1-1/4 Inch Conduit

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charlie b

charlie b

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Semi-Retired Electrical Engineer
I had a former supervisor (engineering design) who flatly refused to approve any design that used a 1-1/4 inch conduit. He required us to change it to 1-1/2, even if we could show that the smaller conduit met code requirements. We could never get him to tell us the basis for his policy. We only knew that his basis did not come from the NEC.

Can anyone give me any ideas as to what might have been the reason? Has anyone encountered this before? Could it be something about the standard sizes that are typically carried by the supply houses or that are typically brought to a job site? Could it have something to do with the ease of pulling cables through the conduit? Is the cost difference so small that you might as well get the bigger size, if only to allow for future expansion?
 
Re: 1-1/4 Inch Conduit

Charlie b, I've had a few jobs where the design required 1.5" over 1.25" where 1.25" would suffice, and the only thing it did was increase the estimate in that it eliminated the use of common hand benders and would mean Chicago, Sidewinders, or Hydraulic type benders.

My company charges (per job) rental for the use of these type tools and the customer ends up with the bill.

Roger
 
Re: 1-1/4 Inch Conduit

1 1/4" conduit is too hard to conveniently bend by hand and what may be saved in material costs is more than made up for by the extra labor costs involved. Too many electricians weigh less than the 300lb. required to sucessfully bend the stuff.

Each size of conduit requires a matching stockpile of connectors, couplings and supports [UniStrut clamps, Minnies (Conduit hangers), one and two hole straps, Caddy clamps, etc.]. If just one of these parts runs out of stock, production comes to a grinding and expensive halt.

Too often the designers, architects and engineers in their air conditioned offices and moccasins limit their reality to theiir charts and tables. For instance, we have to follow a complex set of rules for a load calculation for a house [Article 220] but when we go down to Home Depot, it all comes down to either a 100 amp panel or a 200 amp panel. You can order a 125 amp panel but will have to wait 2 weeks, pay more and maybe get the wrong one.

We have sucessfully eliminated 3/8" conduit and 1 3/4" conduit. The days of 2 1/2" and 3 1/2" are numbered. Why bother with IRC? If you really need protection, go whole hog. Actually, if you need more capacity than 1", go to 2" or use two 1" runs.

~Peter
President and Corresponding Secretery of the International Institute for the Abolishment and Elimination of 1 1/4" EMT. :D
 
Re: 1-1/4 Inch Conduit

Peter, are you kidding, I have a 175-185 lb third year apprentice that can do excellent bends in 1 1/4 " emt all day long with a standard hand bender.

It is simply in the technique.

If you had a job with say 5000' of 1 1/4" verses bidding 1 1/2" emt today, I would give good odds that the labor in hand tool use could overcome the difference in price.

Roger
 
Re: 1-1/4 Inch Conduit

Too often the designers, architects and engineers in their air conditioned offices and moccasins limit their reality to theiir charts and tables.
Click to expand...
As an Eee-lektrikul Injun-ear myself, I feel kind of insulted by this statement
:) ...)

Just my 2?

Scott
 
Re: 1-1/4 Inch Conduit

Roger, I am replying to your post #2: the only thing it did was increase the estimate in that it eliminated the use of common hand benders and would mean Chicago, Sidewinders, or Hydraulic type benders.
Any contractor doing commercial work should be equiped with common tools such as a mechanical bender, a tugger, a large punch set, and ladders. The cost of these should be included in the overhead. Peculiar items such as scissor lifts, cranes and coring services should be added costs to the job.
You expect your employee to pay for the purchase of a 1 1/4" bender so that you can avoid the cost a machine that you should have anyway if you are in the contracting business.
~Peter
 
Re: 1-1/4 Inch Conduit

Charlei I don't see a lot of 1 1/4" installed. I don't like it as its really easy to get it confused with 1 1/2" the fittings are so close in size. The wholesale houses don't stock much 1 1/4". The bender issue may be part of the answer.
 
Re: 1-1/4 Inch Conduit

Just finished a large commercial remodel. Turned an old building into apartments (42 of them). The plans spec'd 1 1/2, but we used all 1 1/4 inch for the panel feeds. Plans showed all panels as 100 amp 3 phase, number 3 wires. After we had the service inspection, POCO refused to connect power saying they would not allow 3 phase in a residence. Had to go back and convert everything to single phase. Ended up that 1 1/4 was large enough for what we needed, but some of the wire pulls were tough to say the least. Wish I would have went with 1 1/2"
 
Re: 1-1/4 Inch Conduit

Peter, we furnish all the benders from 1/2" up.

As far as
Any contractor doing commercial work should be equiped with common tools such as a mechanical bender, a tugger, a large punch set, and ladders. The cost of these should be included in the overhead.
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we have numerous mechanical benders and tuggers but these are charged to the job and is in the job cost but who do you think ends up absorbing this cost, yes it is the customer.

If the cost can be reduced why not?

It may be a local issue, but I have no problem with availability of 1 1/4.

Roger
 
Re: 1-1/4 Inch Conduit

Roger,

Is these use of a hand bender or a mechanical bender a line item in your bid? I.e.
Charge for use of mechanical bender for 1 1/4" EMT => $14/day
Charge for use of hand bender for 1 1/4" EMT => $2/day

Do electricians have to be fat?
Unless you are fat, you can't bend 1 1/4" EMT with a hand bender.

In your air-conditioned office it may look like you are saving 50?/ft [or whatever] by using 1 1/4" but in the field, this is costing you money because of the extra time and effort involved. Everyone has their physical limits and 1 1/4" is a grey area.

But my general argument is that 1 1/4" is outdated much like the carpenter's use of the penny system for designating nails.

Once I had to replace a feed tube for a drinking fountain. I glanced at it and went to the hardware store. It looked about 1/2". The clerk asked if it was 7/16", 1/2" or 9/16"? Why have all these different sizes?

~Peter
 
Re: 1-1/4 Inch Conduit

I weigh 160 pounds and I run 1 1/4 EMT quite well.24 years this August,I've never bought a bender for work in my life.I don't like 1 1/4,but when the specs call for it and the Contractor buys it I run it and don't complain about it.I'm with the crowd that doesn't like to stock the extra fittings.It does come in handy to be able to run a large conduit without a power bender.I prefer to use a Chicago-style bender for small EMT jobs requiring several different sizes of EMT.
 
Re: 1-1/4 Inch Conduit

Peter, we figure in a large tool adder when large company owned tools are involved in the project, and someone has to cover the cost wouldn't you think?


Unless you are fat, you can't bend 1 1/4" EMT with a hand bender.
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Huh!!! :roll:

Roger
 
Re: 1-1/4 Inch Conduit

When I was a pre-apprentice for the electrical union (I was about 20 and weighted about 130 lbs.), my journeyman and I had to field bend some large EMT (I think it might have been 2"). He had me stand on the shoe while he pulled on the handle. The conduit kept flattening out at the bend. He kept blaming me for not putting enough weight on the bender!!!

Wait a minute, I'll be back after lunch :D
 
Re: 1-1/4 Inch Conduit

In the good old days :D , before we got a hydraulic bender, I have bent 1-1/4" rigid steel conduit in the crotch of a large tree, and over the wheel of a railroad car, to name a few examples.

On one job where we needed many offsets in 1-1/4" EMT, we used a sleeve hole in a 6" concrete floor slab, chipped out to the proper radius.

Ed
 
Re: 1-1/4 Inch Conduit

Thanks for the insights. To the extent that I might have an influence in the company that I just joined, I will discourage the use of the 1-1/4 inch conduit.
 
Re: 1-1/4 Inch Conduit

This is baffling to me. :)

One thing that IMO helps with hand bending 90 sweeps in 1 1/4" is to put the welded seem on the inside radius if possible.

~Bob
 
Re: 1-1/4 Inch Conduit

From some of the posts I have been reading it sounds like some of you have or have seen hand benders for larger than 1 1/4....cant be?
 
Re: 1-1/4 Inch Conduit

Anyone else ever used sand to bend conduit?
fill it Cap it and bend away.
A very old trick

Once I made a bender out of and old tire rim on a spindle, welded side plats for differant sizes to keep the wall of the pipe from colapsing with a shoe accross the plates to retain the pipe and welded a long handle on it to use to turn the rim to bend the pipe. worked very well. Sometimes you had to do with what you had to get the job done.

[ June 30, 2004, 01:25 AM: Message edited by: hurk27 ]
 
Re: 1-1/4 Inch Conduit

I will use 1 1/4" conduit where appropriate. But one problem is, as stated earlier, is that those who do not use it regularly tend to confuse part sizes and you end up with a hodgepodge of material.

I am 6'0" and weigh 282#, so I have no problem bending 1 1/4" with a hand bender. I could do it when I was only 200# (My anorexic days!)Einstein had another theory of relativity that applies to conduit bending. E(bend)=M(squared)A.
E(B)= Mass of the A**.
 
Re: 1-1/4 Inch Conduit

its really easy to get it confused with 1 1/2" the fittings are so close in size.
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Are you guys seriously saying that a (real) electrician can't tell the difference between 1-1/4" and 1-1/2" conduit fittings? :roll:

Ed
 
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