# Plug in 3 phase



## Morg12345 (Jan 22, 2016)

Hello ,this is morg again
I have an opertunity to wire a small poly manufacturing facility.. This shop has machinery scattered all over the building I would like to do an overhead Trunk line that runs down the center and branching off to have cable with strain relief going down to each machine..208 3 phase service.
I have just tried to come up with ideas on how to attack this .to have stuff plugged in up above...


----------



## Ostrich Society (Dec 14, 2021)

Hey Morg, I am unclear on what you are asking. Could you provide us with some more information?

What type of equipment? Is it all cord and plug? Amperage? Ground up new construction or adding a few circuits? How far is each run? EMT, rigid, cable tray? Disconnect locations?

Those were just prompts, I was hoping to get a better idea of what you’re trying to do so we can give our 2 ¢


----------



## paulengr (Oct 8, 2017)

I hope you don’t mean busway? That stuff is so notoriously unreliable.

NEC snd OSHA are very clear. You cannot substitute portable cords for fixed wiring. It is that clear. Now if you run cable tray drops and tray cable it might look the same but it’s Code.

If it’s all truly temporary wiring then portable cords are appropriate but make sure you can defend this claim if OSHA or anyone else ever inspects.


----------



## macmikeman (Jan 23, 2007)

paulengr said:


> I hope you don’t mean busway? That stuff is so notoriously unreliable.
> 
> NEC snd OSHA are very clear. *You cannot substitute portable cords for fixed wiring.* It is that clear. Now if you run cable tray drops and tray cable it might look the same but it’s Code.
> 
> If it’s all truly temporary wiring then portable cords are appropriate but make sure you can defend this claim if OSHA or anyone else ever inspects.


Tell that to Costco and Sam's..........


----------



## splatz (May 23, 2015)

paulengr said:


> NEC snd OSHA are very clear. You cannot substitute portable cords for fixed wiring. It is that clear. Now if you run cable tray drops and tray cable it might look the same but it’s Code.


I don't think it's that clear, personally. Yes, in uses not permitted, you have 




> 400.12 Uses Not Permitted. Unless specifically permitted in 400.10, flexible cables, flexible cord sets, and power supply cords 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 open‐ ings ​(4) Where attached to building surfaces ​_Exception to (4): Flexible cord and flexible cable shall be permitted to be attached to building surfaces in accordance with 368.56(B) . _​(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings​


​
400.12(1) above is the one that a lot of people hang their hat on. It's actually not real clear to me what the heck "as a substitute" means. Keeping in mind that extension cords are portable cords and not the same as flexible cords as part of an electrical installation. Does it mean "everywhere you could use any other wiring method?" Does "as a substitute" mean EVERYWHERE not covered in the uses permitted? I'd have to say that's the broadest possible interpretation. Short of making this a very short chapter and saying flexible cords can't be hardwired into electrical systems. 

So you have the uses permitted 




> 400.10 Uses Permitted. (A) Uses. Flexible cords and flexible cables shall be used only for the following:
> *(1) Pendants. *
> (2) Wiring of luminaires.
> (3) Connection of portable luminaires, portable and mobile signs, or appliances.
> ...


The very first use permitted, 400.10(1) , will cover an awful lot. A cord connector (female / receptacle) on the end of a cord is a cord pendant. So if you don't hardwire the machines, but you put say L6-30R receptacle plugs on the end of cords dropped from above (from a reasonable height with appropriate strain relief etc.) - how wouldn't that be exactly what this permits? I have a couple customers with facilities built fairly recently that used this setup, and there were no problems with the inspection. 

I don't know if 400.10(6) was a factor. Their equipment isn't portable, but they do rearrange their lines once in a while as their manufacturing processes change. They will rearrange the machines in the order of the process when that changes. What does "frequent" mean? Daily? Once a year? How do you inspect to that if the customers say they might move them weekly for a month then not at all for five years?


----------



## splatz (May 23, 2015)

paulengr said:


> I hope you don’t mean busway? That stuff is so notoriously unreliable.
> ...
> Now if you run cable tray drops and tray cable it might look the same but it’s Code.


I believe you but there's a lot of bus duct in manufacturing facilities around here - it seems like it may have been popular locally in the 1980s - 1990s. However when I think of the places that have it, it might be something maintained by in-house staff and something I don't hear about the problems. I like the idea that the bus duct drop cable is reinforced, but then again I have a lot of confidence in SOOW in a finger-trap type cord grip. 

Still cable tray might very well be a better option in every way. It's probably going to save copper and money compared to conduit since there's no derating for fill and it's going to be more flexible for future changes. Easier to maintain than bus duct. Free from the rules for flexible cord which I find unclear. Splices / taps in cable tray might be an issue though, it may not be the busway that the OP had in mind.


----------



## CMP (Oct 30, 2019)

Another one of those WAP statements, that your just supposed to swallow. World according to paul.



> I hope you don’t mean busway? That stuff is so notoriously unreliable.


----------



## Morg12345 (Jan 22, 2016)

Ostrich Society said:


> Hey Morg, I am unclear on what you are asking. Could you provide us with some more information?
> 
> What type of equipment? Is it all cord and plug? Amperage? Ground up new construction or adding a few circuits? How far is each run? EMT, rigid, cable tray? Disconnect locations?
> 
> Those were just prompts, I was hoping to get a better idea of what you’re trying to do so we can give our 2 ¢


Most of the equpment is 3 phase 208 30 amp


splatz said:


> I believe you but there's a lot of bus duct in manufacturing facilities around here - it seems like it may have been popular locally in the 1980s - 1990s. However when I think of the places that have it, it might be something maintained by in-house staff and something I don't hear about the problems. I like the idea that the bus duct drop cable is reinforced, but then again I have a lot of confidence in SOOW in a finger-trap type cord grip.
> 
> Still cable tray might very well be a better option in every way. It's probably going to save copper and money compared to conduit since there's no derating for fill and it's going to be more flexible for future changes. Easier to maintain than bus duct. Free from the rules for flexible cord which I find unclear. Splices / taps in cable tray might be an issue though, it may not be the busway that the OP had in mind.


This is the Imformation I'm looking for...most of the connections are feed 3 phase 208 with a disconnect in a control cabinet which feeds variable speed drives .....possibly stuff could be relocated...brand new place...changes likely....conduit a pain...I'd like to feed from above...cable tray..maybe....cord and plug ..if local code allows....morg


----------



## Wardenclyffe (Jan 11, 2019)

We have these plugs on movable stuff,...


----------



## paulengr (Oct 8, 2017)

Interlinking | Occupational Safety and Health Administration







www.osha.gov





NEC gets you past the local Code inspector. When is the last time anyone did a permitted job in an j dis trial plant once it’s built?

OSHA is the one to worry about.

Don’t get me wrong here. If you support it correctly MC or TC-ER drops are just fine. If it is movable!or truly temporary then flexible cords like SO are fine..


----------



## just the cowboy (Sep 4, 2013)

Went thru this many times.
If a machine is NOT bolted to the floor and sits on a Barry type mount it is portable even if they don't move it.
If it is bolted down it is NOT portable, but may be ok if cord is used for vibration.
If it is a control cabinet not on the machine or cord is mounted to the wall it is Not portable.

Cowboy


----------



## u2slow (Jan 2, 2014)

Similar to what @Wardenclyffe posted, there's cheaper plastic pin/sleeve connectors. I have encountered them on cord whip drops in fast-food restaurants for their appliances. We use similar for powering the reefer trailers we transport.






IEC 60309 Plugs Connectors Receptacles Inlets Outlets IEC60309 - International Configurations Inc.


International Configurations stocks IEC 60309 pin and sleeve devices with UL and European approvals. North America, Europe and Global applications. IEC60309 pin and sleeve devices - Re-wirable plugs, connectors, panel and surface mount outlets, receptacles, inlets. UL and European approval...



iec60309.com


----------



## BillyMac59 (Sep 12, 2019)

What you're suggesting is what my local inspector calls a pendant drop. Flex cable , when properly supported and terminated, is an acceptable wiring method. I've used Kellems grips and springs attached to ceilings and trusses and usually terminated in a female plug end. Never had this questioned.


----------



## CMP (Oct 30, 2019)

Morg12345 said:


> Hello ,this is morg again
> I have an opertunity to wire a small poly manufacturing facility.. This shop has machinery scattered all over the building I would like to do an overhead Trunk line that runs down the center and branching off to have cable with strain relief going down to each machine..208 3 phase service.
> I have just tried to come up with ideas on how to attack this .to have stuff plugged in up above...


I have put in many thousands of machine drop with flexible drops over the years, there is a right way and wrong ways.
I suggest that you forget putting a plug at the top, read the NEC busway article for the approved methods. I often pipe the circuit to near the drop location, install a splice box on the truss, and convert to bus drop cable. Use the appropriate bus drop cable, fittings and cable supports, for an installation that is durable and materials designed for the purpose. Never had an inspector or plant voice a complaint or failure. For relocations, re pipe to the new drop location, and hang your drop back up.

Sample install photos

Sample materials. Other brands are available thru your local wholesaler.

Bus Drop Cable
Sky-Tie - Bus Drop Cable Clamp
https://www.adalet.com/Content/uploads/SKY-TIE-BUS-DROP-CABLE-CLAMPS.pdf
Beam Clamp w/2 holes for tension spring
Kellems Deluxe Cord Grips


----------

