How to Understand Two-Prong Outlets | Ask This Old House

[Music] okay heath a question we get all of the time people frustrated with their two-prong outlets because they've got a three-pronged cord exactly right so what do we do about it so the first thing i want to start is by defining what we have here so this really well is an outlet this again yeah we're going to go through this again so an outlet is really defined as a point in the system the wiring system where current is taken out and supplied to equipment so it could be more than just this receptacle outlet is an outlet but there's also appliance outlets there are lighting outlets there are smoke detector outlets so the outlet's the point where the current's taken out and utilized so technically you want to call this a receptacle outlet okay because the device is the receptacle so you're installing the receptacle into the outlet making it a receptacle outlet gotcha either way we are left with the problem right some of the older homes have two prongs in the receptacle and most of our modern appliances have three products yeah a lot of surge strips those kind of things are going to want a three prong to plug in so what's going on here why two and when did we go to three so two you're going to see in older homes older wiring systems where you're going to have two conductors you're going to have typically the black the hot and the white what we'll call the neutral that are in there so we only have those two wires to complete the path for everything being utilized which is why you have the two prongs what we see out front is really telling us what's out there what should be what's inside yeah gotcha and these days instead of just two conductors we add a third so now we add the grounding conductor right and that's where we'd have this lower prong here and you can plug that three prong cord in you've told us a million times grounding is essential remind us why it's so important safety so you're hoping current never ends up on that grounding wire you don't ever want to have to utilize but if you do need it you want it there it provides a low resistance path for a current ground fault current specifically to get out of uh out of the way hopefully induce the overcomer protection device to trip whether it's a breaker or a fuse by letting too much current in and provide a level of safety give me an example where this two conductor wire could end up having current come out of this conductor and into the whatever it's attached sure so especially when you see something like this in a home you know the wiring is probably older it may be a little brittle it may be time for inspection and have some issues a picture of washing machine that older washing machine plugged in a basement and a two-prong receptacle if that's plugged in and that black wire happened to wear down over time rubbed through and is now touching the metal housing that metal housing is now energized but because it's not grounded it doesn't know it can't has no way to get the current back out of there so it's sitting there energized someone can simply walk up literally that washing machine is now electric exactly so you could walk up touch the water pipe hit the machine and you're the path of least resistance now you're going to get shocked and it becomes a real safety issue in the alternative situation if it had been plugged into a three-prong receptacle yes that means and we actually had the proper grounding conductor inside of there you wouldn't be the path anymore that is the path of least resistance if everything is done correctly current comes in shorts out there goes right out trips the device so that begs the question if i have a two-prong receptacle which suggests i have the older wiring behind it right is this a safety risk and do i have to get rid of it we don't want you to panic about it but when you see them you typically realize that the home is probably older the wiring is older so you at least want to have it inspected make sure the device is in good shape like this one isn't cracked isn't broken isn't over utilized turn the circuit off check the wiring make sure the insulation hasn't broken down that it's not brittle that it's it's not showing any signs of excessive wear if it's in good condition can i continue to use it if it's in good condition yeah i would say it's pretty much safe to you know keep using that but you do want to look at upgrading that down the road and how do we upgrade well ideally you'd like to start upgrading the wiring as you make repairs as you renovate rooms literally get rid of the wires behind the wall replace it with this exactly start installing that that's a big lift it's not within everyone's budget and it's not always possible but there is a solution if you want to put that three-prong device in there so you can use some of those things and that is you can install this and this would actually satisfy all the modern code issues that we have with replacing a receptacle and trying to make it a three prong even though we only have two wires back there so i'm familiar with this i got a bunch of them in my bathrooms in the kitchen three prong it's got the test reset so this is gfci protected it is but it's also afci protected arc fault yes so when you replace your receptacle you also have to arc fault protected as well so this device does both it does the gfci and the afci and it lets you take that two prong out install the three prong without having the grounding conductor wait a second wait a second this one is set up to receive all three conductors hot neutral and ground you're telling me that i can put this in there when there's only a neutral and a hobby can yes that's an acceptable replacement because it provides two other levels of protection oh it's providing you with the gfci protection and the afci protection all in this device oh that single device so it's kind of a workaround it is but you're protected you're protected you're adding a great level of safety and it lets you get to where you need to be which is using your modern day cords to put it into the receptacle right dagnag that's actually pretty clever yeah when you install these you just want to make sure you label everything properly and it'll come with instructions and the labels telling you where to apply them and how to apply them both gfci and afci all right well i mean it is good to know that you can upgrade your outlet to upgrade your receptacle to something that provides the safety and the peace of mind it's nice that there's an option that you don't have to rewire the entire room to go ahead and get a little bit of this beautiful awesome great advice thank you all right thanks for watching this whole house has got a video for just about every home improvement project so be sure to check out the others and if you like what you see click on the subscribe button make sure that you get our newest videos right in your feed

Channel: This Old House

Views: 152,146

Keywords: This Old House, DIY, Construction, Home Improvement, Ask This Old House, Building, electrical, Heath Eastman, Kevin O'Connor

Id: 3-zmU6upbUo

Length: 6min 2sec (362 seconds)

Published: Wed Oct 06 2021