When is damping cable really necessary inside rigid pipe bus? 1

[livewire9]

Any old timers or neo-gurus have some rules of thumb for when it is really necessary to provide damping cable inside rigid pipe bus? Maybe some basic rules of practice based on maximum bus span and/or diameter of pipe. I have a little intuition on this but am looking for some feedback to support or squash my thoughts.

Christopher Renedo, P.E.
ESC Engineering
Fort Collins, CO

 

[bacon4life]

How about the values on page 13-31?

http://www.aluminum.org/AM/CM/ContentDisplay.cfm?ContentFileID=57316

IEEE 605 gives some formulas as well.

 

[livewire9]

Excellent! Thanks for the pdf and the pointer to IEEE 605!