Is the ground hole on a household 110 volt electrical plug supposed to be at the top or bottom?

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  • 1 decade ago
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    The grounding hole on the household 110v electrical receptacle, not plug, is to be mounted with the ground hole on the top. In the household, this really doesn't make much difference, but in hospitals, it is part of the NEC (National Electrical Code). The reason being is, especially in hospitals, they are dealing with the Oxygen in the rooms, and we don't want a catastrophic fire to be started. At any rate, if the 3-prong electrical plug would happen to be pulled out of the receptacle where the prongs are exposed, and some type of metal equipment would happen to accidentally get dropped, the grounding lug of the plug would be the 1st thing that this dropped equipment would hit causing it to do nothing but fall on the floor. I'm a robot repair electrician in a manufacturing facility in East Peoria, IL. I've re-wired my entire house with all my receptacles mounted with the ground lug mounted on the top sides. I've never personally heard of any horror stories of people being electricuted or shocked because of the lug being mounted on the bottom. I just figured if it's a requirement in hospitals, I'll install them the same in my house.

    Source(s): NEC (National Electrical Code) and Hubbell Electrical Manufacturing. If you take a close look at a Hubbell Receptacle, you should notice that when the receptacle is held with the ground lug or hole on the top side, the word Hubbell and any other wording is readable. With the ground hole on the bottom, the wording is upside down.
  • 4 years ago

    The rule of thumb used to be on the bottom, but only for conformity's sake. As of late, many organizations , governments and schools, have specified that the ground prong be at the top. It may soon be introduced into Canadian Electrical Code. Some say that the plug is harder for an infant to remove with the ground on top but I have not experienced any difference. The real reason, and a good one, is that the ground prong is where a child would likely put a foreign object. If the hot and neutral prongs were at the top, then a fork or knitting needle or fingers would more than likely meet with disaster.Note that if the cord is pulled up then the hot would be the first disconnected, with ground up.

  • 1 decade ago

    There is no preference in the National Electrical Code for hospitals or any other structures. It has been standardized to the bottom since 1965 (approx) when grounding receptacles were first used. Either way is approved. Standard receptacles are not meant to be explosion proof as unplugging the cord will create a spark. Hazardous Locations Classified Class 1 Division 1 have specialized receptacles that look nothing like standard household duplex receptacles and have no faceplates. NEMA (National Electric Motor Association)charts are not created by the NEC (National Electrical Code). To the contrary, the NEC handbook which is published as an in depth manual of the NEC, shows almost all the receptacles with the ground down, as is standard.

  • Jim W
    Lv 7
    1 decade ago

    Ground pin up so the possibility of something falling on a partially exposed plug, has a 50/50 chance of not tripping the circuit. The ground pin is longer than the line pins so it will be the last disconnected no matter how it is removed. Look at a hospital, all of those receptacles have the pin up as they should be. The ground down debate has been going on for 35 years or more. Check any NEMA chart and the ground pin is shown up on all receptacles.

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  • Anonymous
    1 decade ago

    In theory it is suppose to be on the bottom. Because if the weight of the cord caused the cord to lets say fall out of the wall plug, it will be grounded to the very last instant. If there was no ground, what would cause the breaker to kick if you should touch the exposed hot prongs? Nothing. So you would continue to get the current thru you non-stop.

  • alvarz
    Lv 6
    1 decade ago

    it really does not matter. But everybody puts the hole down in case we are trying to plug something in ,,,in a dark room

  • Anonymous
    1 decade ago

    I have always done them on top as the same reason Eugene said.

  • 1 decade ago

    If you look around, it seems traditionally, "bottom" wins by majority; (plus it "justs feels" a bit sturdier....) but 'whatever' works! I've even seen them sideways these days, for fitting those space hogging power adapters, etc.

    Yahoo!

    Source(s): not the first, won't be the last!
  • Anonymous
    1 decade ago

    it supposed to be by itself. that said you can have it either way.

    so long as the other two prongs are parallel and next to each other.

  • DIYpro
    Lv 5
    1 decade ago

    It's usually on the bottom but it doesn't really matter.

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