version.
U, UHL, HL, T, ... - see GOST15150.
9. Accommodation category.
1, 2, 3, 4, ... - see GOST15150.
In order to order an electric motor, it is not enough to indicate the correct marking!
You must specify:
IM - mounting version
supply voltage (220/380, 380, 380/660)
IP - degree of protection (23, 44, 54, 55)