# Power drops in middle of shop



## running dummy

I've done that exact set up you explained. We would hit a box and use a kellum (strain relief) to hang the cord. You can get a connector with the cord relief right on the end. Worked out awesome, we even did a 100a drop. That was a big cord and the twist lock was immense!


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## pitapacket

running dummy said:


> I've done that exact set up you explained. We would hit a box and use a kellum (strain relief) to hang the cord. You can get a connector with the cord relief right on the end. Worked out awesome, we even did a 100a drop. That was a big cord and the twist lock was immense!


A google search for "Kellum strain relief" yielded perfect results. I hope my supply house has these on hand. So it looks like you just pop out of the side of a box with the kellum connector and SJO and drop down to the service location with a female twist lock. Great info. Thank you.


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## running dummy

We faced the box up and came out the bottom knockouts. Or face down with a blank and a knockout. 

If it was really critical I mounted strut and shot a laser to get the box perfect.


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## hardworkingstiff

Where is the strain relief located on the cord, near the top or do you slide it down the cord closer to the receptacle? 

How far can an SO cord support itself (in the vertical) before needing additional support? I don't know although I'm pretty sure there is one.


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## running dummy

hardworkingstiff said:


> Where is the strain relief located on the cord, near the top or do you slide it down the cord closer to the receptacle?
> 
> How far can an SO cord support itself (in the vertical) before needing additional support? I don't know although I'm pretty sure there is one.


It depends on the kellum. We used some that were right at the box, where others can be a little lower you just have to attach the relief to structure. 

I believe we used a SO cord that was rated for drops and had extra support integral to the cord


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## swissmiss177

We always come out the side or face of a box leave a loop go to the grip then down to twistlock. Works great!


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## NacBooster29

They make an attachment with a spring, you loop out of jbox. And leave a few feet and this kellum sits in the middle of cable. For added strain relief. You can add as many of these for support as needed.


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## MDShunk

I've probably done a million cord drops during my time as a factory electrician. I normally do them like this:


Set 4-square or other suitable junction box on bar joists with beam clamps or whatever
Come out of the side of the box with the rubber cord, about 1 foot horizontally along the bar joist
Make about a 1 foot diameter loop in the rubber cord and zip tie in three opposing spots. (This is the slack for the inevidable move left or right a smidge)
Slide cord drop grip over cord.
Connect cord drop grip to drawbar spring (picture below)
Hang drawbar spring from beam clamp or other suitable fastening device (eye bolt if wood)
Terminate plug cap on bottom end of cord at the required height.


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## MDShunk

If you want to get real fancy, at the plug end you can use a plug cap grip that has two eyelets. You disassemble the clamping part of plug cap and put it between the halves of the plug cap clamp and reassemble. Pretty bulletproof if you think the cord might get jerked on a lot.


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## MDShunk

running dummy said:


> I believe we used a SO cord that was rated for drops and had extra support integral to the cord


Yeah, that's the stuff you're really supposed to use. It's called "Bus drop cord". It has heavy plastic filler fibers inside. Some have Kevlar fibers. "Strain members", I think they're called. Some cord that is used for pendant controllers that will get jerked on a lot has a tiny stainless steel wire rope inside, and you're supposed to terminate it around a bolt inside the junction box at the top end, and around a clamping feature inside the pendant controller at the bottom end.


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## pitapacket

Tons of great and useful information. Thanks a ton. I'm looking forward to this for sure.


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## MDShunk

FWIW, if you don't have time to order drawbar springs from Grainger, and you want to use them, you can get them at the hardware store. They sell them for use on storm door wind chains and for use on porch swing chains.


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## pitapacket

MDShunk said:


> FWIW, if you don't have time to order drawbar springs from Grainger, and you want to use them, you can get them at the hardware store. They sell them for use on storm door wind chains and for use on porch swing chains.


This is going to work for me. What's your preferred method for attaching the SJO to the drawbar?


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## pitapacket

pitapacket said:


> This is going to work for me. What's your preferred method for attaching the SJO to the drawbar?


Just re read the post. I need the drop relief. Gotcha


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## kaboler

20 feet doesn't seem like much.


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## brian john

kaboler said:


> 20 feet doesn't seem like much.


Last time I looked it was more than 19' and less that 21'. Seem right to you?


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## amptech

I have always done something like what MD described but used a Sky-Tie SH-50 and spring at the top. They are made by Adalet. Went through cases of them in a factory doing drops from a 28' ceiling.

http://bonanzleimages.s3.amazonaws.com/afu/images/1490/8431/e7bb_1_sbl.jpg


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## MDShunk

amptech said:


> I have always done something like what MD described but used a Sky-Tie SH-50 and spring at the top. They are made by Adalet. Went through cases of them in a factory doing drops from a 28' ceiling.
> 
> http://bonanzleimages.s3.amazonaws.com/afu/images/1490/8431/e7bb_1_sbl.jpg


Appleton makes one very similar that I occasionally used for cord that got into the very heavy gauges. I'll see if I can drag up a picture someplace.

EDIT:


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## amptech

MDShunk said:


> Appleton makes one very similar that I occasionally used for cord that got into the very heavy gauges. I'll see if I can drag up a picture someplace.
> 
> EDIT:


Does that actually clamp the cord between halves? Or do you just hang the cord through it? Adalet makes bigger ones with heavier springs. We used some for 6/4 SOOW for welder drops.


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## Loose Neutral

MDShunk said:


> Yeah, that's the stuff you're really supposed to use. It's called "Bus drop cord". It has heavy plastic filler fibers inside. Some have Kevlar fibers. "Strain members", I think they're called. Some cord that is used for pendant controllers that will get jerked on a lot has a tiny stainless steel wire rope inside, and you're supposed to terminate it around a bolt inside the junction box at the top end, and around a clamping feature inside the pendant controller at the bottom end.


I just demo'd some of that stuff . They were using it for travel cable for an elevator.


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## CanadianSparky

MD the reason you use the springs so if it gets pulled? I usually just use a kellems hanger with no spring.


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## MDShunk

CanadianSparky said:


> MD the reason you use the springs so if it gets pulled? I usually just use a kellems hanger with no spring.


Yeah. The spring is an optional thing. Your gut will usually tell you if it's likely to get pulled on. You can get as plain or as fancy with cord drops as you want to.


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## GEORGE D

So even with bus drop cord you should/must use strain relief of some sort? What if the cord supplied a machine that seldom got unplugged or messed with, would you guys still use something additional to cord grip connector? Reason I ask is I have a job coming up in future with roughly 60 of these drops, ceiling at roughly 12', what would you guys do? Oh and machines are 20-30 amps.


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## MDShunk

GEORGE D said:


> So even with bus drop cord you should/must use strain relief of some sort? What if the cord supplied a machine that seldom got unplugged or messed with, would you guys still use something additional to cord grip connector? Reason I ask is I have a job coming up in future with roughly 60 of these drops, ceiling at roughly 12', what would you guys do? Oh and machines are 20-30 amps.


Hang it from a Kellems grip. If you zip tie it to the bar joist as it goes from horizontal to vertical, in a year it will be bent in a hard 90 under its own weight.


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## 10492

IMO 



For a machine shop, I'd install feeders going to something lite, like Starline Bus duct. You can add disconnects and flexible cords where ever and when ever you want. The flexibility sells itself, in a machine shop enviroment with machines coming, going and moving around.

:thumbsup:


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## GEORGE D

Dnkldorf said:


> IMO
> 
> For a machine shop, I'd install feeders going to something lite, like Starline Bus duct. You can add disconnects and flexible cords where ever and when ever you want. The flexibility sells itself, in a machine shop enviroment with machines coming, going and moving around.
> 
> :thumbsup:


I do plan on bus duct, can the drops come straight out of bottom of discos or is further support required?


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## MDShunk

GEORGE D said:


> I do plan on bus duct, can the drops come straight out of bottom of discos or is further support required?


Use the Kellems grip that goes in the box knockout. You can use a gland type cord connector, but it doesn't take much of a tug to pull the cord through one of them. If you use a Kellems grip that goes in the knockout, you can swing on that cord like Tarzan, if you want to.


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## cdnelectrician

MDShunk said:


> Use the Kellems grip that goes in the box knockout. You can use a gland type cord connector, but it doesn't take much of a tug to pull the cord through one of them. If you use a Kellems grip that goes in the knockout, you can swing on that cord like Tarzan, if you want to.


Except if the disco has concentric knock outs, then I would not use a box connector kellems grip.


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## oldtimer

MDShunk said:


> Use the Kellems grip that goes in the box knockout. You can use a gland type cord connector, but it doesn't take much of a tug to pull the cord through one of them. If you use a Kellems grip that goes in the knockout, you can swing on that cord like Tarzan, if you want to.


As long as you are wearing a LOIN CLOTH. :laughing::laughing::laughing:


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## MDShunk

cdnelectrician said:


> Except if the disco has concentric knock outs, then I would not use a box connector kellems grip.


Fine point.


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## BBQ

MDShunk said:


> If you use a Kellems grip that goes in the knockout, you can swing on that cord like Tarzan,


If you space the cords out nicely you should be able to go from one end of the room to the other. :thumbsup:


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## BBQ

cdnelectrician said:


> Except if the disco has concentric knock outs, then I would not use a box connector kellems grip.


No guts no glory.


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## 10492

GEORGE D said:


> I do plan on bus duct, can the drops come straight out of bottom of discos or is further support required?


Some come out the bottom, mostly fused ones that I remember. 
The breaker disco's usually came out the side. 

So, the bottom outs, would have strain relief connectors.

The side outs, you could use a standard cord connector with no strain relief, and use a cord drop strain relief, supported by aircraft cable, directly above the target.

The disco's usually have a 1/2x3/4 KO. As mentioned above in reference to the concentric KO's, use the 3/4" KO, and always keep 3/4" strain reliefs in stock.


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## BBQ

I don't see permission to hang the cord directly from the switch.



There are also limits to how far you can swag the cord. 




> *368.56 Branches from Busways.* Branches from busways
> shall be permitted to be made in accordance with
> 368.56(A), (B), and (C).
> 
> *(B) Cord and Cable Assemblies.* Suitable cord and cable
> assemblies approved for extra-hard usage or hard usage and
> listed bus drop cable shall be permitted as branches from
> busways for the connection of portable equipment or the
> connection of stationary equipment to facilitate their interchange
> in accordance with 400.7 and 400.8 and the following
> conditions:
> 
> *(1)* The cord or cable shall be attached to the building by
> an approved means.
> 
> *(2)* The length of the cord or cable from a busway plug-in
> device to a suitable tension take-up support device shall
> not exceed 1.8 m (6 ft).
> 
> *(3)* The cord and cable shall be installed as a vertical riser
> from the tension take-up support device to the equipment
> served.
> 
> *(4)* Strain relief cable grips shall be provided for the cord
> or cable at the busway plug-in device and equipment
> terminations.


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## Awg-Dawg

At one shop I do work at, I run emt with the cable "sleeved inside" with grips attached to the emt then ran to the equipment.

I think that violates 3 of those 4. No?:001_huh:


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## GEORGE D

BBQ said:


> I don't see permission to hang the cord directly from the switch.
> 
> There are also limits to how far you can swag the cord.


Yeah, good call, I thought I had read that before but was hoping some way around that. I guess the best would be the standard strain relief that attaches to joist.


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## 10492

BBQ said:


> I don't see permission to hang the cord directly from the switch.













I'm guessing per manufacturers directions you can.


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## BBQ

Dnkldorf said:


> I'm guessing per manufacturers directions you can.


And I am saying I don't see the permission to do so, and yes we install Starline bus as well. :jester:


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## pitapacket

So much good stuff. Does anyone have pictures?


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## Beberoni

*Hanging Bus Drop cable*

Normally, we use a skytie and spring and attach it somewhere on the ceiling joists or perlins, and also use a Kellems grip strain relief.


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## CFL

running dummy said:


> I've done that exact set up you explained. We would hit a box and use a kellum (strain relief) to hang the cord. You can get a connector with the cord relief right on the end. Worked out awesome, we even did a 100a drop. That was a big cord and the twist lock was immense!


 
Ya, ya, I know the thread is old.

100a twist lock? Never seen one.:whistling2:


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## running dummy

CFL said:


> Ya, ya, I know the thread is old.
> 
> 100a twist lock? Never seen one.:whistling2:


Yea it was nuts. I remember it being a pain in the ass getting everything to lay in nicely on the end. I believe we set a 18"x18" jbox face up on strut and punched the bottom to land it where it needed to go. 

The place manufactured postal sorting systems and would test all of their new systems in this building. On one side of the (immense) building they had a whole service devoted to 50hz equipment. Really cool job to be on as an apprentice. :thumbup:


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## Bbsound

running dummy said:


> Yea it was nuts. I remember it being a pain in the ass getting everything to lay in nicely on the end. I believe we set a 18"x18" jbox face up on strut and punched the bottom to land it where it needed to go.
> 
> The place manufactured postal sorting systems and would test all of their new systems in this building. On one side of the (immense) building they had a whole service devoted to 50hz equipment. Really cool job to be on as an apprentice. :thumbup:


yeah I know this is an old thread also........

did you put the plug on the correct end of the cord?

Yes, it does matter which end.
No, it is not the same on both ends.


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## running dummy

Bbsound said:


> yeah I know this is an old thread also........
> 
> did you put the plug on the correct end of the cord?
> 
> Yes, it does matter which end.
> No, it is not the same on both ends.


I don't recall. 

It's been a few years since I terminated that one end...


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## CFL

running dummy said:


> Yea it was nuts. I remember it being a pain in the ass getting everything to lay in nicely on the end. I believe we set a 18"x18" jbox face up on strut and punched the bottom to land it where it needed to go.
> 
> The place manufactured postal sorting systems and would test all of their new systems in this building. On one side of the (immense) building they had a whole service devoted to 50hz equipment. Really cool job to be on as an apprentice. :thumbup:


 

What I meant was they don't make a 100 amp twist lock. It was probably a pin and sleeve device. I just wanted to point that out.


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