Flimsy EMT drops from 20ft ceilings

[Mule]

Im making several EMT drops from 20ft ceilings. I've tried Unistrut on the bottom 10ft, Rigid, Unitstrut and Rigid, Hanging from Allthread from lower elevations. Nothing really suites me, it still seems flimsy. What's a sturdy method? These are 30amp and below in size, and both 480v or 120v.

Im also thinking about cord drops, Kellum grips, aircraft cable, and cord connectors///:smile:

 

[infinity]

We've used 3/4" and 1" RMC with a floor flange on the bottom, support at the top, and a T condulet a few feet above the floor made up wrench tight. If this still feels flimsy you can use a larger size conduit.

 

[iwire]

Get 20' lengths of 1 5/8" x 3 1/4" strut.

Or if you can weld butt weld two 10' sections together.

 

[iwire]

We've used 3/4" and 1" RMC with a floor flange on the bottom, support at the top, and a T condulet a few feet above the floor made up wrench tight. If this still feels flimsy you can use a larger size conduit.

That is a nice clean way as well. :smile:

 

[Ed Carr]

Mule,we've done the same thing at a small factory with 25' ceiling.
Yes they seem a little flimsy but there has been no problem with them. Ed

 

[Mule]

Get 20' lengths of 1 5/8" x 3 1/4" strut.

Or if you can weld butt weld two 10' sections together.

I recomended "back to back" strut to my client, but didnt realize it came in 20ft lengths...great idea.....Let's see how am I going to put that on my van? This place is out in the boonies....

 

[infinity]

That is a nice clean way as well. :smile:

Actually it is and it's pretty strong as well. Any use of EMT for this type of installation is a nightmare when you try to support it. I've seen all sorts of contraptions, double strut 10' high with cross members for pipe support and fancy 45 angle brackets on the floor. Must have cost a fortune for those installations.

 

[peter d]

Get 20' lengths of 1 5/8" x 3 1/4" strut.

Or if you can weld butt weld two 10' sections together.

There is a Staples store near me that they put in an old Pace warehouse when they went bust. So naturally it has much higher ceilings than the typical Staples. To do the drops for the store fixtures they did exactly that - used the deep unistrut. It doesn't look as nice as a power pole but it does the job for that distance quite well.

 

[Buck Parrish]

Im also thinking about cord drops, Kellum grips, aircraft cable, and cord connectors///:smile:

[/QUOTE]T




this is the way to go.

 

[Mule]

Yesterday, I came "Up" 3ft from bus duct, over 11ft, left 3ft, and down 11ft to the top of a machine. This was 1"EMT, hung from two rod clamps, and 10ft sections of all thread on 5 ft centers.....still flimsy. I know everyone does it, but I don't like running 480 like that.....seems dangerous to me.

 

[iwire]

this is the way to go.

Have to be very careful with cord drops if the plant is subject to OSHA inspections. The box at the end of the cord must be designed to be a pendent box, no 4" squares, no bell boxes etc.

 

[growler]

I recomended "back to back" strut to my client, but didnt realize it came in 20ft lengths...great idea.....Let's see how am I going to put that on my van? This place is out in the boonies....

Have the strut delivered. If you are going to drop more conduits at the same spot then you may want to look at useing channel iron and just build a rack. When it come to industrial I'm not afraid to do a little welding if it comes to it ( in residential and commercial people look at you funny).

 

[Mule]

Have to be very careful with cord drops if the plant is subject to OSHA inspections. The box at the end of the cord must be designed to be a pendent box, no 4" squares, no bell boxes etc.

How about a female cord grip on the bottom with a strain relief Kelum and aircraft cable. is that legal?

 

[Buck Parrish]

Have to be very careful with cord drops if the plant is subject to OSHA inspections. The box at the end of the cord must be designed to be a pendent box, no 4" squares, no bell boxes etc.

It's a lot easier. If it is allowed in your facility.
And will fit in the van.:smile:

 

[cadpoint]

Did you try a complete a ladder or cross structure from ceiling to floor ?

I like to use a structural members of an "L" or sideways "L" or even a corner plat, all bolted together at floor and ceiling !

To stiffen up anything, try a 1/2" dia. conduit over your threaded rod, and tighten that against the other structures.

The conduit will take the flimsy out of your structure, the braces will make it more rigid for sure.

 

[Mule]

Did you try a complete a ladder or cross structure from ceiling to floor ?

I like to use a structural members of an "L" or sideways "L" or even a corner plat, all bolted together at floor and ceiling ?

To stiffen up anything, try a 1/2" dia. conduit over your threaded rod, and tighten that against the other structures.

The conduit will take the flimsy out of your structure, the braces will make it more rigid for sure.

Sounds great and that would work, but this client makes changes equipment locations like all the time. Im afraid it would be too expensive.

 

[iwire]

Just a heads up, if it is a steel truss building that is subject to snow loads and you are not close to a building support column I urge you to make the connection at the top end in a way that can move.

The roof will move down with a snow load and bow out drops that are secured at both ends.

 

[Mule]

So, in my brain...."Extra hard usage cord", with a aircraft pendant cable, strain reliefs, and a female cord grip...is LESS likely to recieve physical damage than the other methods we are talking about.....am I wrong?

 

[Mule]

So, in my brain...."Extra hard usage cord", with a aircraft pendant cable strapped to the side, strain reliefs, and a female cord grip...is LESS likely to recieve physical damage than the other methods we are talking about.....am I wrong?

Knock Knock, Hello? anybody got a opinion about this?

 

[iwire]

Knock Knock, Hello? anybody got a opinion about this?

I hate rubber cord used for permanent wiring.