Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

bracing rating 1

Status
Not open for further replies.

sahelrahman

Electrical
Joined
Dec 3, 2010
Messages
25
Location
US
What is bus bracing rating?
 
Bus must be able to withstand the maximum amount short circuit current available in the given application. They must be braced to withstand that.

Good luck on your finals.

Cheers
Scott

Ps: google, over a million hits in 1.41 seconds

I really am a good egg, I'm just a little scrambled!
 
More specifically it must be braced to withstand the initial peak short circuit current. If it survives the peak when the magnetic forces are most powerful it will almost always survive the sustained short.


----------------------------------
image.php

If we learn from our mistakes I'm getting a great education!
 
There are not a general bus bracing rating as far as I know.
This need to be calculated for specific cases and design configuration.
In addition to SC, other horizontal forces should be considered (ie max. wind speed, seismic forces, etc)
Often insulators strength is the critical factor to withstand a particular loading scenario.
Check the IEEE STD 605 or similar guide for bus bracing calc.
 
Just a pedantic clarification.

Bus bracing is not to withstand the CURRENT, it's actually to withstand the MECHANICAL FORCES that will be created by the extreme magnetic field repulsion between bus bars under fault current conditions. But to the original points, it is usually expressed as a current value because the magnetic forces are pretty well understood and that's what really matters. So when a piece of gear says the "Bus Bracing = 42kA", that is saying that the insulating support structure for the bus bars will survive the mechanical repulsion forces expressed between the bus bars during a fault with a magnitude of 42,000 amperes.

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)

For the best use of Eng-Tips, please click here -> faq731-376
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top