Conductor support

[Rick 0920]

How many conductor supports would I need for a vertical run of rigid conduit installed to a height of 250'. The conduit has (4) #500 MCM copper conductors installed?

 

[wwhitney]

Table 300.19(A) says that for copper conductors, over 350 kcmil through 500 kcmil copper conductors may be unsupported for up to 50 feet, but no more.

So if your height is exactly 250', and if you can place the conductor supports at exactly 50' intervals, you will need 5 supports per conductor. If the height is slightly over 250', or if there's an obstruction at one of those locations so you can't get the support at the exact optimal location, it will end up being 6 supports per conductor.

Cheers, Wayne