I can't find resources online describing motor frame sizes...

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I have an existing motor that has a 509S frame size, and I am not sure how different the quoted 509 frame size motor will be. All other specs appear to be the same, or close enough. Could someone describe how to decipher frame sizes, or provide a resource for this?
 

Jraef

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NEMA (National Electrical Manufacturers Assoc) publishes standard frame sizes for motors up to around 350HP (depending on several factors). Within those designated frame sizes, specific critical dimensions are supposed to be the same regardless of manufacturer.

https://www.engineeringtoolbox.com/nema-electrical-motor-frame-dimensions-d_1504.html

Above that, motors are referred to as "Above NEMA" and frame sizes mean nothing to anyone outside of a specific manufacturer. So in this case, a 509S is a designation for a Siemens "Above NEMA" motor frame size, probably Medium Voltage. Other mfrs use a "509" frame designation in their MV motors as well, but there is no official standard any longer so you can't count on anything. That's because on those large motors, they are typically made to order, so you can ask for whatever you need anyway.

https://www.industry.usa.siemens.co...cification/Documents/CZ-500-2plusPL-AF-FS.pdf
 

cad99

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NEMA (National Electrical Manufacturers Assoc) publishes standard frame sizes for motors up to around 350HP (depending on several factors). Within those designated frame sizes, specific critical dimensions are supposed to be the same regardless of manufacturer.

https://www.engineeringtoolbox.com/nema-electrical-motor-frame-dimensions-d_1504.html

Above that, motors are referred to as "Above NEMA" and frame sizes mean nothing to anyone outside of a specific manufacturer. So in this case, a 509S is a designation for a Siemens "Above NEMA" motor frame size, probably Medium Voltage. Other mfrs use a "509" frame designation in their MV motors as well, but there is no official standard any longer so you can't count on anything. That's because on those large motors, they are typically made to order, so you can ask for whatever you need anyway.

https://www.industry.usa.siemens.co...cification/Documents/CZ-500-2plusPL-AF-FS.pdf

Ok, thanks for the info, that helps. I have an existing 4kv siemens motor and I'm ordering a spare from siemens, so same manufacturer.
 
In smaller motors with which I'm familiar, an S indicates short shaft. They are often used for axial coupled hydraulic pumps, and with C-face attachments. I'm unfamiliar with the 509 frame. I see in Siemens literature, http://patricioconcha.ubb.cl/410213/siemens/nemaman.pdf that this ppears to be true. The 509S is detailed.

Thanks for the info. Looks like yes, it will have a shorter shaft. Now I just need to see if that will be an issue or not..
 

retirede

Senior Member
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Illinois
Thanks for the info. Looks like yes, it will have a shorter shaft. Now I just need to see if that will be an issue or not..

The “S” suffix in the frame size designation means “short shaft”.

If the replacement is a 509 and not 509S, the shaft will probably not be shorter.
 
The “S” suffix in the frame size designation means “short shaft”.

If the replacement is a 509 and not 509S, the shaft will probably not be shorter.


Yes, I said that incorrectly. We have a 509S onsite, and the replacement is quoted as a 509, so it will have a longer shaft. I'm working with the vendor now to see if we can get a 509S instead.
 

GeorgeB

ElectroHydraulics engineer (retired)
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Greenville SC
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Retired
Thanks for the info. Looks like yes, it will have a shorter shaft. Now I just need to see if that will be an issue or not..
Note the short shaft diameter is also smaller, 2.625" vs 4.00"

I __BELIEVE__ the short shaft versions are not designed for any side load.
 

RichB

Senior Member
Location
Tacoma, Wa
Occupation
Electrician/Electrical Inspector
didn't read thru all the posts cuz I have this ready all the time
 

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RichB

Senior Member
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Tacoma, Wa
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Electrician/Electrical Inspector
This is the NEMA chart --it is just put out by Baldor hence their advertising on it--It works across the board on NEMA motors-- or at least it has for the last 30 years for me--haven't bounced it off anyone else's charts in years--
 

retirede

Senior Member
Location
Illinois
This is the NEMA chart --it is just put out by Baldor hence their advertising on it--It works across the board on NEMA motors-- or at least it has for the last 30 years for me--haven't bounced it off anyone else's charts in years--

This thread is about a motor that is over NEMA frame size - 509. In these cases, you have get a manufacturer’s drawing.

Even within NEMA frame sizes, the ‘C’ dimension (overall length) varies by manufacturer, which may or may not be important depending on the application.
 

RichB

Senior Member
Location
Tacoma, Wa
Occupation
Electrician/Electrical Inspector
:slaphead::ashamed1:got it guys--should have read all the posts and paid better attention to the OP--My OOPS!
 
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