supports

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rmonroe

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Article 358.30 : Securing and Supporting of E.M.T.

When making a vertical drop from the building's periling in open air (from the ceiling to the equipment) that exceed the 10? maximum for E.M.T., Should cord or seal-tight, using the proper stain relief?s, be used in place of E.M.T.?

rmonroe
 
Re: supports

Cord is limited in use, a piece of equipment that could have been wired with EMT probably does not fit the requirements to use cord.

Seal tight would need support every 4 1/2'.

I would suggest IMC or RMC, the supports can be 20' for vertical risers.
 
Re: supports

Using cord and the proper strain relief is the most common method. On a large building, such as a 4 acre manufacturing plant I did a couple of years ago, it was 35' from purlans to floor and 35' between bays. We found out the first winter that you don't want to use pipe from purlan to fixed machine or floor. The snow load on the roof can cause 3-7" of downward movement. After an over-night snow of 5" we had 3/4" airlines bowed like longbows! If you could come down columns where there won't be much movement pipe would be okay but out in the open, use cord and Adalet Sky-Tys at the top and Kellums grips at the bottom to a hub on an approved box or twist lock cord cap.
 
Re: supports

Amptech, are you are saying the cord is hardwired at both ends?

400.7 Uses Permitted.
(A) Uses. Flexible cords and cables shall be used only for the following:
(1) Pendants
(2) Wiring of luminaires (fixtures)
(3) Connection of portable lamps, portable and mobile signs, or appliances
(4) Elevator cables
(5) Wiring of cranes and hoists
(6) Connection of utilization equipment to facilitate frequent interchange
(7) Prevention of the transmission of noise or vibration
(8) Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection
(9) Data processing cables as permitted by 645.5
(10) Connection of moving parts
(11) Temporary wiring as permitted in 527.4(B) and 527.4(C)

(B) Attachment Plugs. Where used as permitted in 400.7(A)(3), (A)(6), and (A)(8), each flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet.

Exception: As permitted in 368.8.
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400.8 Uses Not Permitted.
Unless specifically permitted in 400.7, flexible cords and cables shall not be used for the following:
(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar openings
(4) Where attached to building surfaces
Exception: Flexible cord and cable shall be permitted to be attached to building surfaces in accordance with the provisions of 368.8.
(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings
(6) Where installed in raceways, except as otherwise permitted in this Code
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Unless you are coming out of a busway switch I would say you have a violation.

Just to be fair I will let you know I hate cord. :p

For your roof problem I would suggest expansion joints on the pipe run.

Bob
 
Re: supports

No, I am not saying hardwired on both ends. I said either a twist lock cord cap or a hub on an approved box(pendant). Why do you hate cord when it is installed in a code compliant manner? In the application I referenced cord was the best solution. In the manufacturing world today most companies are following a continuous improvement system where production cells are re-arranged regularly. The place I worked was kind of like the army. We would move a whole assembly line cell 100 yards across the plant and 6 weeks later we would move it back. Cord was a safe, economical solution for supplying power to equipment. With 3-7" of travel you need to consider the conductors inside that pipe with all those expansion joints. The code articles you cited make it clear that what I suggested is completely code compliant.
 
Re: supports

Thanks Dave :D I thought I should make it clear what my perspective is, kind of a full disclosure statement. :D

Originally posted by amptech:
The code articles you cited make it clear that what I suggested is completely code compliant.
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It is my opinion it is not code compliant, I do agree it is done commonly.

For starters which one of the code articles allows you to attach the cord to the building structure?

[ April 07, 2004, 07:06 PM: Message edited by: iwire ]
 
Re: supports

Who said the cord was attached to the building structure? Attaching cord to the building structure would be a violation.Are you familiar with a saddle cord grip called a sky-tye used with a spring? This device is attached to the building structure. How about a Kellems loop grip for supporting cord in a pendant install? Do you not believe pendants are code compliant?
If it is not allowable, what is the purpose of 400.7(A)(6)? The installation I described does not employ any of the methods listed in 400.8.
 
Re: supports

OK,
Musical machine moves are nothing new, the method that would work the best would be a busway system with cord drops, however you must remember these fortune 500 companies would out source you in a minute, if you installed that type of a system, twenty or thirty years ago, it would be approved, plants were engineered back then, and they were built for the long term, today most of these plants not only move the machines often, they move the plants and people.
Bob, i feel the same way about the use of cords as you do, however,
"In the manufacturing world today most companies are following a continuous improvement system where production cells are re-arranged regularly."

And if they are using this system, they should provide busway duct, not long lengths of cord.

Bob, at the rate they are going, the plant production floor should look like a third world distribution system, good to know , we still have some craftsman like yourself out there.

[ April 07, 2004, 11:08 PM: Message edited by: satcom ]
 
Re: supports

Originally posted by satcom:
OK,
Musical machine moves are nothing new,.............
"In the manufacturing world today most companies are following a continuous improvement system where production cells are re-arranged regularly."
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Yeah I see this often too, machines being moved replaced etc, and if this is really whats going on rubber cord has a place. :)

IMO all to often cord is used to feed equipment that no one plans on relocating. :roll:

Auto lifts in garages come to mind, or a piece of factory equipment that has hard plumbing lines for air and or water, but is still fed with cord.

I do not lose any sleep over this, it is JMO that raceway systems are almost always a better wiring method than cords.
 
Re: supports

The cord is not attached to the building structure as I described it. It is attached to a saddle strain relief device which can be attached to the building structure. These devices are manufactured and UL listed for this purpose. Several pieces of equipment used at this facility were purchased new and arrived with a cord and a twist lock cap. Equipment such as 3 phase 50A heat seamers, small 3 phase punch presses and sewing machines. All of these installs were approved by the State Inspector as well as IOSHA before and after installation and deemed code compliant. I guess in your opinion I am just a 25 year master DYIer.
 
Re: supports

The cord is not attached to the building structure as I described it. It is attached to a saddle strain relief device which can be attached to the building structure.
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:confused:

Just what method of connecting the cord to the building structure would you consider attached? :confused:

I know the devices you speak of and they are UL listed for the purpose, that does not mean that every place you use one of these on a code drop, it is code compliant.

The fact that an inspector did not say anything about these cord drops does not necessarily mean it is code compliant.

We have inspectors for each town in this state, some will allow what you describe others will not allow that. :confused:

We just have a difference of opinion on this.

Bob

[ April 08, 2004, 04:20 PM: Message edited by: iwire ]
 
Re: supports

Using jiffy clips or tie wraps to attach cord to a building would be attaching cord directly to the building and would be a clear violation and the hazzards involved with that practice are obvious. I didn't say "the inspector didn't say anything about it" I said the State inspector approved it as did the IOSHA official. They were approached specifically on the matter before any cord drops were installed. The State Official cited 400.7(B)when approving the installations. The only stipulation made was that nothing less than SOOW grade cord be used.
 
Re: supports

iwire,

I bet you're a nervous wreck when your wife is running the vaccuum cleaner around the house with that nasty cord attached. :D
 
Re: supports

When our shop runs into similar situations, we will use 20 foot lenghts of back to back deep "strut" ,anchor a "strut" foot to the floor, anchor to roof members and support raceway by approved means on the strut.
 
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