I am trying switch an outlet (in Guatemala) from 2 prong to 3 prong. I am not an electrician by trade, but I have read a few books, and have done it a few times at my house in the 'states. But this is a whole 'nother beast.

Coming out of the wall I have two white wires, a black wire, and a bare copper wire. All four go into the 2-prong outlet, I have white and black at the tip, and white and the bare wire on bottom. There are two wires that run in between them.

I am used to the grounding wire being the bare wire. I am also used to just having one positive and negative wire, or live and neutral as is the case with this new outlet (3-prong). I only have one black wire... so I put that in the neutral, the two whites in the live, and the bare in the grounding spot. It tripped the breaker as soon as I turned power back on! I switched the white and black wires, same result. What I am missing here?

If I just can't put in a 3-prong, that is fine.

Not sure if it matters, but both sockets are made by a company called Bticino. I don't know the model of the 2-prong, but the 3-prong is a Domino Avant p1228.

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    Can you get us a photo of the darn thing? Jun 13, 2016 at 4:04
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    First of all with AC there is no "positive" and "negative". Secondly it sounds like the colors are not used in their standard way so I would ignore them. If possible you will want to use a multimeter to figure out what the wires are. Or else you should be able to infer by looking at the way it was wired, assuming it was wired correctly.
    – Hank
    Jun 13, 2016 at 4:18
  • I may not be following everything, but here in the U.S. the black is the hot. It almost sounds like black is the neutral and the other side of the outlet has 2 feeds 1 hot all the time and 1 switched?. This would be my guess. The only real way to know is with a volt meter, or make a tester using a light fixture to check the wires and figure out the hot & neutral wires. It is possible that if the 2 whites are hots and on different legs (do 2 breakers trip when they are together?).
    – Ed Beal
    Jun 13, 2016 at 16:26

1 Answer 1


Guatemala uses the same power standards as the USA. Anyone can do anything, but I'd expect to see US style wiring colors, and not old UK style. In the US:

  • Ground = green or bare (green screw)
  • Neutral = white or gray (silver screw)
  • Hot = any other color (brass screw)

Ever buy a new smart phone and the buttons and headphone jack are in totally different positions? Electrical outlets are like that too, every manufacturer puts the screws in different positions. A common newbie mistake is plugging wires into the new socket based on their position on the old. Nope, you're looking at the wrong thing. Look at the color of the screw terminals.

Now you know how to identify and move wires from an old outlet to a new one.

If you are using the backstab/wire-jab connections, don't, even if the last guy did. If they are backstabs that must be tightened by turning the nearest screw, those are OK.

Looking at wires coming up to the outlet matters too. Look at what else is happening inside the box itself. Also look at how the wires coming into the box are grouped.

Only one green/ground is normal, as all the grounds areenormally spliced together inside the box, with a lone pigtail coming out to the outlet. Two whites but only one black is unusual. Find out what's going on there. It could be that someone is abusing a bare wire as a neutral.

If you want us to help get to the bottom of it, tell us the map of how the wires enter the box, and in what groups, and any splices occurring inside the box.

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