box offsets

[garrisonm1]

Are box offsets included on the 360 degree run for conduits. what code article.

 

[celtic]

Are box offsets included on the 360 degree run for conduits.

Of course they are

what code article.

What type of pipe are you using?

 

[don_resqcapt19]

Are box offsets included on the 360 degree run for conduits. what code article.

Are they bends? All bends are included in the 360? of bends. See the xxx.26 section of the raceway articles.

There shall not be more than the equivalent of four quarter bends (360 degrees total) between pull points, for example, conduit bodies and boxes.

There are no exceptions for box offsets or other small bends. It is the total degrees of bends between pull points.
Don

 

[romeo]

box offsets

Are box offsets included on the 360 degree run for conduits. what code article.[/QUOTE

Imo an offset if made by using the 2 45 degree rule is equivalent to a 90 degree bend.

 

[LarryFine]

Be careful here. Some inspectors count any offset as a pair of 45's, which eats up one allowable 90.

 

[celtic]

What is the actual degree...say if you used a "lil' kicker"?

 

[infinity]

Be careful here. Some inspectors count any offset as a pair of 45's, which eats up one allowable 90.

Isn't that what he said?

Imo an offset if made by using the 2 45 degree rule is equivalent to a 90 degree bend.

 

[Jim W in Tampa]

Some inspectors will overlook small offsets in short runs but they all are part of the 360 if he wishes to play by the book.Who was it that came up with this stupid 360 idea ?If the run is 10 feet i bet i could get 3 #12,s thru far more than 360 in 1/2 emt

 

[dcspector]

What is the actual degree...say if you used a "lil' kicker"?

I think total would equal 10 degrees.

 

[dnem]

Then there's the other end of the spectrum, which is what we had a conversation about in our office a few weeks ago. . It wasn't the tiny box offsets we were discussing, it was the underground service supplies sweeping very long gradual sweeps thru the yard. . It's common to see 2" pipe "sprung" over a span of 100 to 150 feet.

David

 

[paul]

I have yet to seen an inspector in my area include box offsets in the total bends.

 

[dcspector]

Paul I agree. I have never included 1/2" kicks.

 

[celtic]

Who was it that came up with this stupid 360 idea ?

Whomever invented the circle :grin:

 

[Jim W in Tampa]

Whomever invented the circle :grin:

Wasn't me i only invented the square LOL

 

[Jim W in Tampa]

The 360 rule really needs to be rewritten.Often we are forced into puting in a 4 square just because we will be over our 360.When we pull them we just fish right thru that box.On 2 of the pulls we did today it proved that 360 is crazy.One had 6 90's and we fished right thru a box (on straight location).Other had on 3 90's and had to take pipe apart.Many of the runs we are doing in a parking garage simply cant be made in 360 but are short and only have 3 wires.

 

[peter d]

.Often we are forced into puting in a 4 square just because we will be over our 360.

Forced? Ummmm......yeah, every day I dread going to work because I'm forced to follow those pesky code rules. :roll:

 

[celtic]

Many of the runs we are doing in a parking garage simply cant be made in 360 but are short ....

I'm not buying that explanation

 

[Jim W in Tampa]

I'm not buying that explanation

Have you ever wired a parking garage ? It can take 80 feet of pipe and 10 bends sometimes to get from one box to the next.Really upsets me when i gotta put in a box just to solve the 360 rule when i know i can push the wire thru.

 

[winnie]

The 360 degree rule comes out of an approximation used for the calculation of pulling tension.

If you approximate your pulling tension by assuming that the conductors have no stiffness at all, is very thin, and that the conduit has no thickness, then pulling tension will increase exponentially with the total bend angle. In other words, if the tension caused by a 90 degree bend is X, then that of a total of 180 degrees of bend would be 2X, of 270 degrees would be 4X, and of 360 degrees would be 8X.

Funny, the same equations are used for brake cables on bicycles. Life is much happier when you have fewer bends in the cables

Clearly your (collective) experience shows lots of ways that this approximation falls apart. For example, the wire has certain stiffness, which means that you can _push_ it in to the first bend, which takes tension off that bend and removes the friction caused by the bend. If the pull is short enough then maybe you can push up through the _second_ bend.

Or for a small box offset, you might have a couple of 10 degree bends, but the net offset is less than the diameter of the conduit, and the conductors may feed straight in past these bends, without even seeing them.

There are probably other factors that make the approximation fall apart...however one that you may wish to consider: with small conductors in large conduit (say 3#12s in a 3/4 EMT), it may be possible to put enough tension on the conductors to damage them, yet have a low enough total tension that you experience the pull as 'easy'.

-Jon

 

[celtic]

Have you ever wired a parking garage ? It can take 80 feet of pipe and 10 bends sometimes to get from one box to the next.

At least 3 I can think of off the top of my head in the past 5 years..all in RGC - sweet!

Heavy use of LB's, round boxes offset from fixture location, condulet bodies of various configurations, etc ...all allows for compliance with xxx.26.

Really upsets me when i gotta put in a box just to solve the 360 rule when i know i can push the wire thru.

You don't have to put a box, a condulet body will suffice....or you can start a letter writing campaign to the CMP

I love that movie