Long extension cord

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jap

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Electrician
I was having a conversation with an Electrician who wanted to make a 250' extension cord for a mobile seamless gutter machine 13 amps 120v. He has a 250' roll of #8 3c SO cord that was provided by the owner.Is there anything wrong with putting a junction box on both ends of the #8 cord and coming out with
12/3 cord with a male on one end and a female on the other?
He was saying that if the wire size was not the same throughout the length of the cord that Voltage drop would still be an issue for the #12. I had to disagree stating that the #12 was good for at least 13 amps and the connection onto the #8 would be fine. Was I wrong?
 
jap said:
I was having a conversation with an Electrician who wanted to make a 250' extension cord for a mobile seamless gutter machine 13 amps 120v. He has a 250' roll of #8 3c SO cord that was provided by the owner.Is there anything wrong with putting a junction box on both ends of the #8 cord and coming out with
12/3 cord with a male on one end and a female on the other?
He was saying that if the wire size was not the same throughout the length of the cord that Voltage drop would still be an issue for the #12. I had to disagree stating that the #12 was good for at least 13 amps and the connection onto the #8 would be fine. Was I wrong?
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a junction box will be an issue, why not just use cord caps on each end of the cables?
 
J-boxes are not listed for that type of use.

What is the diameter of the cord? Maybe some manufacturer produces cord caps what will accept that size.
 
Voltage drop in the #12 sections would not be a problem. But how long will this cord be in use? You can't use portable cords as a replacement for permanent wiring.
 
charlie b said:
Voltage drop in the #12 sections would not be a problem. But how long will this cord be in use? You can't use portable cords as a replacement for permanent wiring.
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My guess is it's going to be rolled up at the end of every day. They need to get power from the home to their trailer when it's on the site.
 
jap said:
I was having a conversation with an Electrician who wanted to make a 250' extension cord for a mobile seamless gutter machine 13 amps 120v. He has a 250' roll of #8 3c SO cord that was provided by the owner.Is there anything wrong with putting a junction box on both ends of the #8 cord and coming out with
12/3 cord with a male on one end and a female on the other?
He was saying that if the wire size was not the same throughout the length of the cord that Voltage drop would still be an issue for the #12. I had to disagree stating that the #12 was good for at least 13 amps and the connection onto the #8 would be fine. Was I wrong?
Click to expand...

Seems like a reasonable approach, but a safety inspector might object to a worksite use of an extension cord that is not lighted and does not have a GFCI.

As another poster mentioned it won't make the arbitray 3% VD rule of thumb, but it should work OK.
 
hm, thats an interesting one. I think you will have to go with a Pin and Sleeve connector for the 8/3. The terminals on all the normal straight blade and 20a twistlock connectors are only for up to #10.

Maybe you could make up the ends of the cable with a 3' tail of 12/3 SO, and use a 1" conduit body for the splice and transition. How are you going to make the physical connection though? Wirenuts dont really play nice with the finely stranded wire in the SO cable.

Another thing to consider is GFI protection. I would put pin and sleeve connectors on the 8/3, make a 5-15 male to pin and sleeve female adaptor, and make up a male pin and sleeve to a box with a GFI receptacle in it.

Actually if it was me, I would sell the 250' 8/3 and purchase one of the little plastic lunchbox generators. I would much rather lug that around than a 250' hunk of 8/3.
 
wireguru said:
Actually if it was me, I would sell the 250' 8/3 and purchase one of the little plastic lunchbox generators. I would much rather lug that around than a 250' hunk of 8/3.
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I agree, I think he'd be better off with a little Honda inverter generator than a heavy chunk of cord. At least you can use the generator for other things.
 
petersonra said:
Seems like a reasonable approach, but a safety inspector might object to a worksite use of an extension cord that is not lighted and does not have a GFCI.
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Since Don has the former, I'll take the latter...

Since when are ext. cords required to have GFCI?
 
how about this

the idea presented in the OP is FINE and LEGAL and not a bad idea.

Voltage drop has nothing to do with whether you put the number 12 at the beginning or the end or in the middle or split it up in 3 places in between. all that matters is TOTAL RESISTANCE.

right now, total resistance is defined as the opinions coming from the members of this forum in regards to the OP


Do it

its fine

good idea

use a 'C' condulet as someone said. with type 'CG' cord grips to help with moisture. GFCI protection on an extension cord is not required as long as you are plugged into a GFCI outlet (although its not a bad idea)

and i dont know where the heck the lighted cord BS came from
 
I suggest having the GFI at the saw end of the cable, and connect it to a non gfi receptacle at the house. With 250' of #8 I bet you will be tripping the gfi.

I had suggested the C coudulet, but come to think of it I seem to recall cramming an 8/5 into a 4P5W twistlock. You may be able to get the 8/3 into an L5-20 twistlock. I am going to look around for a piece of #8 and see if it fits in the terminal.

You could do a setup like this: 5-15 male to L5-20 adaptor -->250' 8/3 with L5-20 on each end --> bell box with GFI receptacle in it, 12/3 SO cable with male L5-20. This way the guy is forced to use the GFI at the saw end and cant just plug his saw into the ext cord.

I have a bunch of 12/3 SO cable with 20A twists on it and some of the GFI boxes like I mentioned. Comes in handy all the time.
 
wireguru said:
I suggest having the GFI at the saw end of the cable, and connect it to a non gfi receptacle at the house. With 250' of #8 I bet you will be tripping the gfi.
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It is my understanding that the OSHA rules require GFCI protection for both the tools and the supply cord. The following is from an OSHA interpretation letter.
Section 1926.404(b)(1)(ii) requires all 120-volt, single-phase, 15- and 20-ampere receptacle outlets on construction sites, which are not a part of the permanent wiring of the building or structure and which are in use by employees, to have GFCI's for personnel protection. As explained in the preamble that was published when the final rule was promulgated, portable GFCI's are acceptable if they are connected to the receptacle outlet in use. (See page 55702, second column, first paragraph, last sentence of the attached Federal Register notice.) If a group of extension cords is connected in series, the first receptacle outlet in the series must be connected directly to the GFCI, because the rule requires all covered receptacle outlets to have protection. In this way, all receptacle outlets in the group of cords would have GFCI protection. (Note: If an extension cord is plugged into a permanent receptacle outlet, the employer should be advised to install the portable GFCI at the permanent outlet, rather than at the receptacle outlet at the end of the cord set.)
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I don't think there is any professional looking, long lasting, easy to handle way to do this using metal boxes at the end of cords. Cords should have cord caps on them, not boxes.

I doubt you will find standard 20 amp cord caps that will handle 8 AWG cords, for that reason I recommend using a 20 amp locking pin connector. No they are not cheap but they are the right part for the job.

Check out this catalog,

http://www.meltric.com/artwork/pdfs/2008-catalog/2008-ds.pdf


you can get 20 amp 125 volt cord caps that will handle 8 AWG. Of course you would need to make some short 12 AWG adapter cords to change from pin connectors to standard NEMA 5-15 devices.

I would also break up that 250' of 8 AWG cord into at least two pieces and three pieces would be better as 250' of 8/3 cord is going to be a bear to handle in one section.
 
Thanks for all of the replies.
Sometimes these threads get way off base from what was originally asked.
This one hung right in there.
The issue with the cord was not being able to terminate the large cord into the small cord caps. Thats why the transitions were needed.
Thanks again.
Jap
 
petersonra said:
Some places now want extension cords used outside on constuction sites to be illuminated. i guess so you can see the end.
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The only reason to have an illuminated cord end is to be able to tell whether the other end is plugged in and you have power available. If it's too dark to see a cord cap laying on the ground, it's too dark to see the entire cord, or anything else, laying on the ground. And that means it's too dark to work safely.
 
don_resqcapt19 said:
It is my understanding that the OSHA rules require GFCI protection for both the tools and the supply cord. The following is from an OSHA interpretation letter.
Click to expand...

I could be completely off here, but I was thinking along the lines of temporary power for fairs and such where the GFI can be provided at the utilization point.

Bottom line is, if the GFI manufacturers say not to use more than 250' of cable as the GFI will trip, how do you protect the entire cable?
 
iwire said:
I don't think there is any professional looking, long lasting, easy to handle way to do this using metal boxes at the end of cords. Cords should have cord caps on them, not boxes.

I doubt you will find standard 20 amp cord caps that will handle 8 AWG cords, for that reason I recommend using a 20 amp locking pin connector. No they are not cheap but they are the right part for the job.

Check out this catalog,

http://www.meltric.com/artwork/pdfs/2008-catalog/2008-ds.pdf


you can get 20 amp 125 volt cord caps that will handle 8 AWG. Of course you would need to make some short 12 AWG adapter cords to change from pin connectors to standard NEMA 5-15 devices.

I would also break up that 250' of 8 AWG cord into at least two pieces and three pieces would be better as 250' of 8/3 cord is going to be a bear to handle in one section.
Click to expand...

I had also suggested this with pin and sleeve connectors, but by the time the guy buys all the connectors, he could just dump the cable and get a honda inverter generator.

You should be able to get the Leviton 20a 125v 2P3W pin and sleeve connectors for around $50-$60ea if you have a good dist.
 
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