I think I’ve found a potential design flaw in an extension cord. It allows you to plug in the hot blade, while leaving the neutral blade out and exposed. Obviously you shouldn’t try and use the cord like this, but is this actually safe, as in you won’t get a shock from touching the exposed pins?

It seems like I could complete a circuit to ground by touching the exposed neutral blade, which obviously I don't think would be great for my health.

I'm in Canada, the outlet it's plugged into is wired correctly, and there's no GFCI on the circuit.

plug (female view) plug (male view)

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    Why would you want to connect a cord this way? – Jim Stewart Jul 29 '19 at 16:28
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    I don't want to. It's not useful, but it's also really easy to do, which led me to wonder if it was considered safe (or perhaps a design flaw). – mrb Jul 29 '19 at 16:32
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    You should edit the question to clarify at the beginning that the cables are connected in this way to demonstrate a potential safety problem for the purposes of investigation, and are not connected to power. (They are not connected to power, right? :-)) Some commenters and posters seem to think you want to do this for some reason, which you clearly don't. – cjs Jul 30 '19 at 1:16
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    Site note that may be interesting to some people: these kinds of connectors are illegal in New Zealand. Sockets must be designed so that you can't fit a plug in this way (as the disconnected pins will bump into the plastic around the socket). – user253751 Jul 30 '19 at 5:14
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    (I meant "side note" of course, not "site note") – user253751 Jul 30 '19 at 10:12

No. In this condition, the exposed plug blade will be deadly.

Every load connects hot to neutral. It does so through some level of impedance, but that impedance is not enough to protect you from shock.

If you have a GFCI/RCD device somewhere protecting this load, that will intervene to prevent injury in this case.

One detail: Current wants to return to source, not ground. For man-made mains current, source is the supply transformer, and hot power is seeking neutral. It will be happy with ground, because back in the main service panel there is a neutral-ground equipotential bond connecting them, so it will go via ground to get back to neutral.

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  • I am not convinced that a GFIC would protect you in this case. The current will return through you and the so-called neutral. A GFCI measures that the amount of current 'entering' from Hot is in fact 'exiting' via neutral, the assumption being that if it not then it is going to ground, possibly through you. In this case the current would not go to ground, and the GFCI would not trip. If someone believes I am incorrect, please explain why. Or plug this into a GFCI and try it. I'll wait here. – UnconditionallyReinstateMonica Jul 30 '19 at 19:50
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    @mickeyf because you don't have access to neutral. You have access to ground. Neutral is a conductor and is as guarded as hot. Also, diy.se is a nicer place... we're not salty like SO, leave it there... – Harper - Reinstate Monica Jul 30 '19 at 20:03
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    Of course - you are correct. Current goes through hot, through the load, through me, and to ground. Neutral is way back upstream in this case. I just saw that blade in mid air and didn't think it through. – UnconditionallyReinstateMonica Jul 30 '19 at 20:13
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    GFCIs/RCDs should be regarded as supplementary protection to hopefully save your ass if a bunch of other stuff has gone wrong. Live conductors should still be regarded as dangerous even if they are behind a GFCI. – Peter Green Jul 30 '19 at 23:15
  • I'm afraid your depiction of the current's "desires" is far from accurate. Difference in charge will generate electric current through a conductor, whether the second point is somehow connected to the source or not. – IMil Jul 31 '19 at 13:33

This is absolutely NOT safe. There is actually a part of the NEC to help with this type of problem - tamper resistant receptacles. That doesn't address exactly the same situation - extension cords are functionally the same as receptacles but practically speaking a bit different and don't normally (ever?) have tamper resistant sockets. But a tamper resistant receptacle prevents you from inserting only hot or neutral - you have to insert them both at the same time.

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    Actually, a tamper resistant receptacle prevents you from inserting any part of the plug at all - that's why they are so safe :) – Michael J. Jul 30 '19 at 21:42

You might also notice that you have plugged the hot blade into the return socket! Whatever were you thinking? The reason that "blob" of material is part of the black receptacle is to ensure that you plug in "right side up" , with the ground pin in the ground receptacle.

Don't be a Darwin Award candidate.

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    In the photo in the question, the hot blade is plugged into the hot socket. – prl Jul 30 '19 at 1:00
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    "Don't be a Darwin Award candidate." The poster clearly did this only as a demonstration of a flaw in the connector design. Investigating potential safety flaws is the opposite of being a Darwin Award candidate. – cjs Jul 30 '19 at 1:12
  • +1 for the last sentence – dalearn Jul 30 '19 at 2:15
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    What is the danger in connecting hot to the return socket? – clemisch Jul 30 '19 at 14:35
  • @CurtJ.Sampson I can't see the edit history -- quite possibly I missed those 2 words. So far as "super absolutely safe" connector design goes, I appeal to the authority, aka YCFS We've all seen cords where someone cut off the ground pin to be able to connect, and similar bad-news hacks. – Carl Witthoft Jul 30 '19 at 14:40

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