Code on portable cord drops strain releif

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Danaher

Member
Location
NC
Hello its been awhile since I have been here but remember the site from years ago, lots of great infomation here. Anyways I have a question concerning portable cord drops. I work in a factory where portable drops are made because the cells are moved frequently. When making a drop we use a strain releif to secure the cord at the point of drop 90 degree striaght down, when Fastening the strain releif to the building structure I use a tie wrap to secure it to a existing conduit pipe, building structure air line pipe what ever is excessible except fire sprinkler water pipes. I am being told this is wrong and that I need to put a tie wrap anround the pipe or what ever and then put a tie wrap thru the tie wrap and the strain releif then its not attached to the building, I hope this was not confusing..Others words one Tie wrap vs 2 tie wraps....Company I work at (NC) says 1 tie wrap is wrong I need to use 2... thanks
 

tom baker

First Chief Moderator
Staff member
NEC does not require or mention use of cable ties. If someone is telling you your method is wrong what do they cite for a reference?
Rules on portable cord are in Art 400
 

iwire

Moderator
Staff member
Location
Massachusetts
When making a drop we use a strain releif to secure the cord at the point of drop 90 degree striaght down, when Fastening the strain releif to the building structure I use a tie wrap to secure it to a existing conduit pipe,

I know you asked about the tie wrap but you are not supposed to be securing it to conduits.

300.11 Securing and Supporting.
(B) Raceways Used as Means of Support.
Raceways
shall be used only as a means of support for other raceways,
cables, or nonelectrical equipment under any of the
following conditions:

(1) Where the raceway or means of support is identified for
the purpose

(2) Where the raceway contains power supply conductors
for electrically controlled equipment and is used to support
Class 2 circuit conductors or cables that are solely
for the purpose of connection to the equipment control
circuits

(3) Where the raceway is used to support boxes or conduit
bodies in accordance with 314.23 or to support luminaires
in accordance with 410.36(E)
 

Danaher

Member
Location
NC
Here is a example I run a 120 volt line in rigid conduit and stop over the area it is supplying power too,I come out of a 4x4 box with a portable cord connector and fasten the strain releif to the conduit I just run so that it drops striaght down to the cell, the codes says this is not exceptable? Just trying to get a good understanding thanks
 

iMuse97

Senior Member
Location
Chicagoland
Here is a example I run a 120 volt line in rigid conduit and stop over the area it is supplying power too,I come out of a 4x4 box with a portable cord connector and fasten the strain releif to the conduit I just run so that it drops striaght down to the cell, the codes says this is not exceptable? Just trying to get a good understanding thanks

You understood the previous postings correctly. Conduit is designed to support the conductors inside it, not the ones outside it, and hanging from it. Your 4x4 needs to be mounted to something so you could attach your tywraps to that.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
I think the OP is asking if his cord and strain relief device can be secured directly to a building. The inference from using two wire ties, is that the first tie is attached to the building which means the second tie is not attached 'to the building'.
The word conduit may have become a distraction to the original question.
 

hurk27

Senior Member
When doing cord drops I have a specific way I do them, first I use a hook into a structure member or a beam clamp that is strong, with a hook, I always use a twist-loc receptacle at the top to keep it plugged in so vibrations wont let it fall out, and this also keeps them from removing them to be used as an extension cord and then loosing it, it also allow a quick way for them to remove the cord if a work station is relocated or done away with, the last place I made up 3 extra cords encase one was damaged.
Using a loop basket at the top installed about a foot from the T-L plug on the end, the cord I use is extra hard usage type with the strain fibers in it, for the bottom I use a malleable iron two gain box with a single hub (required by 314.23(H)(1) (I think) with a kellums grip to attach the cord to the hub, with a malleable two gain GFCI/duplex cover. all but about indestructible.
The trucking company garage I did a few years ago had a fork truck hang up on one of the receptacle box's and they said it lifted it off the floor about 6" but didn't even damage the drop, the hook at the top was bolted into a truss, but even then I was surprised that nothing gave or broke free, been using this method for a few years and yet to have one fail.

I would say if you are going to just use ty-raps then don't use a locking receptacle as if it ever gets pulled out you will want the receptacle to be able to be pulled free with out doing damage, I have never direct wired them into a box since it can do allot of damage if they get yanked on or catches on moving machinery, and might be an advantage to allow them to pull free if they can be caught on moving machinery, I'm sure if the above fork lift was much bigger it could have broke that truss the hook was mounted to, but luckily it lifted the fork lift instead, something larger might have brought the roof down, so a break free install might be a good idea?
 
Last edited:

Danaher

Member
Location
NC
You guys are correct, Example Start at panel box, run conduit to work area, mount a 4x4 box, come out of 4x4 box with a cord connector, then use a strain releif aka ( chinese choker) to suspend cord from ceiling striaght down to work table, Mount 4x4 box to table with a cord connector and mount receptacles in the this box, usually come out of this box using cord to multiple boxes with receptacle mounted in all boxes with cord connectors...Now when I support the chinese choker from the ceiling (A) I cannot ty wrap it to the existing conduit or any orther conduit but I can to the 4x4 Box if the box is secured to building Correct? (B) I was told we cannot use receptacle in the ceiling, which when I started here they did but they were striaght blade 110 plugs and could come out,so all were removed and started making drops with SJ cord to the table, now is it with in code to use twist lock receptacles in the ceiling, If so I still have the problem of finding a ty off in the ceiling that would let me drop striaght down vs an angle unless I put a support brace in the ceiling for the drop. I hope I explained this so you can better understand my situation and I really appreciates your opinions.....Sounds like I need to put support brackets (unistrut or angle iron with beam clamps) in ceiling to make my drops..Might even suggest going to twist lock in ceiling so we could just unplug cell move to new area then just plug it back in(ceiling). We do a lot of moving here...thank you for listening and appreciate your opinions on this...

When doing cord drops I have a specific way I do them, first I use a hook into a structure member or a beam clamp that is strong, with a hook, I always use a twist-loc receptacle at the top to keep it plugged in so vibrations wont let it fall out, and this also keeps them from removing them to be used as an extension cord and then loosing it, it also allow a quick way for them to remove the cord if a work station is relocated or done away with, the last place I made up 3 extra cords encase one was damaged.
Using a loop basket at the top installed about a foot from the T-L plug on the end, the cord I use is extra hard usage type with the strain fibers in it, for the bottom I use a malleable iron two gain box with a single hub (required by 314.23(H)(1) (I think) with a kellums grip to attach the cord to the hub, with a malleable two gain GFCI/duplex cover. all but about indestructible.
The trucking company garage I did a few years ago had a fork truck hang up on one of the receptacle box's and they said it lifted it off the floor about 6" but didn't even damage the drop, the hook at the top was bolted into a truss, but even then I was surprised that nothing gave or broke free, been using this method for a few years and yet to have one fail.

I would say if you are going to just use ty-raps then don't use a locking receptacle as if it ever gets pulled out you will want the receptacle to be able to be pulled free with out doing damage, I have never direct wired them into a box since it can do allot of damage if they get yanked on or catches on moving machinery, and might be an advantage to allow them to pull free if they can be caught on moving machinery, I'm sure if the above fork lift was much bigger it could have broke that truss the hook was mounted to, but luckily it lifted the fork lift instead, something larger might have brought the roof down, so a break free install might be a good idea?
 

iwire

Moderator
Staff member
Location
Massachusetts
When doing cord drops I have a specific way I do them, first I use a hook into a structure member or a beam clamp that is strong, with a hook,

That is a problem unless it is a bus duct.


400.8 Uses Not Permitted. Unless specifically permitted
in 400.7, flexible cords and cables shall not be used for the
following:


(4) Where attached to building surfaces

Exception to (4): Flexible cord and cable shall be permitted
to be attached to building surfaces in accordance with the
provisions of 368.56(B)
 

raider1

Senior Member
Staff member
Location
Logan, Utah
You guys are correct, Example Start at panel box, run conduit to work area, mount a 4x4 box, come out of 4x4 box with a cord connector, then use a strain releif aka ( chinese choker) to suspend cord from ceiling striaght down to work table, Mount 4x4 box to table with a cord connector and mount receptacles in the this box, usually come out of this box using cord to multiple boxes with receptacle mounted in all boxes with cord connectors...Now when I support the chinese choker from the ceiling (A) I cannot ty wrap it to the existing conduit or any orther conduit but I can to the 4x4 Box if the box is secured to building Correct? (B) I was told we cannot use receptacle in the ceiling, which when I started here they did but they were striaght blade 110 plugs and could come out,so all were removed and started making drops with SJ cord to the table, now is it with in code to use twist lock receptacles in the ceiling, If so I still have the problem of finding a ty off in the ceiling that would let me drop striaght down vs an angle unless I put a support brace in the ceiling for the drop. I hope I explained this so you can better understand my situation and I really appreciates your opinions.....Sounds like I need to put support brackets (unistrut or angle iron with beam clamps) in ceiling to make my drops..Might even suggest going to twist lock in ceiling so we could just unplug cell move to new area then just plug it back in(ceiling). We do a lot of moving here...thank you for listening and appreciate your opinions on this...

If you hard wire a drop a cord down to a fixed table and secure a 4X4 box to the table and install receptacles then IMHO this is a violation of 400.8(1).

Now if you used a receptacle on the ceiling then a twist lock cord end in the cord it would be code compliant provided that the cord is not secured to the building surface. (See 400.8(4))

Chris
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
If you hard wire a drop a cord down to a fixed table and secure a 4X4 box to the table and install receptacles then IMHO this is a violation of 400.8(1).

Now if you used a receptacle on the ceiling then a twist lock cord end in the cord it would be code compliant provided that the cord is not secured to the building surface. (See 400.8(4))

Chris

I always figure that if you can drop a cord down to the table, then you can drop a conduit down to the table. I'm sure they're going to say something about how they move the tables around a lot.
 

hurk27

Senior Member
If you hard wire a drop a cord down to a fixed table and secure a 4X4 box to the table and install receptacles then IMHO this is a violation of 400.8(1).

Now if you used a receptacle on the ceiling then a twist lock cord end in the cord it would be code compliant provided that the cord is not secured to the building surface. (See 400.8(4))

Chris

I agree with what Bob said, and what you have said, but I can't figure out why the NEC would allow the cord to pull directly on the receptacle and cord cap, but would not allow a simple hook so that the weight of the drop is not on the receptacle???

One of those things in the NEC that have not made sense to me, now we can twist the words around, and say its no more attached to the building hanging from the hook then it is hanging from the receptacle which is also attached to the building, but that would just lead to another 100 post thread :happyyes:
 
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