The Extension cord from Hell

The Extension cord from Hell
How to build a hybrid extension cord/outlet strip.

DANGER: This project involves household outlet voltage. DO NOT ATTEMPT IF YOU ARE NOT FAMILIAR WITH 120V HOUSEHOLD WIRING.

When the project is completed you have an adaptable extension cord. I used 5 outlet boxes, you can use as many or as few as you want, just change the length of the cord and parts count accordingly.
 
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Step 1Required Tools

Required Tools
To build this cord you will need:

A set of wire cutters
A wire crimper
A wire stripper or knife (or both)
A small and large flat blade screw driver
Pliers (needle nose or regular) (not pictured)

To test this cord you will need:
A Digital Multi Meter (not pictured)
An Outlet Tester (not pictured)
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46 comments
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Aug 1, 2010. 4:23 PMtheewz says:
Could I use standard house wiring then add a three prong extension cord end? The wire is on sale here for 2$ a meter.
May 31, 2011. 11:27 AMelco_chan says:
You could it will just be less flexible.
Feb 16, 2011. 12:10 PMEvilMarker says:
That is crkt m16 do I get a prize?
Jan 4, 2009. 10:02 PMjustible says:
Even if you had large guage wire, the breaker for the outlet you plug into is likely not rated for the kind of pull an outlet mess like this *could* attempt.

And the *wiring in the wall* between the outlet and the breaker would *also* not be rated for the enormous pull of a cord like this. This thing will start a fire for someone, somewhere.
Aug 22, 2010. 7:27 PMTHE_GEEK2007 says:
Outlets do not pull any amps when they are not being used. Even if all of these were plugged into the wall, but nothing was plugged into them, there would be absolutely no usage at all. Also, the wiring between most outlets in your home is probably 14 gauge wire, just like the extension cord this person used.
Feb 15, 2011. 5:18 AMludionis says:
The concern is that standard 14 gauge wire is rated for 15 amps. If you have this many sockets, generally, you're going to be using some/most/all of them, possibly exceeding the 15 amp rating. Also, bear in mind MOST outlets are not on isolated circuits, generally all the outlets from a room or several rooms are tied together, facilitating to potential overload.

General use extension cords are 16 gauge stranded wire, which will support even less. More likely a tripped circuit breaker before a fire, but fire is always a possibilty, especially with the on/off switch.
Feb 15, 2011. 6:06 AMTHE_GEEK2007 says:
Even if it exceeds the 15 amp rating, it would just trip the breaker anyways.
Oct 5, 2008. 5:55 PMJamesHolden says:
i would strongly consider adding a circuit breaker at the end that plugs into the wall. it would save you from costly problems down the road. i would also use plastic box's, if a wire came undone it would be a bit safer. and ofcourse, always make sure that cord is the only thing plugged into the circuit you're using. or atleast the only thing with high load devices on it (anything larger than a 100w bulb)
Jan 15, 2011. 8:24 AMstevie1 says:
about the plastic boxes... i dont know about his plugs but the majority of plugs i have used in projects in the last 4 or 5 years have had the ground screw/terminal on the plug attached to the tab that the screw goes through to hold the plug to the box, so the box automatically becomes grounded as soon as the plug is installed. Or if the ground is hooked to the box then the ground
hole(s) on the plug become grounded.
Jan 15, 2011. 8:09 AMstevie1 says:
here's some pics of my version...
50 feet of cable left.jpgbrandons end.jpggroup shot.jpgmavericks box.jpgmy box.jpgwhitty's box.jpg
Jan 10, 2011. 2:34 PMstevie1 says:
nice ible! i plan on making a cord like this for my band, only with a 12/3 extension cord that i bought at costco wholesale yesterday. 100 feet for 45 bucks.
Oct 13, 2009. 5:46 AMmuttyfutty says:
Nice, but isnt this a bit of, erm... Overkill?


Nov 5, 2010. 1:21 PMkill-a-watt says:
better to overkill then to have to bother to kill it over again.
Nov 5, 2010. 1:19 PMkill-a-watt says:
Nice.

A few points:

I found plenty of used outlets (mostly painted over) at the local Habitat for Humanity ReStore. They were 25 cents each.

The outlets could be free if you were changing out previously panted over outlets.

(I really hate it when people paint over outlets. Remove the cover, and mask with blue tape, people!)

By code, you need to also attach the ground to the boxes, then connect all the grounds together with a wire nut.

You can skip grounding the box if you instead use "special outlets" for this purpose, or switch to plastic handy-boxes. If you go plastic, please use plastic covers too.

If you have scrap armored cable or scrap conduit, you could use that between the boxes. At one point when the economy was good, you could find this in dumpsters all the time. Later, as copper went up, they took out the scrap copper wire, later than that they also kept the alumum sheathing to recycle. you can still find plenty of steel boxes, steel wall studs and sometimes outlets and switches too.

Something like this mounted to the underside of a desk would be great. I have something like this under the shelf in my garage.
Sep 20, 2010. 5:59 PMwsanriv says:
the 2 plugs are fine if you have all you wall sockets polarized, other wise a bad connection will leave a very dangerous short circuit.
Jan 25, 2009. 7:01 PMg.laughlin says:
extension cord from 7734 wow, I have one like that from the orange box store not as many outlets but there are little green LEDs in the outlets, for plugging in the dark. creating major envy on many a job site.
Junior electrical engineer's your 10 outlets per circuit rule is falsely based on NEC 220.14(I) this is only for calculating the total load of a building (any type) and has nothing to do with how many outlets can put on a circuit,that has every thing to do with the building wiring and the circuit over-current device.
And the GFCI every thing attitude. If you check the NEC 210.8 only in places where the user or equipment may come in contact with WATER, Bathrooms, Kitchens, Rooftops or Outdoors is GFCI protection required. so for all DJ types NEC 640.10(A&B) if your audio equipment is with in 5' of water you need GFCI protection, IT geeks, the last thing u want is a GFCI(power loss = Information loss), but you need to be Properly GROUNDED NEC 645.15

and never let a fool play with your tool
Mar 30, 2009. 7:48 PMlightfusegetaway says:
So you're saying I can't run this between my tub and toilet to power my 7.1 Dolby surround shower system? Awww, man.
Jan 3, 2009. 9:54 AMIW5 Industries says:
how did you manage to steal that from satin and make it safely out of hell or,....your a demon!!!!!!!!!! lol jk
Sep 8, 2008. 7:42 AMgmjhowe says:
Would you not be best using a 'cheat' It wires up so that you plug into two outlets at the sametime, allowing a better daisy chain. We used one alot when doing gigs.
Sep 10, 2008. 10:30 AM0.775volts says:
so that it can plug into two outlets? you mean ,like two male plugs on the end? that is absurdly dangerous. if you need that much power, you need more than one pit quad, and probably on seperate circuits.
Sep 10, 2008. 2:11 PMgmjhowe says:
Thats right, we used it to run loads of equipment off when doing gigs, eg mixing desk amps, large speakers. It actually very safe, and safer than trying to run off one outlet. Normally the cheat is the only main thing plugged into the power in the building.
Sep 10, 2008. 4:23 PM0.775volts says:
yeah, that's really, really unsafe. first off, you have a live male plug, which is something that should never happen. up until now you you've been lucky, and haven't crossed legs by trying to use such a piece of equipment, which would either give you 240 v down the line, or just shunt massively when you plug the second connector in. Like i said Using ANYTHING with two male plugs on it is extremely unsafe, and should not EVER be attempted. if you need more current, buy a second extension cord and read up about load balancing. why would you risk losing all of your equipment for the price of a decent extension cord? I just doesn't make sense,.
Sep 11, 2008. 12:05 AMgmjhowe says:
hmm, you don't seem to be reading me right - This is a professional level piece of equipment. You right with the two live male plugs - you have to be very careful, and basically plug and unplug at exactly the same time. But other wise, its alot safer than your making out. The cheat method is alot safer for the equipment, and is used often for people doing gigs in environments without dedicated power sockets e.g. it came in very usefull when playing at derby cathedral. Any more info than that and im going to come undone, as thats the most i know about it, if you want any more info, i will get my friend (whom uses/owns it) to explain more!
Sep 11, 2008. 8:22 AM0.775volts says:
Yeah, ask your friend for info. if it's an actual product, I'd like to see photos and/or a product link. I could see something like this being used with a 30/30 jack or something like that to support more than one phase of power (ie two legs down a four conductor cable. I've used 30/30 breakouts in the other direction. the problem with using something like that is that you would have to know which phases were which and how you were connecting to them.
Sep 11, 2008. 9:00 AMgmjhowe says:
yeah, you see, i didnt get a word of that, it didn't make one bit of sense! i will ask him next time, all i remember is it went into like a triangular box with power outlets on it...
Sep 11, 2008. 10:16 AM0.775volts says:
ahh. not to be nit pikcy or anything, and I can understand how the difference may not be apparent, but that clarifies things. the solution you suggested here is not the same one that you;ve used in the past. the one you proposed is potentially deadly, whereas you used something different, sounds like a costom made distro or something,.
Sep 11, 2008. 2:23 PMgmjhowe says:
yes something like that, there actually going to use it at a gig tomoro!
Sep 10, 2008. 10:27 AM0.775volts says:
we usually build out our pit quads (that's what this is) with 10/3 sjoow. even if you're just powering stand lights, it still adds up. I would recommend plastic boxes if you can find them, but use what you've got, I've seen more metal pit quads than plastic ones. also, if you want to adapt this for pit/backline use, three feet between boxes is pretty nice(though if you move it around alot it doesn't really matter what the span is)
Sep 7, 2008. 9:21 PMsdallesasse says:
It would be a good idea to put a GFCI as the first outlet and feed the rest off of the load side. This would allow you to place it anywhere without the danger of a shock due to water. Also I would use # 10 AWG for the cord. #14 only allows 15 amps, #12 20 and #10 30. This would give you a large buffer in case of overload.
Sep 7, 2008. 7:48 PMdefiant1 says:
Wow, definitely check the wattage on EVERYTHING plugged in and do NOT exceed the limits of whatever gauge cord you use. I would also recommend a 15amp fuse inline somewhere if you don't have any fire insurance. Remember, It's easy to make electricity go in a circle, a little harder to do it right, and safely. This might work great for Christmas lights though.
Sep 7, 2008. 7:21 PMguyfrom7up says:
Hell caught on fire, they returned the extension cord to neosensi. They went to court and satin lost. He was too cheap to put out the fire.
Sep 7, 2008. 4:49 PMjoejoerowley says:
Cool, but not the safest thing ever. I would do it still though.
Sep 7, 2008. 4:13 PMPlasmana says:
This is a good instructable! I might use this idea.. Thanks!
Sep 7, 2008. 9:58 AMKiteman says:
Twenty appliances? Plugged into one wall-outlet? I'll probably be able to see the smoke from here...
Sep 7, 2008. 4:05 PMPlasmana says:
Umm, no, 21!!!!!! Don't forget the end of the wire, there is a plug...
Sep 7, 2008. 11:58 AMHoopajoo says:
No kidding. My neighbor's house burned to the ground from an insufficient drop cord supplying a DVD player. With the amperage running through that cord, I bet it will burn you just to touch it. I would go with a 8 or 10 gauge cord and an inline breaker / GFCI as a minimal safety precaution.
Sep 7, 2008. 1:26 PMTheWelfareWarrior says:
not a bad instructable, the idea behind it is good too! as with what other people have said FIRE HAZARD... I wouldn't use powertools with it, maybe 1 or two but not anything bigger than a single skillsaw....
Sep 7, 2008. 12:46 PMzuixro says:
Wow, I was working on an 'ible just like this. Only I just put one box on an extension cord. At work we called them quad boxes. I liked them so much that I decided to build a couple for myself. I made mine pretty much the same way, only I didn't use spade connectors, I just made a hook of wire.
Sep 7, 2008. 11:36 AMzachninme says:
I understand people's concerns, but I understand you know what you're doing. Still won't hurt to put a warning about the amps ;-)
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Author:neosenshi