240 and 480 volt flexible cords.

[ruznic]

I am not an electrician, and don't know the code, but I have some questions about code compliance and safety. I can't find anything on OSHA about this, but I think the NEC is the final authority on electrical safety, so I'm asking here.

There are 240v, 480v, and 208v three phase, and 240v and 120v single phase circuits, on flexible cord, Terminated with receptacles, suspended from a 24
foot ceiling, to a height of about 7 feet, in an industrial assembly area, for the purpose of testing and development of machinery. What rules, if any, apply to these flexible cables being run through bar joists to get the power to a
different place?

Are there any rules about the power cords from the machinery, or extension cords laying on the floor?

Are there any rules on the length of power cords on such machinery?

Thanks,
ruznic

 

[iwire]

Read NEC Article 400, it has all the rules for the use of cords.

 

[mcclary's electrical]

I am not an electrician, and don't know the code, but I have some questions about code compliance and safety. I can't find anything on OSHA about this, but I think the NEC is the final authority on electrical safety, so I'm asking here.

There are 240v, 480v, and 208v three phase, and 240v and 120v single phase circuits, on flexible cord, Terminated with receptacles, suspended from a 24
foot ceiling, to a height of about 7 feet, in an industrial assembly area, for the purpose of testing and development of machinery. What rules, if any, apply to these flexible cables being run through bar joists to get the power to a
different place?

Are there any rules about the power cords from the machinery, or extension cords laying on the floor?

Are there any rules on the length of power cords on such machinery?

Thanks,
ruznic

WElcome to the forum. It sounds like this place is used for production? If so,,,don't they plan on working next week? next month? next year? ,, then400.8(1) pretty much puts the ka-bosh on your cords on the floor.

Secondly 400.8 (2) pretty much puts the ka-bosh on the cords in the ceiling.

Do yourself, and your company a favor, have them quit stringing cords everywhere and hire a professional.

 

[iwire]

then400.8(1) pretty much puts the ka-bosh on your cords on the floor.

Really?

Extension cords are not allowed to lay on floors?

Secondly 400.8 (2) pretty much puts the ka-bosh on the cords in the ceiling.

Not so sure I see that either.

 

[mcclary's electrical]

Really?

Extension cords are not allowed to lay on floors?




Not so sure I see that either.

They most certainly can be laid on floor, that's why I referenced that they plan on continuing to use these constantly for production. Lay a cord on the floor for a week maybe, but if the machine is gonna stay in production, it needs permanent wiring.



Second, 400.8 (2)

plainly says cannot be run through hole in STRUCTURAL ceiling, which is exactly where the op is running them. I think you're disagreeing just to disagree, as this article seems pretty clear cut to not allow what's he's doing with the cords. How can you support a rubber cord in a ceiling and still comply with 400.8 (4)? If they had an over head busway to drop from it would be different

 

[wireguru]

OSHA also has quite a few regulations pertaining to cords. I also recall seeing something about 480v connections requiring a shroud on the male (hubbell safety shroud twistlock, or pin and sleeve)

 

[iwire]

They most certainly can be laid on floor, that's why I referenced that they plan on continuing to use these constantly for production. Lay a cord on the floor for a week maybe, but if the machine is gonna stay in production, it needs permanent wiring.

From the OP

for the purpose of testing and development of machinery

Second, 400.8 (2)

plainly says cannot be run through hole in STRUCTURAL ceiling, which is exactly where the op is running them.

I do not see that.

Terminated with receptacles, suspended from a 24 foot ceiling, to a height of about 7 feet, in an industrial assembly area, for the purpose of testing and development of machinery. What rules, if any, apply to these flexible cables being run through bar joists to get the power to a different place?

It does not appear the cords pass through or are hidden by any ceiling to me, but I could be wrong.

I think you're disagreeing just to disagree,

Well I will not say that never happens here I am disagreeing because I disagree and I dislike rubber cord.

 

[mcclary's electrical]

From the OP







I do not see that.



It does not appear the cords pass through or are hidden by any ceiling to me, but I could be wrong.



Well I will not say that never happens here I am disagreeing because I disagree and I dislike rubber cord.

I dislike rubber cords too,,,,but by your theory of the macinery is not permanent because they are "testing and producing" it,,,,heck by that theory no production plant in the entire united states would ever need permanent wiring, since parts of the process are constanly being put in trucks and shipped? now nothings permanent?? You know as well as I do that,,,,if his macine is moving in and out being tested, daily year after year, they still have a "permanent wiring need" with flexible whips where the "machines" are moved in and out and tested.

 

[G0049]

I can't find anything on OSHA about this,

Go to http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9882 and scroll down to 1910.305 (g) to find the OSHA requirements for flexible cords that are part of the structure. Then go to http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9911 to find the requirements for portable cord sets. Also, go to http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9910 and read up on safe work practices, as the troubleshooting and adjusting of these machines are typically done with power on and enclosures open.

What you've described sounds fairly typical for places that build machinery. Each machine will have different electrical needs, located in a different spot, than the machine before. Some machines will go out with a complete control package, others with none. Hence the myriad of cables supplying different voltages, phases and amperages.

Some places do a good job of managing this system. Unused cords are coiled up out of reach, locked out at the supply. The cords in use are supplied by proper OCP devices, provided with strain relief, don't lay/rub on the truss chords, are labeled, no longer than they need to be, protected where they lay on the floor, carefully inspected before and after they are used, selected, connected and disconnected by trained, competent persons, etc.. These places don't do too badly on an OSHA inspection. The other places, well lets just say it can get ugly.

The accidents/fatalities I am familiar with are not usually a fault of the cords themselves, but related to poor practices at the machine. "Someone" hooks up a cord for just a minute to check something, and leaves it powered up and unattended with no warnings. I know of at least two where a 120 volt line was connected to the control cabinet lighting to brighten up the interior. Unfortunately, it back fed through control transformers, putting 480 volts various places on the machines. You could connect these machines with the best wiring method available, and still kill your co-workers this way.