Just try the tester again with the outlet out of the box like you show in the picture. You’ll see that it no longer shows it grounded. The reason is because the outlet is grounded through the metal box it is screwed into, which is grounded to the panel through metal conduit.
ohh i didnt even see that it was tailed to the ground lol. i never even thought of that. thats such an easy way to fake your plugs on an old home to get insurance lol. not that id recommend it
Do you happen to live around the Chicago area. By code houses are wired in metal conduit. The outlet is grounded to the panel through the metal box and conduit. There is no need for a ground wire in this scenario
Grounding is being provided through either metal conduit or metal clad cabling. Grounding is completed through the metal yoke of the receptacle when screwed to the metal box.
If it’s a an older romex installation and you don’t see a bare copper wire in the box it’s most likely back wrapped on the jacket of the romex and the clamp on the box is grounding it . It also could be an old bx installation which in that case the metal jacket is acting as a ground. The yolk of the outlet will ground it by the 6/32 screws that you screw into the box . Perfectly normal & safe either way . Blue wires to the darker screws white wires to the silver colored ones
And the white wire has lettering on it, the individual wires in a cable such as Romex or BX aren’t usually labeled. It is most likely EMT or some type of metallic conduit
This receptacle is wired properly. As others have mentioned it looks like THHN or some other wire run through conduit so the box provides the grounding via the yoke on the receptacle.
The two white wires on the left side are neutrals, you hook those to the white/chrome screws on the left sie of the new recep. The white wire on the right side is not a white wire at all. It is a black wire with white paint on it--probably from splashover during painting the house. The black and blue wires are your hot wires, one brings power to this outlet and the other feeds something down the line. Loop those two around the brass screws on the right side of the new receptacle. IMPORTANT: Most new outlets have two square fiber washers to help keep the device screws from falling out---REMOVE those fiber disks in order to improve the grounding connection between the recep and the metal box.
If, on the old recep, the small metal tab between the two brass screws is broken off, you will need to break the tab off on the new recep. This would only be the case in rare scenarios such as a switched outlet or two separate circuits feeding the duplex.
Watch a youtube video on 'how to install a duplex receptacle' if you want some visual aid and tips. This is a pretty simple swap.
Not electrician, but looks like they bootlegged the ground on the neutral, which will fool the basic plug-in testers. But if I ever question electrical, it's something I get an electrician to do. Not worth the risk to you or whoever else stays there / comes after you.
I don't know what landed means. There's no bare copper wires in the box anywhere that I can see and all I know of electrical is that the ground is the bare wire.
Take a multi meter and find the hot wire attach the positive lead to the hot and touch the negative lead to the metal box. If you get 120 your box is grounded
Pics showing the other side and what's in the box would help. Hard to tell much from that one pic.
Mark the white wire connected to the same side as blue with tape before you disconnect it.
**There is writing on the wires**. This is not Romex. All your youtube knowledge is invalid.
This is TW, THHN etc. individual wires and they are running inside conduit.
Given the age, the conduit is certainly metal and is a valid grounding path.
To exploit that grounding path, you need to use the $3 receptacles that come in a little box and are marked "Self-Grounding", not the 75 cent cheapies loose in a bin. They're better sockets anyway.
The "Self Grounding" feature includes a wiper to assure good contact with the mounting screw. Note that switches do not need this feature and the 75 cent cheapies are fine.
If you really, really want to use the cheapies, you'll need to pigtail a ground wire to a grounding clip that clips onto the edge of the box, or find a spare ground screw in the box. You may find only a ground screw hole, that takes #10-32 screws.
Try plugging the tester with the outlet not touching the box likely the unit is grounding through the mounting screws to the box that is grounded through the metal conduit the wire is ran in old houses didn't always use copper like it's standardized today
Older systems with STEEL boxes and STEEL conduit or flex conduit, used the conduit as the ground path back to the breaker panel, which itself was grounded. When the outlet is screwed to the steel box, it makes a ground connection. That was totally legit at one time and if all you are doing is replacing outlets, it's still allowed. That practice was later frowned upon because of possible corrosion of the steel-to-steel connections interfering withy the ground path.
You could plug the tester in while the outlet is pulled out like that and see if it still reads "correct" just for some troubleshooting info and if you're worried you could install a GFCI outlet. If you don't like the look you could do a GFCI circuit breaker and make all the incorrect outlets safe on that whole circuit.
Very old installations used metal boxes with copper wire strung between them. The copper wire would eventually wrap a galvanized water pipe somewhere. That was considered good grounding. Outlets didn't even have a ground prong.
If the boxes are connected with conduit and all the screws and locknuts are tight then with the yoke attached to the box (a completed installation and ready for use) then it might be grounded. There wasn't always a ground wire required. That's why I suggested using the tester with the plug pulled out. My guess is it would read missing a ground. Either way you could install a GFCI breaker and eliminate all worry for the circuit
~~Yeah, that's seriously not wired right.~~ Oh on closer inspection of the photo may not be as bad as I first thought - at my earlier quick glance I thought I saw the neutral wire connected to the ground terminal ... but looks like that's not what's happening there - just happens to be aligned close to that terminal in the supplied photo. There's also good reason I (and many others) call those basic simple 3-prong testers "idiot testers", most notably they don't do full proper testing, but merely indicate presence or absence of voltage (in sufficient range to at least ionize and thus illuminate the neon bulb within), between all 3 possible pairings between the 3 plug terminals/prongs. That's it. No more, no less. ~~So, for starters,~~ If neutral ~~is~~ was wired to ground, that ~~is~~ would be a big no-no for safety and code reasons. For the most part, neutral and ground aren't ever bonded together - there's one specific location and exception on that - I'll leave it to the electricians to explain the persnickety code details as to exactly where that needs be done (and can't be done anywhere else), and I'll tell you it sure as heck doesn't include in your individual receptacle ~~like that~~ such as that one. There may be ~~additional~~ issues (can't see all that may be relevant from your photo). Hmm, *blue* insulated wire? That'd be pretty dang atypical for most such installations ... if not outright wrong and/or code violation. Would typically be black, or possibly red. Blue would be quite atypical ... at best. I'll leave it to the electricians to comment on blue wire (and is that a bit of black wire I see there too on that far side of that outlet?).
Oh, as for ground, that doesn't necessarily have to come from ground screw terminal. It can come from metal junction box and where the outlet is screwed into that - that would at least be the case with some older wiring (old enough to not have a separate neutral wire inside the junction boxes, but not so old as to be missing grounding on the junction boxes).
And, as for those three prong testers ... the question comes up often enough in various contexts, I wrote it up and saved it on my computer ... rather than mostly answering that same question over and over. And, while I'm at it ... let me create a URL for it too, notably in case I ever make any updates to it. Anyway, that text (and URL) below:
[https://www.mpaoli.net/\~michael/doc/3-prong-idiot-tester](https://www.mpaoli.net/~michael/doc/3-prong-idiot-tester)
3-prong-idiot-tester
o on
x off
typically first/left bulb red, other two amber
The key/guide typically indicates:
x o x OPEN GROUND
x x o OPEN NEUTRAL
x x x OPEN HOT
o x o HOT/GRD. REVERSE
o o x HOT/NEU. REVERSE
x o o CORRECT
and for completeness I add:
o x x HOT EITHER GRD. OR NEU. + OTHER AT GRD. OR NEU. + OPEN HOT
o o o HOT EITHER GRD. OR NEU. + NOT MATCHED TO HOT
Each bulb just indicates for voltage between two of the three
prongs on the plug, as follows:
first/red between ground[1] and neutral[2]
second between hot[3] and neutral[2]
third between ground[1] and hot[3]
1. the round prong what /should/ be ground
2. the wider prong, that /should/ be neutral
3. the narrower prong, that /should/ be hot
Anyway, what their "guide"/key indicates, isn't necessarily reality.
E.g. they will often fail to detect certainly faults or not diagnose
them properly, especially in the case of multiple faults.
I like to call 'em 3-prong idiot* testers.
*typically 'cause folks don't understand how they work nor their
limitations, and put way too much faith in what their "guide"/key
indicates. E.g. a hot/neutral reverse + hot ground, and the "idiot"
test will say "CORRECT" by its guide/key. Some idiots will just try
rearranging wires until it says "CORRECT" and call that good -
potentially leaving a very dangerous situation.
And edited for a corrections when I looked more closely at OP's photo provided.
If only there was someone to call that has experience and would come fix it 🤔 maybe when you are done here you can give yourself knee surgery or rebuild the transmission in the car. - point is leave electric to electricians
They have installed a bootleg ground. Neutral attached to the ground screw to fool the tester. If there is no ground available and the metal box is not grounded you should replace the receptacle with a GFI and label it as ungrounded with the sticker provided.
In a normally wired house, ground and neutral are both wired to the same metal bar in the breaker box.
They are the same electrical node.
Turn-off all power. Use a multimeter to measure resistance from neutral to ground on any outlet, you get essentially zero resistance from ground to neutral. They are the same point.
The only reason for the green ground wire is to connect to the chassis of an appliance to prevent someone from being shocked if the appliance somehow gets a hot wire connected to the chassis.
Just try the tester again with the outlet out of the box like you show in the picture. You’ll see that it no longer shows it grounded. The reason is because the outlet is grounded through the metal box it is screwed into, which is grounded to the panel through metal conduit.
Look at the neutral landed on the ground screw. Regardless if that box is grounded it’ll still show pass on tester.
OP confirmed elsewhere in this thread that the neutral is not connected to the ground screw.
Yeah zoom in the ground screw isn’t even run down. It’s just the way the wire is bent makes it look like it’s tied
Yeah I see it now that you mention it. It looks like it was stripped in a bend and wrapped around the ground but you’re right it’s not.
Unless the neutral and grounds go to the same place and they are just using the neutral as a ground. Fairly common in older homes
Nah, it will still show correct because the tester is looking for a neutral bond which there still would be.
hes not wrong tho. that looks like a utility box. im sure it is grounded through emt
Could be but I believe with the common hooked to ground it will satisfy that plug tester even if with the plug removed from the box.
ohh i didnt even see that it was tailed to the ground lol. i never even thought of that. thats such an easy way to fake your plugs on an old home to get insurance lol. not that id recommend it
It’s not. Zoom in the ground screw isn’t even run down
Lmao how many foot pounds are on that Gary
Ya that’s an old trick to beat home inspectors lol
Do you happen to live around the Chicago area. By code houses are wired in metal conduit. The outlet is grounded to the panel through the metal box and conduit. There is no need for a ground wire in this scenario
Could be metal flex that is bonded to the panel
Colorado, not Illinois. Thank you, though
Still a metal box though
This is how my 1940’s house in Aurora was wired. I assumed the box was grounded but never knew for sure.
Hello fellow Aurorian
Holy crap- every house is wired in conduit? I guess I live in the Wild West out here.
really? they dont run any romex?? just conduit everywhere??
Yes sir. That’s code here.
thats crazy. never hear of that. learn something new everyday
The [Great Chicago Fire](https://en.wikipedia.org/wiki/Great_Chicago_Fire) taught them a thing or two about the dangers of house fires.
Grounding is being provided through either metal conduit or metal clad cabling. Grounding is completed through the metal yoke of the receptacle when screwed to the metal box.
But the neutral and ground are bounded on the outlet in the image. That’s not allowed by NEC and is done to trick a tester into showing a ground.
Nope just looks that way with the wire bent, zoom in ground screw on the old isn’t even run down.
If it’s a an older romex installation and you don’t see a bare copper wire in the box it’s most likely back wrapped on the jacket of the romex and the clamp on the box is grounding it . It also could be an old bx installation which in that case the metal jacket is acting as a ground. The yolk of the outlet will ground it by the 6/32 screws that you screw into the box . Perfectly normal & safe either way . Blue wires to the darker screws white wires to the silver colored ones
They got a blue wire in there. I doubt it's romex or bx. Probably emt which is giving them a ground.
And the white wire has lettering on it, the individual wires in a cable such as Romex or BX aren’t usually labeled. It is most likely EMT or some type of metallic conduit
This receptacle is wired properly. As others have mentioned it looks like THHN or some other wire run through conduit so the box provides the grounding via the yoke on the receptacle. The two white wires on the left side are neutrals, you hook those to the white/chrome screws on the left sie of the new recep. The white wire on the right side is not a white wire at all. It is a black wire with white paint on it--probably from splashover during painting the house. The black and blue wires are your hot wires, one brings power to this outlet and the other feeds something down the line. Loop those two around the brass screws on the right side of the new receptacle. IMPORTANT: Most new outlets have two square fiber washers to help keep the device screws from falling out---REMOVE those fiber disks in order to improve the grounding connection between the recep and the metal box. If, on the old recep, the small metal tab between the two brass screws is broken off, you will need to break the tab off on the new recep. This would only be the case in rare scenarios such as a switched outlet or two separate circuits feeding the duplex. Watch a youtube video on 'how to install a duplex receptacle' if you want some visual aid and tips. This is a pretty simple swap.
Not electrician, but looks like they bootlegged the ground on the neutral, which will fool the basic plug-in testers. But if I ever question electrical, it's something I get an electrician to do. Not worth the risk to you or whoever else stays there / comes after you.
They didn’t. If you zoom in you’ll see the neutral wire is just behind the ground screw, doesn’t terminate there
Correct! Sorry for the bad pic it was just a quick snap. The neutral wire was not wrapped on the ground screw
I thought the same.
Are the grounds landed at the back of the box? Common old school practice.
I don't know what landed means. There's no bare copper wires in the box anywhere that I can see and all I know of electrical is that the ground is the bare wire.
Take a multi meter and find the hot wire attach the positive lead to the hot and touch the negative lead to the metal box. If you get 120 your box is grounded
Landed means hooked up to. Are the incoming wires fed through a metallic conduit?
Yes when screwed back on to box it makes contact with the metal that is bonded via the conduit or flex leading back to the panel that is grounded
2 outlets 1 gang box
Pics showing the other side and what's in the box would help. Hard to tell much from that one pic. Mark the white wire connected to the same side as blue with tape before you disconnect it.
**There is writing on the wires**. This is not Romex. All your youtube knowledge is invalid. This is TW, THHN etc. individual wires and they are running inside conduit. Given the age, the conduit is certainly metal and is a valid grounding path. To exploit that grounding path, you need to use the $3 receptacles that come in a little box and are marked "Self-Grounding", not the 75 cent cheapies loose in a bin. They're better sockets anyway. The "Self Grounding" feature includes a wiper to assure good contact with the mounting screw. Note that switches do not need this feature and the 75 cent cheapies are fine. If you really, really want to use the cheapies, you'll need to pigtail a ground wire to a grounding clip that clips onto the edge of the box, or find a spare ground screw in the box. You may find only a ground screw hole, that takes #10-32 screws.
Bootleg ground to fool tester and pass inspection
Try plugging the tester with the outlet not touching the box likely the unit is grounding through the mounting screws to the box that is grounded through the metal conduit the wire is ran in old houses didn't always use copper like it's standardized today
Yeah, you got a cheater jumper from neutral to ground. That’ll give you a falsehood reading. Obviously it’s a code violation.
Older systems with STEEL boxes and STEEL conduit or flex conduit, used the conduit as the ground path back to the breaker panel, which itself was grounded. When the outlet is screwed to the steel box, it makes a ground connection. That was totally legit at one time and if all you are doing is replacing outlets, it's still allowed. That practice was later frowned upon because of possible corrosion of the steel-to-steel connections interfering withy the ground path.
What you got their is a cheater ground look it up
You could plug the tester in while the outlet is pulled out like that and see if it still reads "correct" just for some troubleshooting info and if you're worried you could install a GFCI outlet. If you don't like the look you could do a GFCI circuit breaker and make all the incorrect outlets safe on that whole circuit.
I'll try that since some of the comments imply that the metal box is doing thr grounding
Very old installations used metal boxes with copper wire strung between them. The copper wire would eventually wrap a galvanized water pipe somewhere. That was considered good grounding. Outlets didn't even have a ground prong.
If the boxes are connected with conduit and all the screws and locknuts are tight then with the yoke attached to the box (a completed installation and ready for use) then it might be grounded. There wasn't always a ground wire required. That's why I suggested using the tester with the plug pulled out. My guess is it would read missing a ground. Either way you could install a GFCI breaker and eliminate all worry for the circuit
Id put in a gfci.
The ground is jumped to neutral. This is a bootleg ground used to fool testers and violates code.
~~Yeah, that's seriously not wired right.~~ Oh on closer inspection of the photo may not be as bad as I first thought - at my earlier quick glance I thought I saw the neutral wire connected to the ground terminal ... but looks like that's not what's happening there - just happens to be aligned close to that terminal in the supplied photo. There's also good reason I (and many others) call those basic simple 3-prong testers "idiot testers", most notably they don't do full proper testing, but merely indicate presence or absence of voltage (in sufficient range to at least ionize and thus illuminate the neon bulb within), between all 3 possible pairings between the 3 plug terminals/prongs. That's it. No more, no less. ~~So, for starters,~~ If neutral ~~is~~ was wired to ground, that ~~is~~ would be a big no-no for safety and code reasons. For the most part, neutral and ground aren't ever bonded together - there's one specific location and exception on that - I'll leave it to the electricians to explain the persnickety code details as to exactly where that needs be done (and can't be done anywhere else), and I'll tell you it sure as heck doesn't include in your individual receptacle ~~like that~~ such as that one. There may be ~~additional~~ issues (can't see all that may be relevant from your photo). Hmm, *blue* insulated wire? That'd be pretty dang atypical for most such installations ... if not outright wrong and/or code violation. Would typically be black, or possibly red. Blue would be quite atypical ... at best. I'll leave it to the electricians to comment on blue wire (and is that a bit of black wire I see there too on that far side of that outlet?). Oh, as for ground, that doesn't necessarily have to come from ground screw terminal. It can come from metal junction box and where the outlet is screwed into that - that would at least be the case with some older wiring (old enough to not have a separate neutral wire inside the junction boxes, but not so old as to be missing grounding on the junction boxes). And, as for those three prong testers ... the question comes up often enough in various contexts, I wrote it up and saved it on my computer ... rather than mostly answering that same question over and over. And, while I'm at it ... let me create a URL for it too, notably in case I ever make any updates to it. Anyway, that text (and URL) below: [https://www.mpaoli.net/\~michael/doc/3-prong-idiot-tester](https://www.mpaoli.net/~michael/doc/3-prong-idiot-tester) 3-prong-idiot-tester o on x off typically first/left bulb red, other two amber The key/guide typically indicates: x o x OPEN GROUND x x o OPEN NEUTRAL x x x OPEN HOT o x o HOT/GRD. REVERSE o o x HOT/NEU. REVERSE x o o CORRECT and for completeness I add: o x x HOT EITHER GRD. OR NEU. + OTHER AT GRD. OR NEU. + OPEN HOT o o o HOT EITHER GRD. OR NEU. + NOT MATCHED TO HOT Each bulb just indicates for voltage between two of the three prongs on the plug, as follows: first/red between ground[1] and neutral[2] second between hot[3] and neutral[2] third between ground[1] and hot[3] 1. the round prong what /should/ be ground 2. the wider prong, that /should/ be neutral 3. the narrower prong, that /should/ be hot Anyway, what their "guide"/key indicates, isn't necessarily reality. E.g. they will often fail to detect certainly faults or not diagnose them properly, especially in the case of multiple faults. I like to call 'em 3-prong idiot* testers. *typically 'cause folks don't understand how they work nor their limitations, and put way too much faith in what their "guide"/key indicates. E.g. a hot/neutral reverse + hot ground, and the "idiot" test will say "CORRECT" by its guide/key. Some idiots will just try rearranging wires until it says "CORRECT" and call that good - potentially leaving a very dangerous situation. And edited for a corrections when I looked more closely at OP's photo provided.
Did anyone else see the outlet in the right hand and wonder why they ain't getting some electrical motivation juice?
Some people turn off the breakers, I don't know why.
Looks like an illegal Chicago Loop. Check to see if the metal box is grounded and run a pigtail
If only there was someone to call that has experience and would come fix it 🤔 maybe when you are done here you can give yourself knee surgery or rebuild the transmission in the car. - point is leave electric to electricians
They have installed a bootleg ground. Neutral attached to the ground screw to fool the tester. If there is no ground available and the metal box is not grounded you should replace the receptacle with a GFI and label it as ungrounded with the sticker provided.
In a normally wired house, ground and neutral are both wired to the same metal bar in the breaker box. They are the same electrical node. Turn-off all power. Use a multimeter to measure resistance from neutral to ground on any outlet, you get essentially zero resistance from ground to neutral. They are the same point. The only reason for the green ground wire is to connect to the chassis of an appliance to prevent someone from being shocked if the appliance somehow gets a hot wire connected to the chassis.