Bus Bracing Withstand Calculation

[xptpcrewx]

Wondering if anyone has any experience with bus bracing design calculations for switchgear.

I would like to know how to determine how many rigid supports would be required to withstand a particular fault current. I realize it may not be that simple of a correlation (considering the material, spacing, bus structure/arrangement).

The second part of this question is if it's even possible to infer anything about the bus bracing withstand rating solely relying on the total number or arrangement of supports or other field verifiable criteria? Any information would be helpful. Thanks in advance!

 

[jim dungar]

See if you can find an old reference, Andersonn Technical Data AEC-41. I believe its last real publication date was in the 50s, but several years ago I found a digital copy on Hubbel(?) website.

The bus bar configuration, stacked or side by side, as well as it's spacing also impacts it's SCCR.

 

[xptpcrewx]

See if you can find an old reference, Andersonn Technical Data AEC-41. I believe its last real publication date was in the 50s, but several years ago I found a digital copy on Hubbel(?) website.

The bus bar configuration, stacked or side by side, as well as it's spacing also impacts it's SCCR.

Thanks Jim, I will see if I can find it.

 

[Jraef]

Calculating is one thing, using those calculations in the every day world is another. Bracing for fault current has a lot of complex elements involved in it, all of which, after the fact, are TESTED AND VERIFIED in a destructive test. Without that, the calculations are virtually meaningless if you are building something on your own.

Here are some relevant papers from Powell Industries, I always get good insights from them.

https://www.powellind.com/sites/downloads//ProductAssets/01.4TB.023%20Using%20Design%20Tests%20to%20Qualify%20Several%20Ratings%20of%20Equipment.pdf

https://www.powellind.com/sites/downloads//ProductAssets/01.4TB.042%20Momentary%20Rating%20and%20Construction%20of%20Bus%20in%20Metal-Enclosed%20Switchgear.pdf

https://www.powellind.com/sites/downloads//ProductAssets/01.4TB.059%20Bus%20Spacings%20in%20Metal-Enclosed%20Switchgear.pdf

Also, this has been discussed here in the past. In this thread, former member Tony S (RIP) posted a formula that he was aware of at the very end.

Busbar support spacing as it relates to interrupting rating in LV AND MV applications

I'm trying to figure out what my spacing between insulator supports is supposed to be for low and medium voltage applications. The only applicable document I could find that gave me actual spacing values was UL 891 Table SB3.1 where it breaks the distances down depending on bus configuration...

forums.mikeholt.com

 

[xptpcrewx]

Calculating is one thing, using those calculations in the every day world is another. Bracing for fault current has a lot of complex elements involved in it, all of which, after the fact, are TESTED AND VERIFIED in a destructive test. Without that, the calculations are virtually meaningless if you are building something on your own.

Here are some relevant papers from Powell Industries, I always get good insights from them.

https://www.powellind.com/sites/downloads//ProductAssets/01.4TB.023%20Using%20Design%20Tests%20to%20Qualify%20Several%20Ratings%20of%20Equipment.pdf

https://www.powellind.com/sites/downloads//ProductAssets/01.4TB.042%20Momentary%20Rating%20and%20Construction%20of%20Bus%20in%20Metal-Enclosed%20Switchgear.pdf

https://www.powellind.com/sites/downloads//ProductAssets/01.4TB.059%20Bus%20Spacings%20in%20Metal-Enclosed%20Switchgear.pdf

Also, this has been discussed here in the past. In this thread, former member Tony S (RIP) posted a formula that he was aware of at the very end.

Busbar support spacing as it relates to interrupting rating in LV AND MV applications

I'm trying to figure out what my spacing between insulator supports is supposed to be for low and medium voltage applications. The only applicable document I could find that gave me actual spacing values was UL 891 Table SB3.1 where it breaks the distances down depending on bus configuration...

forums.mikeholt.com

Thanks for sharing. I am familiar with the force equations under different spacing arrangements, but what I don't know is how to apply that information to the selection and number of supports.

 

[jim dungar]

Thanks Jim, I will see if I can find it.

Note typo.
The name is Anderson Electric, it was once owned by Square D, but now it is part of Hubbell

 

[xptpcrewx]

Note typo.
The name is Anderson Electric, it was once owned by Square D, but now it is part of Hubbell

I believe this is the document you are referring to:

TECHNICAL DATA. A REFERENCE FOR The Electrical Power Industry ANDERSON POWER SYSTEMS, INC. - PDF Free Download

TECHNICAL DATA A REFERENCE FOR The Electrical Power Industry POWER SYSTEMS, INC. ANDERSON TABLE NUMBER INDEX PAGE NUMBER ANGLES 65 Aluminum Angle Conductors, Physical Properties Aluminum Angle

docplayer.net

 

[jim dungar]

I believe this is the document you are referring to:

TECHNICAL DATA. A REFERENCE FOR The Electrical Power Industry ANDERSON POWER SYSTEMS, INC. - PDF Free Download

TECHNICAL DATA A REFERENCE FOR The Electrical Power Industry POWER SYSTEMS, INC. ANDERSON TABLE NUMBER INDEX PAGE NUMBER ANGLES 65 Aluminum Angle Conductors, Physical Properties Aluminum Angle

docplayer.net

Yes.
My print copy is from before they were bought by Square D, about 60 years ago.

 

[xptpcrewx]

Yes.
My print copy is from before they were bought by Square D, about 60 years ago.

Let me know if you ever want to sell it!