# How to install 3-prong outlets in your old house



## CoconutPete

Recommended tools:










Requied supplies: You might not need as many, but I was doing 20 outlets so I opted for the contractor pack.... I also recomend a worklight if you are doing this at dusk or at night - a 30 foot cord allowed me to run it downstairs where I still had power on.


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## CoconutPete

Unscrew the old outlet cover, remove it and do the same w/ the outlet.










Since everything is metal in my house, connecting the pigtail to the box will provide a ground since the box is grounded through the conduit.


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## CoconutPete

All buttoned up....









Now doesn't that look better?









You should have the same voltage with your pins in the hot/neutral as hot/ground.


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## CoconutPete

I found that on some of my outlets the hot phase was on the left and on some of them it was on the right.

In my houses all the hot wires were black - i'm told it's because they used to use tar on them that they're black but idunno if that's really the case. You might have to wiggle and bend some of the wires but be careful these old wires are insulated with some real brittle stuff. You could install the outlet upside down but I am borderline OCD so I couldn't have any of them going the wrong way :laughing:


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## spark plug

But. Coconutpete; I'm a pre-beginner! I know nothing about installation of the Three-pronged outlets. You only show the pictures of the tools. I have one question; the old outlets have only two wires. Which wire do I connect to the third prong? I heard, there is such a thing as grounding. How do I accomplish that? How am I sure that I don't mix up the wires?


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## Termite

CoconutPete, thanks for taking the time to post your tutorial. I know how much work you went to in order to try to assist others and don't want that to go un-noticed....Not trying to belittle you or your efforts in any way. 

But the thread could be misleading to the layman.

You mentioned conduit. Conduit was/is used in some areas, but the vast majority of residences do not use conduit. Instead, NM wire of varying types is used. In the old days there was no equipment ground wire. More modern homes have it in most cases. In your house, there is an effective path to ground via the conduit back to the main.

In a house without conduit to every single receptacle box, the methods are different. (I'd have to check the code to see if conduit houses are even exempted or if the installation of new receptacles would require the addition of an equipment ground...Not sure)

The NEC code gives a couple options when replacing ungrounded receptacles on 2 wire systems with no equipment ground. One is to pull an equipment ground, which is tough in most cases. *The other option is to install either a GFCI breaker or a GFCI device on the first receptacle of each circuit where you're replacing receptacles, thereby providing protection on all downstream receptacles.* *The code requires that all 3-prong receptacles installed under GFCI protection on ungrounded systems have two stickers on each face plate of each receptacle. One sticker says "no equipment ground" and the other sticker says "GFCI protected".* These stickers come with GFCI receptacles or can be reproduced on tiny Avery labels on a printer if you run out.


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## CoconutPete

Thanks for the additional info Termite. I guess I was missing a bit of info there. This method should indeed only be used in a house where the electrical boxes as well the conduit are made out of metal and provide a nice solid ground.


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## ubergeeken

One thing to always consider in the older houses is that if you upgrade or modify the water supply, ensure grounding continuity is maintained. If copper/metal water pipe is replaced with something non-metal like aqua-PEX, there will be a break in the ground provided by the piping. I could imaging that this would happen if a new water heater is installed with non-copper pipe segments installed at the same time.

If you are not comfortable with accurately determining a successful rewiring by using a two prong volt meter, I suggest a $15 3-prong plug in device that shows lights to indicate any wiring faults - it's a LITTLE more foolproof - green or dark = GOOD, red = BAD (or what ever the device instructions say is "bad")
UPDATE: I just realized that the 3 prong tester is shown in the first picture of the posting that shows all of the tools. Look for the yellow plug in the top center of the photo. This is a VERY handy tool for verifying your wiring.
UG.


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## nap

I really hate to be a party pooper but it looks like the house is wired with BX, like in the old BX where the shield is not acceptable as an EGC. I realize you mentioned this:



> You need a ground, since old houses used metal boxing and conduit, the back of the box itself serves as a perfect connection straight down to the water pipes


.which I really did not understand. If you had EMT all the way to the panel, that is your EGC and all you would need to do is bond to the box with the pigtail (which is what it looks like you did) yet you mention something about going to the water pipe. 

care to expand on that a bit?


Not trying to really beat up on you. It is a nice presentation. Just want to make sure all is well.


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## CoconutPete

ubergeeken said:


> If you are not comfortable with accurately determining a successful rewiring by using a two prong volt meter, I suggest a $15 3-prong plug in device that shows lights to indicate any wiring faults


I didn't have a multimeter and wanted an excuse to buy one :thumbup:





nap said:


> If you had EMT all the way to the panel, that is your EGC and all you would need to do is bond to the box with the pigtail (which is what it looks like you did) yet you mention something about going to the water pipe.


I'm sorry - the bit about the water pipe might be my mistake - could be something I mixed in from another conversation. I was told to connect the pigtail to the box (as you can seein the pics) in order to get the ground - I have not physically traced anything to the water pipes - I should edit the first post.


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## LDSGJA

Thanks for the write up.


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## Jim F

It would be worth it for someone with expertise to post here how best to test if your recepticle box is grounded. I read somewhere that you could touch one probe of your tester to the hot wire and the other to the metal box with the power on and if you have a reading of 120 volts the box is grounded. I don't know if that is accurate or the best way though.


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