Power Problems

December 8, 2013 2:43 PM

I just moved into a new room in a shared house, only to quickly realize none of the outlets in my room (except for one) is 3-Pronged. Until an electrician comes in to update it, how can I hook up my computer equipment safely?

There is a single 3-prong outlet in the room, in the base of the light socket in my closet. I've been told by the landlady to find a 2 prong power-strip with 3 prong outlets (do those even exist?) or possibly use a Cheater Plug (which I have done before but I'd rather not)

I think my best option is to run an extension cord from the closet outlet and into a power strip. But I'm not sure if that'll over load the outlet since it's a closet light socket. I have my laptop hooked into it now, and it seems fine.

My 2nd best option is to use 2-3 prong Cheater Plug adapter, but that's of dubious safety. I'd rather not.

There's a 3 prong wall outlet over my sink in my bathroom, which i could run an extension chord from, I am obviously not a fan of this plan.

Obviously I'm going to ask her to bring an electrician in to update the room, but she's out of state for a month or more dealing with a family emergency. So whatever solution I find is going to be temporary, but I need my desktop up and running, the sooner the better.

Thanks.

posted by hellojed to Home & Garden (15 answers total)

The point of the cheater plugs is to ground the third prong by screwing it into the screw of the 2 pronged faceplate; unfortunately, these faceplates are often not a good ground.

There's a decent chance even that 3 prong plug isn't actually grounded; someone could easily have replaced the outlet with a 3 prong version without connecting the ground.

It might be worth checking the groundedness even on the supposedly good outlet.
posted by nat at 3:02 PM on December 8, 2013 [1 favorite]

Best answer: It is common for the metal box behind the outlet to be grounded, and for the receptacle to expose that ground via the center screw. If so, a cheater plug is perfectly safe. Here's how to find out if this is the case:

Disclaimer: Be VERY CAREFUL. It's difficult, but not impossible, to hurt yourself with these directions. The golden rule: Make sure that there's no pure-metal path from one hole to the other. In other words, don't touch the probes to each other.

Get one of these:

110/220V voltage tester

If you've never done anything like this before, it will be a bit unnerving to jam something other than a normal plug into an outlet. You might want to try it once or twice with the power off (or even just on an unplugged power strip) to get the hang of it.

First off, make sure your tester works by putting one probe into the left side slot and one into the right side. The "110" light will light up. Once you've confirmed it works, pull the probe out of the longer slot (if one is longer; if they're not, then you have *very* old wiring and these directions are probably invalid.) and touch it to the screw in the center of the outlet plate. You may have to scratch it a bit to get through paint, make sure you're touching metal. You can also safely unscrew the screw and put the probe into the hole, touching the metal screw threads.

If the "110" lights up, you have a grounded outlet. You can safely use a cheater plug. Just unscrew the screw, put in the cheater plug, and screw it all back together.

You can test your new grounded outlet with one of these if you want to confirm that it's now wired as it should be.
posted by Hatashran at 3:04 PM on December 8, 2013 [3 favorites]

Also, as a more advanced solution, if the box is grounded, you can safely replace the existing receptacle with one of these to have a genuine grounded outlet.

But that is a more advanced fix than simply using a cheater plug.
posted by Hatashran at 3:07 PM on December 8, 2013

Response by poster: Hatashran: I have a multimeter lying around that I've never used, could I use that to test the outlet instead?
posted by hellojed at 3:10 PM on December 8, 2013

hellojed: Yes you could - set it to VAC mode and look for either 120VAC or zero.

The American power system is somewhat inconsistent in what it calls the 120V standard residential voltage, often referring to it as 110.

Also, I didn't realize that the outlet in the closet is on a light fixture. I'd bet that it's not grounded either, despite the existence of a third hole. You can test for grounding there by looking for 120VAC between the smaller hole and the ground hole.
posted by Hatashran at 3:14 PM on December 8, 2013

Response by poster: Thanks for the tip Hatsharan, I tested all my outlets and it looks like none of them are grounded, even the closet one.
posted by hellojed at 3:27 PM on December 8, 2013

In that case, you can replace the two-prong receptacle with a three-prong Ground-fault receptacle (The kind with trip and reset buttons on them, like you find in bathrooms). It's not ideal, but it is up to code. You have to put a "NO EQUIPMENT GROUND" label on it, but it will provide protection similar to what a grounded outlet would provide.

There's lots of information on the Internet about it, most of it inconsistent. Good luck.
posted by Hatashran at 3:47 PM on December 8, 2013

As a double check, set your multimeter to ohms (which may involve changing one wire probe as well as the dial) then place one probe in the round ground outlet and the other probe on the screw in the middle of the outlet faceplate. If it reads zero, then your outlet should be grounded.
posted by weapons-grade pandemonium at 3:49 PM on December 8, 2013

I was going to say that if it's just going to be a few days until the electrician comes, I'd just put in cheater plugs, not even bother with the ground prongs, and just unplug things whenever I wasn't in the room to keep an eye on them. However on closer reading I see it will be over a month. In that case I'd check to see if my outlet boxes are grounded with that multimeter you say you have lying around, and if they were then I'd install cheater plugs and I would hook up the ground prongs. If they weren't then I'd install a few of those ground-fault plugs that Hatashran mentioned, for running any of my gear that I thought might stand a chance of zapping me or causing a fire should something go wrong with it.

Also I'd email my landlady and see if she'll agree to let you bring an electrician in at your cost and then pay you back when she returns. Well, depending on how much I trusted my landlady.
posted by Scientist at 4:37 PM on December 8, 2013

Just be prepared - depending on the vintage of the house, CORRECTLY installing a true grounded outlet may be more expense than the landlord is willing to commit to, as it may involve running new wiring to the outlet, and/or installing a ground bus bar in the fuse/breaker box, and/or actually running an appropriately-rated ground line from the fuse/breaker box to the ground outside. As Hatashran says, the by-code, but relatively cheap way to do it is to replace the outlet with a GFCI, but make sure if you do that that you don't assume the outlets down-the-line are also safe to just install a regular 3-pronged plug in - you need to install a GFCI in -each- outlet for that to be kosher.

Were it me, and I was in a city location with fairly stable power, and it was just computer equipment, I'd probably just use a cheater plug. The primary risk is to the power supply and/or motherboard, and not to you. If I was in an area with more questionable power, I'd swap out a couple outlets with GFCIs and use those.
posted by jferg at 6:38 PM on December 8, 2013

Oh, forgot to mention - the ungrounded GFCI will not do much to protect your electronics, if that is your key concern. It will serve the purpose of protecting -you- from potentially being the path to ground in the event of a short.
posted by jferg at 6:44 PM on December 8, 2013

For your safety, GFCI without earth connection is sufficient. The danger is an internal short from hot to the metal case of your desktop, then from the metal case through you to something else. GFCI will protect against this scenario. You do not need a real earth connection for any other reason (for example, the xbox uses 2-pin power cords; it is just as safe and surge-resistant as grounded PC power supplies; it can lack an earth because it is doubly-insulated and meets isolation specifications).

Don't bother wiring in an outlet; buy an extension strip or adapter with GFCI + a cheater and you are good to go, and you can keep it for future rentals as well. Also about the same price as GFCI outlets anyway.

I have worked on many old houses; it is extremely unlikely the electrical outlet is located in a metal box that is earthed, nor can I see a landlady paying to install grounds when it's fine for everyone else and can be fixed for $15 from home supply store.
posted by flimflam at 1:07 AM on December 9, 2013

I just moved out of a house I'd lived in for 13 years. It only had 2-pronged plugs, and I used the adapters.

The house is still standing and my computing equipment still works.

Not saying it's the safest setup, but it didn't pose a problem for me.
posted by mudpuppie at 3:31 PM on December 9, 2013

As a double check, set your multimeter to ohms (which may involve changing one wire probe as well as the dial) then place one probe in the round ground outlet and the other probe on the screw in the middle of the outlet faceplate. If it reads zero, then your outlet should be grounded.


Please do NOT follow this advice. The outlet itself provides an internal connection between the center screw and the grounding contact opening. This test will show continuity, but provides absolutely no information about whether or not the outlet is properly grounded.
posted by doctord at 4:15 PM on December 9, 2013

Response by poster: As a followup, I've been using a cheater plug with an GFCI surge protector, so far I have not had any issues, and it should work for another month until my landlady gets back.
posted by hellojed at 11:49 AM on January 10, 2014