Is 90 degrees the maximum bend?

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George Stolz

George Stolz

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A question came up at work, and I promised to ask on the forum.

Can a single bend in EMT legally exceed 90 degrees? Everyone was aware that a run of EMT could not exceed 360 degrees between pull points, but can a single bend in that run exceed 90 degrees?

Many believe it cannot. Thanks for all replies. :)
 
We call it a Shepard hook and it is ugly but we occasionally use it when we have stubs sticking out of walls.

IMO it does not violate the NEC.

If going over 90 at one bend is a violation so would be going less then 90.
 
I forgot question 2: If not now, was it ever against code?

When I replied to the guy asking, that if it wasn't around 358.26 then I didn't think such a rule existed, he said he believed it was against code at some point in time.
 
Often you find yourself needing something a bit over 90.Other than your the guy pulling the wire there is no problem.360 is the rule and some inspectors even allow a few kicks over that.
 
I myself have seen "shepards hooks" in a few installations.
I do not think this would be/is a violation, as long as the single run is not more than 360 degrees in bends.

If an inspector may think he has a link to a code citation, it could possibly be 110.7 Insulation integrity, or 110.12 of which all on this forum know is not really enforceable.
 
Another common place where the '90' needs to be more than 90 is when you come up a vertical column or wall onto a ceiling / roof that is pitched.

The roof of a building constructed like any HD / Lowe's is actually pitched so coming up a column with conduit results in less or more than a 90 depending on which way your heading.
 
iwire said:
Another common place where the '90' needs to be more than 90 is when you come up a vertical column or wall onto a ceiling / roof that is pitched.

The roof of a building constructed like any HD / Lowe's is actually pitched so coming up a column with conduit results in less or more than a 90 depending on which way your heading.
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How about a box at those locations :smile:
 
Pierre C Belarge said:
How about a box at those locations :smile:
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Why?

The box will be 20' off the floor, comes time to pull I need to have some one go to that box.

Sure if a box is required I will put it there but I do not see a NEC violation with a 100 degree bend.
 
I think the old book Practical Electrical Wiring might be what proliferated the myth that you shouldn't bend past 90?. That book's been in print longer than most of us have been alive, and it shows a picture of what the author calls a "gooseneck bend" and shows it as being highly discouraged and poor practice. Myself, I sometimes use a gooseneck bend going into our our of a wall or top plate if I don't happen to have an LB handy. It's formed by making a 120? bend in two shots on the bender, followed by a 30? bend back the other way to make a total 90? transition.
 
How would this be any different than back to back 90's.
We call it a goose neck bend also how often have we installed fixtures to shine on a wall that are manufactured with that type of bend?

If you don,t exceed 360 degrees your good!!
 
iwire said:
Why?

The box will be 20' off the floor, comes time to pull I need to have some one go to that box.

Sure if a box is required I will put it there but I do not see a NEC violation with a 100 degree bend.
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I like installing boxes at these locations when a spec tells us to follow BISCI recommendations, (no more than two 90's between pull points) then when the telecommunications people get there they have the nerve to complain about us following their specs. :D :D :D

Roger
 
The way this code is written one could assume intent (And many do) that a 1/4 bend is a 90 and that there be no more than 4 of them, and that 90 were the max for each depending on how you feel about the wording.... But the use of the word 'equivalent' kills that.... But it doesn't say two 180's or one 90 and a 270, nor does it mention any number of 20's, 30's etc. either... It says equivalent of 4 90 bends.... 3 - 30's make a 90... but how many 90's does a 91 and an 89 make???? NONE IMO. But doesn't prevent you from having two 90's back to back, or an off-set right next to a 90. Or a 1 degree bend right next the maximum that your bender is designed to make at 90... ;)

344.26 Bends — Number in One Run.
There shall not be more than the equivalent of four quarter bends (360 degrees total) between pull points, for example, conduit bodies and boxes.
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FYI the wording is the same ~'99 NEC.
 
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I remember when I was roughing in slabs for residential high rise buildings, any conduits going down through the slab would be where we would use this bend. Over bend the 90, then reverse the bender and pull the 90 up straight. This way it entered the ceiling below nice and straight.
I don't remember what we called this bend, but it was used frequently.
 
georgestolz said:
I forgot question 2: If not now, was it ever against code?

When I replied to the guy asking, that if it wasn't around 358.26 then I didn't think such a rule existed, he said he believed it was against code at some point in time.
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George - 1962 NEC - 348-10 - has the same language - 'equivalent' of (4) 90's.
1951 NEC - Section 3490 - Bends - same language about 'equivalent number of bends.
1930 NEC - Article 5 - Wiring Methods - 503 - Conduit Work -
503(i) - " A run of conduit, between outlet and outlet or between fitting and fitting, shall include not more than the equivalent of 4 quarter bends, the bends at the outlets or junction boxes not being counted."

NEC 1925 - Article 5 - Wiring Methods, Section 503 - Conduit Work
Section 503(f) - " A run of conduit, between outlet and outlet or between fitting and fitting, shall include not more than the equivalent of 4 quarter bends, the bends at the outlets or junction boxes not being counted."

That's as far back as my library goes - "he said he believed it was against code at some point in time." Either he has a very good memory and has been in the trade a VERY long time, or he has a bad memory.
 
dana1028 said:
That's as far back as my library goes - "he said he believed it was against code at some point in time." Either he has a very good memory and has been in the trade a VERY long time, or he has a bad memory.
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LOL - I imagine he was simply misinformed. There are many longstanding myths out there, it's easy to pick one up.

All right guys, thanks for the replies. :cool:
 
Dana,
Note the wording starting in the 1925 section that you quoted. You could have 360? of bends between each coupling as a coupling is a fitting. This was not corrected until the 1990 or 93 code where "fitting" was replaced with "pull point".
Don
 
Iwire,
You wrote: "we occasionally use it when we have stubs sticking out of walls." I assume you meant stubs sticking out of the top of a [steel stud] wall.
Looking at my little sketch, [top right] you can see that it is possible to avoid this problem if the initial work is properly planned. Often the foreman is in a hurry and justs tells his people to "get the conduits stubbed out of the walls". But this ends with the conduits pointing straight up whereas they really should be going horizontally along the top plate.
This method leaves the bulk of the bend in the wall and a shepard's crock is not necessary and it looks better. A couple of more punches in the top plate are necessary but you do have a stud punch, don't you?
~Peter
 
dana1028 said:
~~~~
NEC 1925 - Article 5 - Wiring Methods, Section 503 - Conduit Work
Section 503(f) - " A run of conduit, between outlet and outlet or between fitting and fitting, shall include not more than the equivalent of 4 quarter bends, the bends at the outlets or junction boxes not being counted."

That's as far back as my library goes - "he said he believed it was against code at some point in time." Either he has a very good memory and has been in the trade a VERY long time, or he has a bad memory.
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I've only been at this 16 years or so, but have heard the language in bold via word of mouth from all kinds of people, although it appears to not have been in the code in even my parents life times. Apparently the antiquated language has not changed much~but I have always thought I knew what it meant. Still says "equivalent of four quarter bends" though... Not 3-1/3's, 2-1/2's or any number of 1/4.01ths...

Example:
2-45?=90?
3-30?=90?
4-22.5?=90?
9-10?=90?
Total 360?


1-91?≠90?
1-92?≠90?
1-93?≠90?
1-94?≠90?
Total 370?

Why write it as (Quantity) 4 (Amount of bend) quarter bends (1/4 of 360 being 90)??? Why not leave this reference out and take the "360 degrees total" out of parenthesis in the code if more than a 90 is allowed? Anyone have a bender with >90 on it?
 
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e57 said:
Why write it as (Quantity) 4 (Amount of bend) quarter bends (1/4 of 360 being 90)???
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Don't know.


Why not leave this reference out and take the "360 degrees total" out of parenthesis in the code if more than a 90 is allowed?
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IMO if I accept your argument I can not make less then 90 degree bends either.

Anyone have a bender with >90 on it?
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Yes, I know for fact that the Greenlee smart bender goes up to at least 95 degrees.

And what about hickeys?

It is perfectly acceptable to use a Hickey to segment bend conduit, a hickey is able to make a conduit in to a coil.
 
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