# Conduit Installing in mill



## backstay (Feb 3, 2011)

We never ran EMT in a mill(industrial setting). That being said, is water or some other liquid in danger of getting into the EMT? If so, I’d use rain tight fittings.


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## SWDweller (Dec 9, 2020)

Do you have specs for the job?
I would use set screw steel fittings. No water to worry about and using steel keeps the strength up at the connections.
Mounting boxes can be handled by using beam clamps. 
There are several types, so choose wisely. Again go with something that is strong.


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## LGLS (Nov 10, 2007)

mattjmurph said:


> Two (2) part question here;
> 
> 1. Have a question about using either, set screw type emt conduit couplers, and box connectors, or compression couplers, and box connectors?
> 
> ...


Put boxes at eye level on columns, or suspend SO cables with cord caps from the ceiling in convenient but “out of the line of fire” locations.

NYC ELECTRICAL CODE required commercial garage receptacles and commercial/ industrial areas where there is any vehicular traffic like forklifts to utilize flexible cords and caps, so any snagged device cord pulled or yanked by snagging on a moving vehicle would flex in the direction of travel and simply let go.


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## Almost Retired (Sep 14, 2021)

BEAM CLAMPS
ask your SH to show you all the options
use it for the pipe also

again ... is there no spec calling for rigid?
if not, and no water problem, Steel set screw type
i just gave up on zinc anything years ago

personally i prefer minimum 3/4 EMT in a mill, just so much stronger


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## mattjmurph (Oct 13, 2021)

I do not want to use EMT at all either, I personally would use rigid aluminum. However, the plant engineer makes those decisions, just have to go with it.

As for water issues, no water leaks from the ceiling that I am aware of, though this area is exposed to changing temperatures, as it is used to get to there loading area.


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## Almost Retired (Sep 14, 2021)

mattjmurph said:


> I do not want to use EMT at all either, I personally would use rigid aluminum. However, the plant engineer makes those decisions, just have to go with it.
> 
> 
> Sent from my iPhone using Tapatalk


we just had a big long discussion on how difficult alu rigid is to pull
i have never used it, but after that discussion, i dont think i ever will


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## Slay301 (Apr 23, 2018)

Manufactured by - ERICO CADDY


BC23A000EG Machine Parts from ERICO In Stock, Order Now! Same Day Shipping, 2-Year Warranty - ERICO, CADDY, BC23A000EG ,CLAMP, STRUT, COLUMN, 1 5/8" DEEP CHANNEL, ELECTRO-GALV, SET OF TWO




www.radwell.com


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## mattjmurph (Oct 13, 2021)

Slay301 said:


> Manufactured by - ERICO CADDY
> 
> 
> BC23A000EG Machine Parts from ERICO In Stock, Order Now! Same Day Shipping, 2-Year Warranty - ERICO, CADDY, BC23A000EG ,CLAMP, STRUT, COLUMN, 1 5/8" DEEP CHANNEL, ELECTRO-GALV, SET OF TWO
> ...


Didn’t know this existed, thank you very much. 


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## RMC4ME (Oct 25, 2017)




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## mattjmurph (Oct 13, 2021)

RMC4ME said:


> View attachment 167479


That is exactly what I have seen in the past at other places, I just didn’t remember, exactly. Thank you very much. Question would be where can I find the parts, I would assume at a SH? Is this correct?


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## LGLS (Nov 10, 2007)

Um… are you errr….

nevermind. Do you have an account at any supply houses?


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## John Valdes (May 17, 2007)

I always ran ridged inside and outside in plants. I guess I was under the impression I had to.
But after reading on here about this I guess I could have run EMT or even PVC in certain circumstances.
Would have been a lot easier for sure.


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## mattjmurph (Oct 13, 2021)

LGLS said:


> Um… are you errr….
> 
> nevermind. Do you have an account at any supply houses?


Yes have accounts at all the local SH? I will have to give them a call on Monday, thank you for the information, very grateful.


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## mattjmurph (Oct 13, 2021)

John Valdes said:


> I always ran ridged inside and outside in plants. I guess I was under the impression I had to.
> But after reading on here about this I guess I could have run EMT or even PVC in certain circumstances.
> Would have been a lot easier for sure.


Ridge is what I have always ran at every mill I have been too. However, at this place the plant engineer wants EMT. So it is out of my hands 


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## paulengr (Oct 8, 2017)

LGLS said:


> Put boxes at eye level on columns, or suspend SO cables with cord caps from the ceiling in convenient but “out of the line of fire” locations.
> 
> NYC ELECTRICAL CODE required commercial garage receptacles and commercial/ industrial areas where there is any vehicular traffic like forklifts to utilize flexible cords and caps, so any snagged device cord pulled or yanked by snagging on a moving vehicle would flex in the direction of travel and simply let go.


That’s a huge Code violation.

NEC 400.8 Uses not permitted:
(1) As a substitute for the fixed wiring of a structure.
(4) where attached to building surfaces
(7) where subject to physical damage.

No way you would EVER get away with using SO in this way in 49 other states.

If it’s NOT subject to physical damage, BX or AC is quite popular in commercial settings.

Better is either type TC-ER (no metal) or PVC coated MC. The TC-ER must meet the same crush and impact as MC. Both are permitted in exposed areas. Both are legal as long as you support it every 6 feet. This gives you ONE run, no boxes or couplings except where you want them. Just have to have a clip every 6 feet max. In practice we end up going every 4 feet to keep it straight...

Attach with beam clamps and minerallacs if you don’t want to drill or just minerallacs or one hole straps if you do. Or there are one hole beam clamps. I prefer to just put the clips on a piece of strut and mount boxes to that. It is very strong and holds as much as you want. Some guys use strut and strut straps all the way every 6 feet but that’s a ton of work.

I like the compression fittings. They look MUCH better. Cost isn’t that much more. In fact it looks very similar to rigid at first glance. You are far less likely to get an inspection issue with loose or missing set screws. And you can use rain tights. Very small EMT is fairly fragile but at 1” or bigger its just as tough as GRC.

Inside beams seems like the way to go but my experience is it always seems like it needs a lot more bends. Bends to go in. Bends around every joint or structural support. It seems like it is better but then you have more conduit bodies and couplings. Running on the edge or on the surface is a straighter run with fewer joints.


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## Slay301 (Apr 23, 2018)

Wouldn’t a mill need to be explosion proof anyway


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## mburtis (Sep 1, 2018)

Maybe I'm a heathen but I've never got the infatuation with rigid. Sure if it's coming down the column where a fork lift can get at it, but way up high on the wall, in the roof, or under the floor... why go through the extra effort and cost. While I've never seen it in person, that teck 90 stuff those Canadians are always going on about seems like it would be the cats moew.


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## Slay301 (Apr 23, 2018)

Flour makes a pretty big fireball when ignited


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## CMP (Oct 30, 2019)

It’s a steel coiling mill, they don’t use flour, they just make dough. Pictures tell the story.


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## CMP (Oct 30, 2019)

I’m an old school hack, I would just bend into the web of the column and drill and tap the web and use one hole strap’s, same for the boxes. All that hardware is too expensive for my needs.

A #21 cobalt drill bit, 1/4-20 taper tap and a small bottle of tap magic is all that is needed.

If you drop the overhead conduit down a few inches away from column, it’s not a big deal to use one offset to get inside the flanges to the web. The web is typically thinner than the flanges, and building steel is soft material anyway.

Three straps for a drop, is usually more than enough, and a couple more holes for the box. 1/4-20 x3/8” screws are pretty cheap by the box. Strut hardware can easily cost 10x more, but on the flip side you have to learn how to drill and tap without destroying your tooling.


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## wiz1997 (Mar 30, 2021)

Slay301 said:


> Wouldn’t a mill need to be explosion proof anyway


Appears to be large rolls of metal in the OP's picture.


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## Slay301 (Apr 23, 2018)

paulengr said:


> That’s a huge Code violation.
> 
> NEC 400.8 Uses not permitted:
> (1) As a substitute for the fixed wiring of a structure.
> ...


Bridgeport stab In fittings are even better. No
Torquing required


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## splatz (May 23, 2015)

There are a number of ways to get the conduit into the space between the flanges, I'd say my preference is to just turn a 90 down at the top and put the offset in the vertical part. 

I have used the between-the-flanges strut hardware now and then but I really don't like the way the finished install. They're not cheap and can be hard to find in stock locally. I used to do everything with beam clamps but I've switched to drilling and tapping for the boxes. 

I have found that the Tek #5 point screws are very handy for this kind of thing, the only problem is they leave a big spike sticking out on the other side of the metal. Up high where it's out of the way that might be OK but I wouldn't want that under 8' from the floor. But they're useful even if you're drilling and tapping, you can mount the box first with the tek5's then remove the screws and use the pilot holes for a 1/4-20 drill tap. With the pilot hole, the drill tap goes very quick and easy. You can re-use the tek5's several times before the point gets dull. 



CMP said:


> I’m an old school hack, I would just bend into the web of the column and drill and tap the web and use one hole strap’s, same for the boxes. All that hardware is too expensive for my needs.
> 
> A #21 cobalt drill bit, 1/4-20 taper tap and a small bottle of tap magic is all that is needed.
> 
> ...


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## Forge Boyz (Nov 7, 2014)

splatz said:


> There are a number of ways to get the conduit into the space between the flanges, I'd say my preference is to just turn a 90 down at the top and put the offset in the vertical part.
> 
> I have used the between-the-flanges strut hardware now and then but I really don't like the way the finished install. They're not cheap and can be hard to find in stock locally. I used to do everything with beam clamps but I've switched to drilling and tapping for the boxes.
> 
> I have found that the Tek #5 point screws are very handy for this kind of thing, the only problem is they leave a big spike sticking out on the other side of the metal. Up high where it's out of the way that might be OK but I wouldn't want that under 8' from the floor. But they're useful even if you're drilling and tapping, you can mount the box first with the tek5's then remove the screws and use the pilot holes for a 1/4-20 drill tap. With the pilot hole, the drill tap goes very quick and easy. You can re-use the tek5's several times before the point gets dull.


Tek5's are awesome. As far as the metal "spike" on the back side, just go break it off with your hammer. You generally get a nice clean break at the metal, or you can hit it with a grinder if it needs to be perfect.

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## mburtis (Sep 1, 2018)

So the same plant engineers that overspec the crap out of the conduit don't freak out about people drilling holes through the structural steel? As long as it's close to the center of the web it makes no difference. Not sure I would be to keen on drilling close to the flanges though.


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## CMP (Oct 30, 2019)

The fear of engineers, you need to realize that all they normally do is cut and paste . I dare you to ask any one of them to show you the math on any one of their cut and paste jobs or any substantiation of their specifications.

Take this guy for example, saying to ask for getting engineering approval for drilling a mounting hole in a piece of sheet metal, for a strap.









CEC - First time explosion proof and enclosed spray booth


I wish we had some type of commission run continuing education classes. We have all these online courses that are more fluff that practical. I miss the in person classes. They had good hot lunches and all day coffee. It's actually really good. There are so many courses and all of them...




www.electriciantalk.com





I have drilled hundreds of thousands of holes in metal in my days, and have yet to have a failure. A bit of common sense can go a long way, if you have any common sense. Making swiss cheese is not the objective. 

They would really have a cow, if you needed to hang a 75KVA transformer off of a column, 25’ above the floor. Done that 100’s of time as well, fabricating the stands and drilling and bolting them to the column flanges. They could turn that into a week of sizemic study and still not be able to back up their assumptions.


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## mburtis (Sep 1, 2018)

Likely you could drill a hole about anywhere in building steel and it would never cause an issue. However I came from a world of designing structural weldments for mobile equipment. In those applications a hole or a weld in the wrong spot can cause a fatigue crack which left unchecked can cause complete failure. I went to a training once, one of the case studies we went through was a set of loader lift arms that broke completely in half. The cause ? About a 1 inch long weld holding a mounting block for an add on hydraulic line. 

Different world all together, but sometimes details matter.


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## CMP (Oct 30, 2019)

I agree with you, details matter. On the other hand, no engineer predicted or caught that problem until you had a stress failure in actual use. We learn by doing and testing, not just saying it can’t be done. Im sure that afterwards a change was made to prohibit welding in the high stress area was allowed, and they formulated a different way to support the hydraulic line. Experience is usually the best teacher, you don’t often forget the hard won lessons of failure. But on the other hand, you have to break an egg to make an omelette.


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## splatz (May 23, 2015)

mburtis said:


> So the same plant engineers that overspec the crap out of the conduit don't freak out about people drilling holes through the structural steel? As long as it's close to the center of the web it makes no difference. Not sure I would be to keen on drilling close to the flanges though.


This is a valid point but for 1/4-20 holes it's never going to matter. There are rules of thumb for drilling structural steel, I don't remember them though. You're allowed to drill small holes. Especially in a column, which are in compression, with the fastener filling the hole, amounts to nothing. If I recall correctly holes in the web were seldom a problem, holes in the flanges were more tricky, but that's for holes for ducts and pipes, not hilti shots and little screws. 

From more of a common sense perspective, I am far more concerned with a beam clamp coming loose and causing trouble than 1/4-20 holes in steel making a building fall down, so I'd bet a stack of 100's against a roll of quarters that the drilled and tapped install will be safer.


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## mburtis (Sep 1, 2018)

splatz said:


> This is a valid point but for 1/4-20 holes it's never going to matter. There are rules of thumb for drilling structural steel, I don't remember them though. You're allowed to drill small holes. Especially in a column, which are in compression, with the fastener filling the hole, amounts to nothing. If I recall correctly holes in the web were seldom a problem, holes in the flanges were more tricky, but that's for holes for ducts and pipes, not hilti shots and little screws.
> 
> From more of a common sense perspective, I am far more concerned with a beam clamp coming loose and causing trouble than 1/4-20 holes in steel making a building fall down, so I'd bet a stack of 100's against a roll of quarters that the drilled and tapped install will be safer.


My original post was somewhat sarcastic. Its just funny to me that you have plant engineers that will spec 3/4 or 1 inch rigid regardless of what it is, even for a thermostat wire in the office ceiling. But then turn around and let a sparky drill holes wherever they want in the red iron.


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## just the cowboy (Sep 4, 2013)

As for drilling in a beam this is what we were taught.
You *Can* drill and tap a beam, the bolt has to be the same metal or harder. it is fully filling the hole back to original.
You *Can't* drill a beam and put a nut and bolt thru it does not fill the voids.
You *can only* drill a hole for passing thru with engineers approval.

Cowboy


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## EYEamFIN (7 mo ago)

We always just use a hilti gun for securing anything to steel structure. Some 7/16 or 3/4 threaded studs, couple pow pows and your off to the races.


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## Almost Retired (Sep 14, 2021)

EYEamFIN said:


> We always just use a hilti gun for securing anything to steel structure. Some 7/16 or 3/4 threaded studs, couple pow pows and your off to the races.


what size boxes etc. do you need a 3/4 stud for?
cause it sure aint a plug box


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## Almost Retired (Sep 14, 2021)

mburtis said:


> My original post was somewhat sarcastic. Its just funny to me that you have plant engineers that will spec 3/4 or 1 inch rigid regardless of what it is, even for a thermostat wire in the office ceiling. But then turn around and let a sparky drill holes wherever they want in the red iron.


i guess you missed the "Memo"
All sarcastic remarks must be in purple text from now on


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## LGLS (Nov 10, 2007)

EYEamFIN said:


> We always just use a hilti gun for securing anything to steel structure. Some 7/16 or 3/4 threaded studs, couple pow pows and your off to the races.


You shoot three-quarter inch studs into building steel? What size is your Hilti charge, .357?


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## EYEamFIN (7 mo ago)

Almost Retired said:


> what size boxes etc. do you need a 3/4 stud for?
> cause it sure aint a plug box


7/16 and 3/4 length, and would use the 3/4 for cast FD2 boxes.


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## mattjmurph (Oct 13, 2021)

wiz1997 said:


> Appears to be large rolls of metal in the OP's picture.


Oh, yeah those ones are the smaller coils. There a bigger ones, and the same plant engineer, wondered why an EMT conduit was crushed when one rolled into the wall. Though I doubt rigid conduit would have held up much better. 


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## mattjmurph (Oct 13, 2021)

Oh and here is another one for you all, this same plant engineer, instructed the previous, electrician to install conduit, with in inches of a burner. and never thought that a burn through could happen. Well guess what happened to the control wire, that controls the e-stop for the ovens, when this happened.








Am I the only one that sees a problem here? 


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## LGLS (Nov 10, 2007)

Why the F are the controls and valves so close to the business end?


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## Almost Retired (Sep 14, 2021)

EYEamFIN said:


> 7/16 and 3/4 length, and would use the 3/4 for cast FD2 boxes.


so in another words a 1/4-20 x by variable lengths stud ?


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## mattjmurph (Oct 13, 2021)

Yeah I wonder the same thing. Another question I asked, was how the hell to you service the system, when it takes 2 days to cool down, and there is a breakdown. And some well most JB and connections are that close or under the burner box


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## Almost Retired (Sep 14, 2021)

usually the OEM places the valves for fuel as close to the flame point as they can get them for many reasons
and they also usually take the heat into consideration and provide insulation/shielding for electrical components

either that or provide a valve built with long hi temp leads to allow normal wiring at a distance and temp to allow non-hi temp wires

i suspect that some insulation/shielding has been left off, or deteriorated away and not been replaced from previous maintenance cycles
or it was not built to design drawings and specs


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## mattjmurph (Oct 13, 2021)

Maintenance Cycles, omg what are those. That is unheard of here. Such blasphemy. Well it was that way, it is changing now. 


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## Almost Retired (Sep 14, 2021)

mattjmurph said:


> Maintenance Cycles, omg what are those. That is unheard of here. Such blasphemy. Well it was that way, it is changing now.
> 
> 
> Sent from my iPhone using Tapatalk


they started teaching and preaching about predictive maintenance (this came after planned maintenance) decades ago
this concept says that you monitor every bearing and all other wear points often enough that you can actually predict when it will fail (give or take a week or so)
then you choose a down time that will cause the least disruption and loss of profit, and catch every thing else that is very close or sort of close to failure, at the same time
eventually you can lessen the frequency of monitoring times based on past history, thus creating a savings of monitoring labor
the *goal* is _zero unscheduled down time _and for some types of mills that is achievable, many others can come close. 
and a few are very simply the most cost effective with run to failure


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## Brianrayl (Oct 4, 2013)

mattjmurph said:


> Two (2) part question here;
> 
> 1. Have a question about using either, set screw type emt conduit couplers, and box connectors, or compression couplers, and box connectors?
> 
> ...


You might check with the owner's insurance. I have done jobs that required compression because of insurance. Their explanation. What if the sprinklers go off? Dead serious. What's in there now?


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## CMP (Oct 30, 2019)

Drilling “red iron”, first we were talking about hiding some vertical conduit runs inside a column web to give them some physical protection from smashing, versus clamping them to the flanges exposed. Then it morphed onto no allowance for drilling a clearance hole in a steel beam. There is a difference between a column web and a beam. Just like there is a difference between a stud and a joist. Their made of the same material, but their functions are different. How you handle them are different as well.

There is no need to drill a beam up high to provide physical protection for a conduit run, use beam clamps to anchor it. Drilling beams is just a lack of common sense. It’s not needed or desired, and could produce a failure point. Just like drilling a hole in a joist in the wrong location or too big of a size. If you are unsure of what’s allowable in a given situation it’s time to look it up or seek out trusted information, not just wing it and hope for the best.

There are plenty of examples out there of people who pay no attention to what their doing. I have been in plenty of plants where the wide flange columns had the flanges smashed and bent on more than one side of the column or a hi-lo driver that drove right off the loading dock to the pavement below. Those are incidents that are painful to the guy doing it, but he still can’t be bothered to think about it beforehand. Use some common sense before you act, it’s not rocket science.

In regards to wiring a burner manifold or other hi temp application, common sense would tell you to locate the wiring runs away from the heat zones as much as possible. Where that is not possible, you then should resort to materials that are suited for the purpose. If it’s been confirmed that thermoplastic wire insulation melts in the application its time to change materials or relocate the runs. SRML Wire is suited for the purpose at twice the temperature rating of thermoplastic wire. From the photo, the ASCO gas valve encapsulated coil or the liquid-tite conduit feeding it is not melted. That tells me that the wire used is the weak link in the application. But these things need to be considered in advance, and the proper materials procured in advance, not after their already damaged and production is down.


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## Brianrayl (Oct 4, 2013)

paulengr said:


> That’s a huge Code violation.
> 
> NEC 400.8 Uses not permitted:
> (1) As a substitute for the fixed wiring of a structure.
> ...


Check out grocery stores. SO cord coming from boxes on beams everwhere. Department stores and Big Box stores like Lowes, Home Depot, and Costco. All have it for when they move displays. I personally wired a Harris Teeter and it was specified in the prints, handed passed inspection. You might want to read the whole section. I live in Mount Pleasant, South Carolina. I can send pics if you would like.


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## kazzak (Sep 2, 2010)

LGLS said:


> Put boxes at eye level on columns, or suspend SO cables with cord caps from the ceiling in convenient but “out of the line of fire” locations. NYC ELECTRICAL CODE required commercial garage receptacles and commercial/ industrial areas where there is any vehicular traffic like forklifts to utilize flexible cords and caps, so any snagged device cord pulled or yanked by snagging on a moving vehicle would flex in the direction of travel and simply let go.


 Hello, I was a maintenance electrician for NYC in their agencies. I did pipe work and subpanels. I have an old copy of the NYC code, and it was officially ended with the 1997 edition. From there the city went to the NEC. Just random info guys.


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## mattjmurph (Oct 13, 2021)

Brianrayl said:


> Check out grocery stores. SO cord coming from boxes on beams everwhere. Department stores and Big Box stores like Lowes, Home Depot, and Costco. All have it for when they move displays. I personally wired a Harris Teeter and it was specified in the prints, handed passed inspection. You might want to read the whole section. I live in Mount Pleasant, South Carolina. I can send pics if you would like.


I would be interested in seeing how that turned out, post some pictures. I always like to learn from others.


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