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#212657 01/30/14 12:00 PM
Joined: Jul 2004
Posts: 136
C
cgw Offline OP
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For a conduit installed for data cable (e.g. conduit from wall box up to above ceiling) - What should the minimum radius of the elbow be?

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Joined: Mar 2004
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W
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4 times the diameter of the cable is the min, for regular bends 50mm is the min.

Joined: Jun 2004
Posts: 1,273
T
Member
Radius in such situations is almost never an issue.

The crippler is the size of the conduit.

Typical minimum for trivial need: 3/4"

Robust data-com spec out 1 1/4" drops -- for which j-boxes are in mass production (yet special order from your distributor -- such big KOs have to be spec'd) (4-11s)

It's not uncommon for the drops to have no elbow at all. Instead, the drop is a sleeve capped by a plastic bushing -- typically a white nylon style -- Arlington pitches theirs all the time in EC Magazine.

It's common for the spec's to call out for bushed entries, BTW. Bare pipe won't do.

%%%%

Eriksen sells a bender that kicks out mild sweeps in EMT.

It's popular in the data-com world, too.

http://www.ericksenbender.net/

This is usually a company tool. Its sweeps are so gentle that it's possible to go to down a size for data-com sweeps. (ie, 1" replaces 1 1/4") If you do this often enough, then the bender pays for itself.

[ Note: downsizing data-com drops is only possible if you've got the data-com contract. In all other cases, you're in the blind -- and will have to follow the contract spec's. These are usually worked up on the most conservative (oversized) basis so that the writer doesn't get bit by final results.]

%%%

In all cases, never attempt to get away with 1/2" EMT.

%%%


Last edited by Tesla; 01/30/14 06:17 PM.

Tesla

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