NEMA and IEC standards for electric machines 1

[Clyde38]

I would like to know what NEMA and IEC standards I need to have to make sure that an electric motor conforms to NEMA's and IEC’s standards. I am most interested in how to determine the dimensions that the motor will have to conform to and what tests it must comply with. I see reference charts with several dimensions for various frame sizes but items such as the terminal box for instance are not completely defined. Also, the “C” or "L" dimension (overall length) states "contact your local office" for this dimension. I’m also interested in knowing which documents cover the requirements for IE3 and IE4 ratings (or Premium and Super Premium).

I am looking to purchase these documents for my reference, so I'd like to know which ones are pertinent to electric machines so that I may order them from the perspective agencies. A list of documents for both NEMA and IEC is what I'm looking for (if indeed there is a list). I have seen condensed versions of NEMA MG1 and draft versions of IEC 60034-30 but I don't know if these two documents are enough for me to properly design and build machines that conform to both the NEMA and IEC standards.

 

[7anoter4]

I was electrical machines designer in 70’s.I don’t think the design process is changed so much.
No standard will give you a “calculation way”. The dimensions and the details as
magnetic [iron] circuit and windings calculation you have to search in books-if you did not learned it in college. The manufacturer experience is very important also.
The standard will state the tests and the required performances.
I cannot recommend you a machine designing book since the material I used 40 years ago are not the same a good manufacturer use now.

 

[Clyde38]

Thanks 7anoter4,

I don't need calculation methods. I need to know the acceptable construction, mounting arrangements, terminal box position, etc. These items have been set forth in the applicable standards and in order to comply to them I need to have a valid document to use as a reference. Up until now I've been using the published documents provided by manufacturers such as Baldor, WEG, Nidec, etc. I'm sure that the dimensions they provide conform to the NEMA and IEC standards, but I would like to have the actual standard for reference. I would also like to know what documents (both NEMA and IEC) cover the performance requirement relative to both standards. I realize that the standards are very similar, but there are minor differences in dimensions and ratings. So far I have been able to find NEMA MG1 - 2011 and IEC 60034-7. Are these the only documents required?

 

[Clyde38]

Here is an example. The maximum length for the NEMA frame motor (single shaft) is dimension "C". I can't find any dimension for that length in the condensed MG1 that I have. I don't have a "condensed IEC standard, but the same dimension is labeled "L" for IEC frames. This information is taken from a Baldor quick reference chart. In both cases, the reference chart states "Contact you local Baldor office for "L" (or "C") dimensions".

 

[7anoter4]

There are some dimensions included in standards-in order to assure interchangeability-as shaft height, bolt distances, driving axe diameter and length and so on. But other dimensions are up to manufacturer depending on material quality and prices.
For IEC world the frame standards are:
IEC 60072-1:1991, Dimensions and output series for rotating electrical machines – Frame
numbers 56 to 400 and flange numbers 55 to 1 080.
IEC 60072-2:1990, Dimensions and output series for rotating electrical machines – Part 2:
Frame numbers 355 to 1 000 and flange numbers 1 180 to 2 360.
In USA MG-1 Standard in Section I GENERAL STANDARD APPLYING TO ALL MACHINES
Part 4 DIMENSIONS,TOLERANCES AND MOUNTING.

 

[Clyde38]

Thanks again 7anoter4,

I have spent almost two days on the phone to the various agencies (NEMA, IEC, and ANSI) and I was not able to get this information.