ECN Forum
Posted By: safetygal flexible cords - 08/28/12 07:16 PM
I was asked if the following use of flexible cord was OSHA and NEC compliant. I am a safety officer and electical compliance is not my strength. I would appreciate all feedback. These conditions are in an industiral site, not construction site.

1. Can flexible cord be used to hard wire a electric arc welding machine directly to a main disconnect? (No plug or outlet.) The machine is removed occassionally for maintenance, but has to be calibrated every time it is returned to service so the removal is not done frequently. Monthly may be the most frequent this is done.

2. Can a flexible cord be hard wired to a disconnect at one end, with a receptacle at the other end? (I've heard it called a pig tail.)
Posted By: gfretwell Re: flexible cords - 08/28/12 09:26 PM
The real question is if the welder is listed for cord connections at all. That could be the show stopper.

If so;
Yes and yes with the caveats that this cord can not be run through the wall, raceway or other structure, it must be free from the likelihood of physical damage and it must have the proper strain relieving grips on each end.

If it does list a cord and plug connection, a better alternative is a cord and plug on the welder going to a fixed point receptacle using regular chapter 3 wiring methods
Posted By: HotLine1 Re: flexible cords - 08/29/12 02:29 AM
I agree with Greg, but...the 'gray area' is how often is the welder moved? "frequent interchange" (400.7(6)) is open to opinions. If you are the compliance officer, that would be your call. Common trade practices on my side of the Hudson is Chapter 3 wiring to a receptacle, and a cord with cord cap on the unit.

The second part of your question (pigtail) IMHO is NO
Sounds like the cord is being used for fixed wiring. Again, the term 'pendant' is not defined within Article 100, and is also a 'gray area' and subject to opinion.

Article 400.7 & 400.8 spell out the 'can & cannots' for rubber cords.



Posted By: gfretwell Re: flexible cords - 08/29/12 04:06 AM
"Pendant" is derived from the latin word pendere, meaning to hang down. A cord pendant hangs down from a box, wireway or other raceway system. (in my patch)

There was a "wink and nod" exception for pigtails under a computer room floor but they want it in MC and it is usually limited to 6 feet.
They use the language in 645.5(E) to justify it.

Quote
Power cables ... or for, information technology equipment shall not be required to be secured in place.


After all of that it usually ended up being Greenfield
Posted By: HotLine1 Re: flexible cords - 08/29/12 04:33 AM
Yes, the wink & nod does happen.

The last 'cord' battle was for a fast food prep area with the equipment requiring cord connections for cleaning the lines. That AHJ was adamant; cord could not be hard wired from a 5x5 at the ceiling (flush), strain relief, and a cord cap all of about 4+/- feet. The AHJ wanted a TL receptacle in the 5x5 (flush at ceiling) and the cords on the equip to be long enough to reach. A few weeks of arguements, a trip to the Board of Appeals, and fast food won the appeal. BTW, cord caps were all pin/sleeve
Posted By: gfretwell Re: flexible cords - 08/29/12 05:14 AM
That is pretty standard at a couple of the burger joints.
They are legitimately a pendant so it will be a tough fight for the AHJ. The argument from the management is it prevents the employees from having to use ladders to disconnect the equipment. They fear falls (maybe into hot grease or griddles) more than electrical problems and OSHA will back them up.
I saw a kid slip and stick his hand into a fryer once, It was not pretty. We got it in ice as fast as we could but the kid's hand was never the same.
Posted By: HotLine1 Re: flexible cords - 08/29/12 01:28 PM
Greg:
I agree; safety is paramount.
Posted By: renosteinke Re: flexible cords - 08/30/12 06:08 PM
OK, time for a little venting ...

You've all seen the pictures - many posted by me- of the outrageous things folks do with cords. Let's pause a moment, and reflect:

In nearly every one of those pictures, the use of a flexible cord was the least of the issues. There are almost always other issues that, IMO, are more important. Cord too small, cords being damaged, improper connections, etc.

Code may not make any distinctions as to the 'gravity' of a violation, but only a moron would claim that all violations were equally dangerous.

Nor is the NEC the only, or even the overriding, concern. However passionate we may feel, however 'dangerous' the situation may be. The discussion (above) regarding deep-fryers is one such example.

Nor is something good, or 'safe' just because the code allows it. Examples of such 'legal' idiocy that I have seen include lights over swimming pools and electric baseboard heaters in athletic SHOWER rooms.

My biggest rant, though, is against the automatic assumtion that if a cord is used, it must be wrong. Sometimes this assumption is even 'built in' to the 'listing and labling.' Well, that sword cuts both ways.

If it's against the 'listing and labling' to wire a water heater with a cord - regardless of the cord size or strain relief provided- is it not also a violation of the 'listing and labling' to remove a cord from a welder, only to replace it with a length of flex?

So what if the cord is hard-connected to a disconnect switch or junction box. IMO, anyone who considers running a cord inside a raceway just enough to make a connection to be a violation is a fool.

"Do not use a cord in place of a permanent wiring method." Well, you're not. You ran 'permanent' wiring as far as you could. Past that point, you're altering the equipment.

Is cutting off the plug altering the equipment? I say NO. I say this in part because there is no requirement that a particular plug be used; there is the issue of maintenance and repair, and because even UL is very careful to distinguish between the cord and what it's connected to. There are many products that are not UL listed, yet have a UL lable on the cord!

We also see this assumption arise EVERY time someone makes a pendant; it seems some folks are not able to ever imagine how a cord might actually BE part of a proper permanent wiring method.

Nor should we ignore "non-NEC' reasons that someone might take into consideration. For example, the theft of equipment, the desire to reduce cord 'clutter,' or the desire to put the LOTO point in a more accessible location.

Finally, do we KNOW it's a 'flexible cord' as described in the NEC? Not everything that looks like SO really is SO. If it's the cord that came with the machine, chances are it's an "appliance cord" and not addressed by the 'flexible cords' part of the code at all.

So the OP has a welder that's tied to a disconnect. If that's the biggest problem he has, that's a darn good shop!
Posted By: HotLine1 Re: flexible cords - 09/01/12 01:31 AM
Reno:
I would say that IF someone had a welder that came from the mfg with a cord & cap, and someone removed that and connected it with NM, MC, AC, or a raceway & THHN/THWN-2 that may raise my eyebrow. Is it any 'safer'? I would say it would depend on the skill of the person that made the change, AND...is the flexibility of the original wiring method something to be considered? Is the NM, MC, AC, THHN etc stranded or SOLID?? Things to consider!

Local (NJ) trade practice is to 'hard wire' electric water heaters & furnaces. I have not seen anyone use cord, and honestly...I have no knowledge on hand IF either can be wired with cord.

Changing a cord cap (plug) from a twistlock 120v/20 amp) to a straight blade on a pool pump will be an issue. Replacment of a cord cap on a cooking appliance with a 'like' is no issue.

Putting a 20 amp male & female, 120 volt cap on a 100' length of 12/2 MN is that an issue. Is that done? Yes! Do I like it? NO! Do I 'tag it'? Depends! Why? Basically, is it SAFE?, is it wired correctly? How long will a solid conductor survive? That is a place for cord; would I tag a 'homemade' extension cord of SO/SJ, etc.; if it was safe & wired right, NO.

Posted By: gfretwell Re: flexible cords - 09/01/12 04:24 AM
I think this cord cap thing is more U/L lawyer than safety but it is true.
I was the authorized manufacturer rep and I could do any thing I wanted on the load side of the line cord but the machine was listed with a U/L cord and if I altered the cord I wasn't listed anymore. Rulz is rulz.
Posted By: sparkyinak Re: flexible cords - 09/01/12 07:06 AM
Yeah, what greg said...
?=^)

Welcome to the board where we just say it like it is
Posted By: JBD Re: flexible cords - 09/09/12 11:17 PM
UL says they are unable to state that a field modification to a listed item automatically 'voids its UL Mark'. UL says approval is up to the AHJ, and that they are to ask for assistance in evaluating field modifications, if necessary.

The primary issue with UL and cords, has more to do with changing from cord to other wiring, or more typically from other wiring to cord.
Posted By: harold endean Re: flexible cords - 09/10/12 01:44 PM
I get that argument all the time when it comes to above ground pool motor wiring. Usually the motor comes with a cord that is 16 ga wire. When I state that the NEC says 12 ga min. the EC usually says that if he changes the cord, he will void the UL listing.
Posted By: gfretwell Re: flexible cords - 09/10/12 04:14 PM
The way we understood it, if you replaced the cord as an assembly with a cord that was another option on that piece of equipment, it was still listed. The problem was when you altered a listed cord (which usually has a separate listing from the equipment)
Posted By: HotLine1 Re: flexible cords - 09/11/12 01:32 PM
Pool filter pump motors for above ground pools are PITAs. Hard to believe there are still 16/3 & 14/3 cords with straight blade plugs being a 'part' of the pool package.

Debates on 'who' is responsible for the cord that is on the motor. There are listed NEC compliant replacement cords with the TL plug on the shelf at a local pool/spa dealer.

Posted By: gfretwell Re: flexible cords - 09/11/12 06:28 PM
This cord thing lands squarely on U/Ls back. The listing standard for pool pumps should include the 12 gauge wire and twist lock plug.

I suppose they might try to use the "storable pool pump" loophole but storable pool pumps are listed under a different standard and they are labeled differently so that is not really an excuse.
Posted By: gfretwell Re: flexible cords - 09/11/12 10:10 PM
This pool pump thing is interesting. I did some research and I suppose it really depends om the brand.
Pentair/Sta-Rite shows the same pumps with a 3 foot and 25 foot cord option. That begs the question, how are these labeled?( "permanent" or "storable" pool pump)
I know mine is labeled "permanent pool only" (or words to that effect).

Hayward Power Flo, the ones they say you use with an above ground pool, say this in the installation manual.

Quote
Wiring
Pump MUST be permanently connected to circuit. If other lights or appliances are also on the same circuit,
be sure to add their amp loads before figuring wire and circuit breaker sizes. (NOTE: If unsure how to do
this or if this is confusing, consult a licensed electrician). Use the load circuit breaker as the Master On-Off
switch.
Posted By: HotLine1 Re: flexible cords - 09/12/12 01:51 AM
That's interesting from Hayward. I guess that ALL the above ground pools are in violation of 110.3 (b)!!

I can't recall an AG pool that was hard wired.
Posted By: gfretwell Re: flexible cords - 09/12/12 02:37 AM
It does make you go humm if you are strictly a by the book 110.3 guy. I suspect the lawyer got to the author after the electrical engineer finished.

More interesting to me was the same pump model being offered with 3'& 25' cords from Pentair. I have never seen a pump labeled storable or permanent. They are usually a different model number ... at least.
All of the storable pumps I have seen were actually a little shaded pole thing that hangs over the edge of the pool but I really have not seen that many.
Posted By: HotLine1 Re: flexible cords - 09/12/12 02:45 AM
The few 'storable' I came upon were double insulated motors, with 25' cords & a tag to 'use only in a GFI protected outlet'

I noticed quite a few along the lagoons this summer, but did not notice the pumps.

Posted By: harold endean Re: flexible cords - 09/14/12 02:51 PM
Greg, John,

How about with this new code stating that you can have a regular GFI outlet within 6 foot of the pool. What is to stop people from using a regular plug in a normal outside (GFI) protected recptacle?
Posted By: HotLine1 Re: flexible cords - 09/14/12 07:32 PM
In a short answer...nothing, nada, zilch.
Posted By: gfretwell Re: flexible cords - 09/15/12 12:34 AM
... as long as the plumbing is set up so the 3' cord will reach
Posted By: harold endean Re: flexible cords - 09/17/12 01:20 PM
So in other words, you will not need the twist lock and you can use the regular outlet 6 feet away? Right? smile
Posted By: HotLine1 Re: flexible cords - 09/17/12 01:27 PM
Or, the orange extension cord, to a power strip, to a GP outlet (no GFI) in the garage.

It's been an interesting pool season so far.
Posted By: harold endean Re: flexible cords - 09/17/12 01:35 PM
John,

The best (worst) pool wiring job I seen was a motor (on an extension cord) plugged into a surge suppressor strip right next to the pool, where the pool crawler vacuum was also plugged in. Then it went to a 100 foot blue extension cord, that was plugged into a 100 foot orange cord, that ran down to the house, up over the roof of the house, which also plugged into a yellow cord that plugged into a receptacle in the back of the house. ( I don't even know if the receptacle was GFI. I told the lady whose kids were swimming in the pool that I though the install might have been a little dangerous. (to say the least) They got out of the pool right then.
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