suspended outlet?

[PoorOwner]

I saw a discussion a while back but cannot find it,

what is the consensus on adding an outlet that is suspended by a cord on the ceiling so that machines in the middle of the shop floor can be plugged in?

The ceiling will be a metal box and EMT raceway, and the voltage required is 120V 20A.

Thanks

 

[xyster101]

You can do it if the cable is thick enough. They also make these "finger traps" that take the stress off where the wire enters the box. I am not sure where you would buy one though.

 

[tab2]

It is done all the time.

Strain relief is recommended/potentially required. You want SOOW or SJOOW, commmonly known as SO cord. 12/3 will be 12 gauge (required for 20A) and have 3 wires, hot, neutral and ground.

I can get close up pics tomorrow if you want. Here is are two “labs” with them.

 

[PoorOwner]

So some 12 awg SOOW cord and cut it up with a strain relief like a gray plastic or metal one is fine? But where can I get the net thing in that picture.

 

[mm08822]

So some 12 awg SOOW cord and cut it up with a strain relief like a gray plastic or metal one is fine? But where can I get the net thing in that picture.

Google kellems grip. Buy the cord first. Measure cord od and then buy grip that has that od within its grip range.

Use a loop style in the ceiling to connect to a hook in ceiling. Loop out of a ceiling box to the loop style kellems grip so there is no strain applied to box or ceiling cord connection.

 

[PoorOwner]

Thanks, is the kellems grip on the bottom box just a net without a loop? How does it grab onto the strain relief fitting?

 

[rlitman]

Thanks, is the kellems grip on the bottom box just a net without a loop? How does it grab onto the strain relief fitting?

The wire "basket" is crimped into that box fitting. There is another style of kellems grip that can be used for the top end of the wire, to hang it from a clamp or a hook:

 

[PoorOwner]

What does the kellems grip on the suspended end, supposed to do? it is not hooked to the ceiling in that first picture.

 

[rlitman]

It is done all the time.

Strain relief is recommended/potentially required. You want SOOW or SJOOW, commmonly known as SO cord. 12/3 will be 12 gauge (required for 20A) and have 3 wires, hot, neutral and ground.

I can get close up pics tomorrow if you want. Here is are two “labs” with them.

I recommend SOOW (or equivalent) over SJOOW. The SJ cord is 300V rated, and has a thinner insulation than the 600V rated plain SO. SJ is better when you want it to be light (like the cord attached to a hand held tool). SO is better (marginally) if you may step on the cord, or when suspending it like this.

I can't really see how those cords are attached in that lab? Also, are all of those meant to be used all the time? That insanity screams busway system to me.

What does the kellems grip on the suspended end, supposed to do? it is not hooked to the ceiling in that first picture.

Not sure what you're asking.
The kellems grip in the first picture keeps the cord from pulling out of the box at the end of the cord, due to the weight of the box.
The kellems grip I posted keeps the cord from pulling out of a box on the ceiling. You could also use the first style on the ceiling box, however, that puts the weight of the cord on the box, so you need to be sure the box is extra secure (like a ceiling fan box).

 

[PoorOwner]

I think I understand the ceiling part.

Does the bottom grip you just twist it around the circumference of the cord
And twist the other end into the strain relief fitting.

 

[mvusse]

Related question: can this be done (legally) for 220v as well? How about 3 phase 220?

I am going to be moving most of my woodworking tools into my garage, and the majority is 220v, with about half being 3 phase. "Regular" 220 plug on the single phase, twist-lock plug on the three phase stuff.

 

[PoorOwner]

So it seems I have to get the fitting like this one already have the net.

https://m.platt.com/Products.aspx?pid=289993

 

[rlitman]

Related question: can this be done (legally) for 220v as well? How about 3 phase 220?

I am going to be moving most of my woodworking tools into my garage, and the majority is 220v, with about half being 3 phase. "Regular" 220 plug on the single phase, twist-lock plug on the three phase stuff.

Sure. I use 5 conductor SO cord at work regularly. You'll just have to get it at an electrical supply house, because HD doesn't stock that sort of stuff (or kellems grips).

I think I understand the ceiling part.

Does the bottom grip you just twist it around the circumference of the cord
And twist the other end into the strain relief fitting.

Twist? The cord pushes in. It's a chinese fingercuff, so it works best if you compress the basket along its length before pushing the cord through.

So it seems I have to get the fitting like this one already have the net.

https://m.platt.com/Products.aspx?pid=289993

You could do that. Alternatively, you could bolt a ring eye to the metal box at the bottom, and use a regular squeeze fitting. But then you'd need to make the cord do a weird S shape as it leaves the box, so that the tension stays on the basket.

 

[Norcal]

Related question: can this be done (legally) for 220v as well? How about 3 phase 220?

I am going to be moving most of my woodworking tools into my garage, and the majority is 220v, with about half being 3 phase. "Regular" 220 plug on the single phase, twist-lock plug on the three phase stuff.

Yes, yes, but none of those voltages exist in the USA, & the 4 square boxes shown are not kosher for the use, a cast iron or aluminum FS or FD box would work, because they have a cast hub, but a common "bell box" would not. Boxes for pendant mounting are made but are very expensive.

A "Regular" 220 plug is shown in the link below.

https://www.iec.ch/worldplugs/typeF.htm.

 

[rlitman]

Yes, yes, but none of those voltages exist in the USA, & the 4 square boxes shown are not kosher for the use, a cast iron or aluminum FS or FD box would work, because they have a cast hub, but a common "bell box" would not. Boxes for pendant mounting are made but are very expensive...

No argument from me on the voltages. I just wasn't going there.

But I have here quite a number of UL Listed pendant boxes factory built out of stamped steel. Yes, a cast FS box is nicer, but I'm not sure about the necessity. I will say though that you don't want to suspend a pendant box from a knockout that has multiple sizes, unless you've knocked them all out.

 

[grounded-b]

Yes, yes, but none of those voltages exist in the USA,

220V (230V, 240V) is very common in the USA. 220V (230V, 240V) 3phase is also common ( Delta connected)

the 4 square boxes shown are not kosher for the use, a cast iron or aluminum FS or FD box would work, because they have a cast hub, but a common "bell box" would not.

A stamped steel box is fine to use with a Kellums grip connector. Done all the time.

A "Bell box" also would be fine, it has a cast hub BTW.

Steve

 

[PoorOwner]

Those FD boxes are expensive.

https://m.platt.com/Products.aspx?pid=164456


Will the fitting provide a snug fit into a bell box or FD box?
I recall when I used EMT on a bell box it just bottomed out, I think because EMT fitting is not tapered like IMC or RMC which are NPT threads.

 

[Norcal]

220V (230V, 240V) is very common in the USA. 220V (230V, 240V) 3phase is also common ( Delta connected)



Steve

Where is 220V still used in the US? Motors and welding equipment are rated for 230V but equipment with electric resistance heat is not unless it has a 208V rating at a reduced KW and 208V is not 220.

 

[PoorOwner]

I think these would be approved to use with stamped steel boxes, otherwise why have a lock nut, in fact it doesn't even have a hex you can turn against a pipe thread.

But I have seen another one with a pipe thread and hex face for a wrench.

 

[alfredeneuman]

I think these would be approved to use with stamped steel boxes, otherwise why have a lock nut.

It's approved with stamped steel boxes but at the top of the pendant drop, not the bottom. Stamp steel boxes, as Norcal said, cannot be used for the bottom.
Care must be taken with welded boxes not to use the welded sides for cord drops, because they could fail. Either use the folded sides for support or a drawn box.

Kellems grip with a loop to hang it from a hook is called a bus drop grip, and only bus bar drops for cord may take advantage of it because by Code they can be used up to 8' away from the bus bars. (They're commonly used for things other the purpose intended, but it violate the listing requirements).
Pendant drops for machines and receptacles should be directly above the workspace.

 

[gungatim]

al cu

 

[Norcal]

Cord reels can be very limited if wanting to go beyond 15-20A even the mind numbingly expensive ones, ran into that when trying to set up some 30A 480V welder drops some years ago. But cord reels are a nice way to do things if one can afford them.

 

[rlitman]

Also, cord reels should be completely unwound if you want to use them near their current ratings. Otherwise the interior winds of cord can overheat.

 

[mvusse]

Yes, yes, but none of those voltages exist in the USA, & the 4 square boxes shown are not kosher for the use, a cast iron or aluminum FS or FD box would work, because they have a cast hub, but a common "bell box" would not. Boxes for pendant mounting are made but are very expensive.

A "Regular" 220 plug is shown in the link below.

https://www.iec.ch/worldplugs/typeF.htm.

Okay, so we are being literal. Nominal voltage here (in the USA) is 240V, but everyone still calls half of it "110" even though it is actually 120.

The "regular" 220V plug you show is what we used in the Netherlands. IIRC the power there is 380V 3 phase, which makes ground to hot about 220V. But I have not been there since 1987.

I have 240V single phase coming into my garage. 3 phase comes from a 15HP start / 45HP run rotary phase converter.

 

[Phantomd]

I work in industrial maintenance. I've worked in entire facilities with 40' ceilings with suspended boxes with the "Chinese finger trap" type cord grips on SOOW cord.

I order my SOOW cord from a local wire distributor (paid $1/foot for 12/3 two weeks ago, without any special pricing) much cheaper then sourcing at big box stores. They ship me whatever length I want and it's still much much cheaper then H.D.

These cord grips you can get from McMaster Carr (amazing resource for parts) https://www.mcmaster.com/catalog/125/912


And you guys bickering about voltage... wow. My last facility was 220v 3phase because it was delta wired like grounded-b mentioned.

 

[grounded-b]

Those FD boxes are expensive.

https://m.platt.com/Products.aspx?pid=164456

Look for an FS box, they are a little shallower ( and cheaper ). D stands for "deep", S is "shallow"

Will the fitting provide a snug fit into a bell box or FD box?
I recall when I used EMT on a bell box it just bottomed out, I think because EMT fitting is not tapered like IMC or RMC which are NPT threads.

Reverse the locknut, and put it on the outside of the hub. Use it as a "jam" nut

 

[6PTsocket]

We had them hanging at work. I don't recall them being thick so they were probably SJ. We used them to plug in vacuum cleaners to clean the machine they hung over after a run. We only had a single 3 wire cord receptacle on the end, no box, and a Kellums only at the top. As the vacuum cleaners and other tools that were plugged in were portable the drop was constanly pulled in various directions. I never saw one fail. A drop to a stationary tool should be no problem.

Sent from my SM-G900V using Tapatalk

 

[alfredeneuman]

We only had a single 3 wire cord receptacle on the end, no box, and a Kellums only at the top.

A single cord receptacle is called a connector body.
The cord is provided with strain relief by means of the clamp on the end.

EDIT: Methods other than Kellums grips that are suitable for use as strain relief include fittings with glands in them that grip the cord tightly, and even 2 screw connectors

 

[PoorOwner]

Hi, bringing this back up. The grips and boxes are going cost alot, my requirement is to have the plug above my head level, above the machine, it does not need to swing freely.

So I am thinking, if I fastern a piece of lumber or unistrut perpendicular from the ceiling.
and have the EMT turn 90 degrees down, can I have a receptacle box at a height?

The unistrut 90 degree angle bracket is made of 1/4" steel.

(I have not found any way to run EMT same direction as the unistrut, do you use a single hole stand off and a 1/4 bolt)

 

[Slowgsr]

Sure that will work. Angle bracket to ceiling, drop the strut using 3/8 spring nuts to the angle, then run conduit down the strut using 1/4 spring nuts and 1/4 20s with a fender washer and stand offs. Downside is having these rigid drops all over. Requires lots of bits and pieces, all of which I have in my van. Id also have strain relief stuff, but I don't stock cabtire in my truck... Only ac90, but yeah. Electrical material is $$$.

How high is your ceiling? Could just mount twist locks on the deck and make yourself up a cord and let it hang.... The twist lock ends and receptacles can add up too.

 

[PoorOwner]

Sure that will work. Angle bracket to ceiling, drop the strut using 3/8 spring nuts to the angle, then run conduit down the strut using 1/4 spring nuts and 1/4 20s with a fender washer and stand offs. Downside is having these rigid drops all over. Requires lots of bits and pieces, all of which I have in my van. Id also have strain relief stuff, but I don't stock cabtire in my truck... Only ac90, but yeah. Electrical material is $$$.

How high is your ceiling? Could just mount twist locks on the deck and make yourself up a cord and let it hang.... The twist lock ends and receptacles can add up too.

Ceiling is 10.5 ft. I think the cord is 6-7 feet long. I think a suspended box is still better than a dangling extension to reach the ceiling. I may make the box downward facing.

 

[PoorOwner]

Looks like the machine cord can only reach about 6 feet tall, so it would infact need to be suspended with cord and not with a strut.

So what I got now:

SOOW cord 10'
FD box 3/4" cast iron, single gang "dead end"
special single gang receptacle cover made for FD box. (not sure what else I could use)
Cord relief with mesh grip by leviton


Grip with "loop" for ceiling cord
generic cord relief for ceiling box
metal box for ceiling, cord will be using the folded and not welded side.

 

[tonyciambrone]

Akshully by my measurement it is 122.3VAC so 120V is incorrect also *pushes up glasses*

 

[PoorOwner]

You can do it if the cable is thick enough. They also make these "finger traps" that take the stress off where the wire enters the box. I am not sure where you would buy one though.

How does this actually grip the wire? Does the mesh hold the cord on with a lot of friction?

 

[rlitman]

How does this actually grip the wire? Does the mesh hold the cord on with a lot of friction?

Yes, it's a Chinese fingercuff. The mesh squeezes more tightly as you pull on the wire.

 

[Norcal]

How does this actually grip the wire? Does the mesh hold the cord on with a lot of friction?

But it’s not code compliant to use a four square/1900 box like that.

 

[PoorOwner]

But it’s not code compliant to use a four square/1900 box like that.

I got this box

So do I really use a lock nut on the outside as a jam nut? That will decrease engagement of threads.

Is the fitting going to tighten into the hub thread like a NPT pipe?

 

[alfredeneuman]

Look at the threads on the Kellems grip. I think they are NPT threads.
Gland connectors could be either.
2 screw connectors have straight threads.
None of them will need a locknut if they're sufficiently tightened

 

[PoorOwner]

OK I got my stuff and it does have a tight pipe thread, so it is not going to come loose

One concern now I weighted the fitting, box, and cover it is 2.75 lbs.
The box and cover is made of cast iron. The weight is just a bit more than I thought it would be.
Mine is FD, 2.34lbs If it was FS it would be 1.96 lbs. I am thinking if you walked into it, it could hurt.

I have ordered SOOJ 12/3 cord with .59" diameter, it's a thick one, hopefully all will work well.

Is there an aluminum version of these boxes?

 

[Norcal]

OK I got my stuff and it does have a tight pipe thread, so it is not going to come loose

One concern now I weighted the fitting, box, and cover it is 2.75 lbs.
The box and cover is made of cast iron. The weight is just a bit more than I thought it would be.
Mine is FD, 2.34lbs If it was FS it would be 1.96 lbs. I am thinking if you walked into it, it could hurt.

I have ordered SOOJ 12/3 cord with .59" diameter, it's a thick one, hopefully all will work well.

Is there an aluminum version of these boxes?

Yes, there is.