The Dangers of Shared Neutrals: How To Avoid Being Shocked

[@davidwoodard1820]

Great video! Your statement that will stick with me from this day forward is "Electricity doesn't care about the color of wires".

[@bernsfindsandmore7636]

Works for me as well... if only life was this way as well...

[@johnsaake2303]

one thing I was taught when taking apart joints is to break the hots, neutrals, then the grounds; and the opposite order when putting joints together. That and keep your boots on the ground and your idle hands off of metal boxes cans or cabinets. Both are good habits to form alongside not working energized whenever possible

[@lglubbock7593]

boots on ground?

[@mackellyman5642]

One of the best comments.

[@drband8181]

Great explanation. I came searching for why I got a shock from a neutral when the breaker for the circuit was off while installing a LED power supply in place of a light fixture. It was a shared neutral situation I found out here! Something new to watch for. Thanks for the info!

[@binkleyt]

Love that whiteboard addition to the videos -- super helpful to see things visualized like that with the fast changes (less clunky than a real whiteboard..writing, erasing, etc...)

[@tochia]

🤔🤔🤔🤔

[@ClutchTFS]

They're called smartboards I had them in elementary and highschool pretty sweet!

[@sotjonbixho3272]

😮😮😮

[@raymondsciara]

Awesome video. I want to take this opportunitty to say thank you Dustin for this great content in your channel. I passed my Journeyman test in August 2023. I would not have done it without your videos and all the help I got along the way from knowledgeable electricians that went out of their way to make sure I understood theory and field practices. I want to learn more stuff. I am currently working at an industrial work area. I am still a bit intimidated by the environment, but the experience I am gaining keeps me motivated. I have learned that failure is apart of the learning experience. I will never let past and future failures keep me from trying my best as an electrician.

[@HaffDeadFred]

Great thing for me to learn about ,we just did a panel upgrade for a customer and the inspector wanted me to “handle tie” all ckt breakers that share a neutral and zip tie the neutral wires together to ID them

[@alphasaiyan5760]

Exactly. Breaker handle ties 👍

[@trebochet]

Yes Multi wire branch circuits , and don't zip tie them. Tape them at the panel all together with an identifying tape color if you have several similar circuits , make your inspector happy 😊

[@jasonirion6664]

You can melt that neutral wire like a candle if both positive wires are landed on the same phase. If they are loaded up double the amount of current is returning back on that neutral. The breakers won’t trip but that neutral will fail spectacularly. Maybe a video should be done on this because it is easy to make this mistake. Keep up the great work !!

[@docferringer]

He's got that nice "teaching wall" that has demo outlets and panels, so he could use that. I say New Years is a great time to light that firecracker!

[@lloydmills9619]

Positives huh.

[@freddybee4029]

@jasoniron6664, I think you need to stop watching youtube video’s, and go to a proper schooling, to learn the difference between ALTERNATING & DIRECT CURRENT applications.

[@GreasyReecey]

Hot, not positive. Also, it's actually difficult to make that mistake because a 2 pole breaker connects to adjacent bus bar tabs that alternate phases. So unless you go against code and use 2 separate nonlinked breakers and install them with a gap in between them or an odd number gap in between them and land on the same phase, this problem wouldn't happen.

[@mikejohnston179]

​@@GreasyReecey Enter home owner re-arranging the breakers in the panel, so they are in a more logical order. "Why are these two kitchen breakers linked together? That's dumb. I think the breaker for the microwave belongs between these two."

[@danhardhat2]

Single pole breakers are allowed on exterior lighting circuits with a shared neutral [NEC 225.7(B)]. NEC recognizes the voltage drop benefits of sharing the neutral because typically long distances are involved with exterior lighting and they recognize the liability of loosing multiple exterior lighting circuits from a single short if multipole breakers were required. So, extra heads up when working on parking lots and street lighting.

[@barryomahony4983]

225.7(B) doesn't say anything about breakers, but it does call the multiple ungrounded conductors a "circuit" (singular), as in a multiwire branch circuit. 225.7(A) says outdoor lighting circuits shall comply with 210; including the handle tie requirement for MWBCs. Something of a moot point now since 226.7 has been deleted in the 2023 NEC; it was an unnecessary section IMO. But yes an extra heads up when working in those locations; a common danger is the lack of EGC.

[@danhardhat2]

@@barryomahony4983 You're right...2023 NEC has deleted the exception that permitted the shared neutral for exterior lighting. There are many municipal lighting systems that use the shared neutral...It allows street lights and the seasonal lighting receptacles on the poles to run at 120V, and have each pole stagger circuits so if there is a fault, only half the lights would go out, which is much less dangerous for drivers and pedestrians. Now without the shared neutral, the conductors will go from #6's to #2's and have to run an extra neutral. And there will be current on all the neutrals, wasting energy (about 1.5% wasted energy - not much but still less efficient). I disagree with the NFPA - there are many good reasons for that exception for exterior lighting in the code.

[@alhawkins3376]

Its not just exterior lighting but where you have sensitive equip. like a lab, just removing the neutral could fry whats on those circuits, even cutting circuits off not together can also do it.

[@professorg8383]

@@danhardhat2 Well, I'll have to reread this but I didn't think it prohibited these shared neutral circuits. These are completely safe circuits and quite useful and practical for long runs. Not very common in regular residential wiring. These used to be quite common in long agricultural buildings and shops. As you point out, there are applications of this that make a lot of sense. I tend to look at it this way, what properly trained electricians would think it OK to spilt a two pole breaker into single pole circuits??? I can kinda see a DIY homeowner not understanding, but then I have long advised against electrical work as a DIY skill. I blame the internet for convincing people that they know what they are doing, when they clearly don't. What makes it even worse is all the stuff posted from 240 volt countries like "this is how it works everywhere in the world"!!!! It just confuses the hell out of DIYers. wh really should not be doing this work in the first place!! Does anyone in their right mind consider DIY surgery?? IDK, but I'm guessing that most people realize that the consequences of not completely understanding or doing something wrong, might be fatal. But working on electrical without fully knowing what you are doing, can have the same kind of fatal consequences.

[@jameshunt5316]

⁠@@professorg8383not trying to be that guy but most farmers do DIY surgery on their livestock since the cost to have the surgery done at the veterinary clinic is often close to what the animal is worth. Either way you are going to lose the animal, might as well give it a shot. I assume it’s the same for people who want electricity in low income areas. Many countries make it nearly impossible to live without electricity anymore so I assume it’s out of desperation. Most people would prefer to call an electrician or a surgeon for everything but many people can’t afford either.

[@kkalafus]

The most basic question that I wish the video spoke to is, how do you know if there's a shared neutral? Inside my panel I saw red wires used for 120 v circuits. That caused me to trace where the wire was going, which was Romex that also had a black conductor from another circuit. I hadn't seen this before and ended up learning more about it on your channel. IMO it's crazy that shared neutral circuits are allowed in residential construction because over the life of a home, someone can easily rearrange things in the panel in a way that's unsafe. In one of my circuits, someone had put the red and black wires on the same phase and ended up with double current on the neutral, which was a fire hazard and had to be fixed. Our home inspection missed this issue.

[@danielherman9483]

Not an electrician, so take this answer with a grain of salt, but the only way to somewhat know for sure is to open the panel and trace the wire for the circuit that you're working on to see if it's something like a 14/3 or 12/3 (and then double check that they're on different phases like they should be). Even then, you have no guarantees that someone didn't do something insane like tie neutrals together from different circuits if there are multiple circuits in a junction box. If you didn't wire it yourself (meaning you're not 100% positive how everything is wired), just take the 30 seconds to put your meter on each wire to see if there's voltage. Btw just because the wire is red doesn't necessarily mean anything at all - 14/2/2 or 12/2/2 is a thing, so a single piece of romex could have enough conductors in it for 2 full circuits with no shared neutrals, but there may still be a red wire present there.

[@JPLaJeunesse]

Usually 2/2 wires they indicate with a red mark on the neutral with the red and black mark on the neutral with black

[@weavercattleco]

I've got a degree in electrical engineering so maybe I can help. You won't know! Also, it's not going to be an issue unless you mess with the point where the neutrals are tied together or in the circuit breaker panel if the other breaker is still on! Best advice from someone who have 30 years experience, just turn the entire circuit breaker panel off if your not sure about how things are wired. You could also use a tone generator to see if the neutrals are shared. Fluke Pro Probe 3000 toner, there are videos on KZbin how to use this tool 😉

[@krakenwoodfloorservicemcma5975]

Home inspectors aren’t usually electrical professionals. It’s not their job to get in to the nitty gritty of the panel.

[@jimlangley840]

I know of a journeyman that became the neutral on a 277 volt lighting circuit, it knocked him off a 12 ft. ladder and fried his brain.

[@csimet]

Great explanation, as usual! I ran a new 2-pole 20A breaker with 12/3 dedicated line for my shop table saw, splitting the duplex 5-20R receptacle into 2x 120V 20A with the shared neutral. It is so I can upgrade it down the road to a 220V 20A simplex 6-20R receptacle when I upgrade my table saw from 120V to 220V. In the mean time, it provides the saw's 120V and an extra outlet for some lights until then. The key thing is it all ties back to that 2-pole breaker so both "legs" are shut off and never just the one. Hopefully this meets code... chime in if not please!

[@web1ece]

I'm planning on doing this in my shop as well... I'm not sure why if it was on a double pole breaker that it would be a problem

[@perryallan3524]

Great explanation... I'm a homeowner who was taught by an electrician in my youth on how to wire houses and all kinds of electrical safety items - and went on to become an Engineer; but still do most of my own wiring. Unfortunately I live in a 70 year old house (just a few years older than I am). While I have rewired the basement the plaster walls in the living areas are too nice to open up the walls and redo it. In my past I have dealt with 2 houses with nob and tube wiring among family members.... Assume everything is live unless a test to ground confirms otherwise (and you might have to run a cable to a bathroom or the basement to have a good ground). I rewired both of those houses starting with having an electrician install a new breaker panels and me doing all the work past that (and yes there were building permits and I was inspected multiple times). Interesting story is that in one city the electrical inspector came in to inspect my brothers new large 2 car garage wiring which I had done for my brother. The inspector recognized me and said he was glad to see me as my work was always 1st class. In this case my brothers old original very solidly built 1 car garage had been moved a 100 ft or so down the alley to ladies lot who did not have a garage and there was only room on her property for a 1 car garage (reused the old garage). So this lady was really happy to get a garage for just he cost of a cement slab and anchoring my brothers old garage to the slab. During the wiring inspection of my brothers new garage this lady came over and talked to the inspector about her desire to get her garage wired but could not afford the prices the electricians quoted; and did the inspector have any advice or options. The inspector asked her if she knew me to which she replied "of course - he's been helping his brother on his house with a lot of things." The inspector then told her that if she could convince me to do the work that he would approve it. Technically, he should not have done that. In my State a person can do their own wiring as long as proper permits and inspection is done. A person can assist an immediate family member as well. But my understanding in my State is that's where it legally ends. I thought it was a nice complement. She was happy even though she had to dig and fill in the trench for the underground service to her new garage.

[@phildegruy9295]

Super good video. It is good to instruct the helpers/apprentices to be very careful in old houses and make it a requirement to turn everything off at the main before working on any circuit where the neutrals will be broken apart. One for safety and two to keep from blowing random things in the house up from open neutrals. Bought an older house and discovered that every single 120v circuit in the house were ran in a loop of conduit (from and back to panel) with a junction box every 10'. The circuits had 4 neutrals total from the panel and every neutral was half ass twisted together as no wirenut would fit with a piece of tape for cover at every junction box. Honestly don't know why the house had not burned down.

[@traog]

In cases of a shared neutral it should be connected to a load with a pigtail so that if the load is to be disconnected the neutral connection isn't being opened. Some of the older buildings I work in have 120/208 3ph panels with 3phases sharing the same neutral, I see it all the time non pigtailed neutrals at receptials and lighting ccts it can be a challenge to determine which 3 ccts are involved.

[@thebluebellschoolofdance932]

First off, thanks dustin for making these videos. Extremely helpful. In addition to what you explained, it should be noted that a multi branch circuit(shared neutral) should be on separate phases. Never coming from the same phase! Keep on spreading the good word my fellow sparky.

[@kls2020]

When you're dealing with wiring of questionable installation quality something I started doing was to use a clamp on current ammeter or current probe whenever I came across commoned up neutral wires (such as multiple white wires in a wire nut) to solve the mystery . Before removing the wire nut and separating these mystery neutrals check each wire with the clamp on ammeter for presence or absence of current . If there is different current reads on each neutral wire you can compare the load current going out from each breaker and when you have a match mark the neutral wire with that breaker number then turn off the load breaker and verify both line and neutral reads go to zero amps . If two circuits both read the same current value add more load to one circuit to make them easy to distinguish between the two circuits.

[@christobaldaetz6062]

Back when I first started as an electrician, we ran a 12/3 for two circuits. But in the panel, we installed a two pole breaker. So that when you had to work on that circuit, you could do it safely. Now they make 12/2/2 makes it easier to deal with.

[@elcabronsontres]

I know this is late brother but I know of a fellow electrician that past because of this very situation. South east texas last year. Please be careful out there brothers.

[@tomhoser9325]

Excellent explanation of the shared neutral. As a lighting designer, we could share a neutral with each of three phases when laying out a large system like an office corridor. It was easy to balance the loads, they were all the same fixtures with the same lamps, and it did save a ton of wire in these big spaces.

[@KameraShy]

Glad to see this issue is being addressed. I am in a 30's house where wiring is all in conduit. Everywhere they could, shared neutrals were used. When I added some circuits years ago, I just assumed this was standard practice, followed it and did not fix them. But somehow it just did not feel right. This was long before the days of the internet, KZbin and all the learning resources now available. I did go back and check the circuits. I actually made and kept detailed diagrams of the wiring because of how they mushed so many wires together in a single conduit run. They all seem to be on different phases. If I ever need to do more, I will run separate neutrals.

[@zlcoolboy]

I guess at least there was conduit. it was probably considered to be an excellent installation when it was done lol.

[@alexknight7191]

I'm assuming it's BX flexible conduit. My and my parents' house (in different cities but both in the northeast) are from the '20s and both have that. Agree if everything is on opposing phases it should be totally fine from a load perspective, but that old BX should be replaced eventually.

[@FeguerFineArt]

Love your videos! I have been a draftsman (drawing) all my life, not by profession, but a drive. I love drawing day. I always work stuff out by drawing. The way you explain things and visually show it is Awsome. I have had so many AH.HA moments this way. Thank you so much, keep rocking it! God Bless.

[@Ephesians-ts8ze]

I went to work for the state (TX) recently and it’s pretty common for the electrical contractors to share neutrals on new installations. I’m a maintenance electrician and I’m getting pretty frustrated with the crap they leave behind for us to deal with. There’s shared neutrals everywhere and an “anything goes” color code. In Austin it’s red, black, blue for low voltage and brown, yellow, purple for high voltage. But within Austin’s jurisdiction State jobs are not subject to AHJ. So some contractors do it by Austin code and others do it by everywhere else color code.

[@workingshlub8861]

up here in new england i see this all the time with older homes....nothing is ever labeled in the panel of course..

[@dracula3811]

The shared neutrals on new installations being allowed is on the inspector for passing it. It isn't code.

[@barryomahony4983]

3:26 You could still get a mild shock from the upper white conductor if you touch it while grounded; a small portion of the return current will flow through you.

[@tnspnk3]

Good point. But I'd say "could" not "will." While many things are fairly straight-forward, this would be complicated. Depends on a lot of factors, like how "grounded" are you and possibly where you are along the circuit path. Not to minimize the danger; I sure as hell wouldn't touch it.

[@HoosierRallyMaster]

Absolutely! If your body is providing the path to ground, then that "stub" white will all-of-a-sudden have current in it.

[@AaronSchmid1]

We installed multi-wire branch circuits on the west coast well into the 2000's. Once arc faults started being required in more areas is when we moved away from it. So expect to see it in houses up to 2008+.

[@drewwassel3367]

One potential way you can get shocked from a neutral is if the breaker is off but there is a device with a large capacitor connected then it could energize the circuit

[@tnspnk3]

Lol. I shouldn't laugh, but somehow it just seems funny. Capacitor's 101: Q: How to discharge when the neutral is cut. A: Insert random electrician for path to ground. :)

[@cwalton56]

40 years ago, the Contractor I worked for used lots of Edison circuits in new homes we wired. Another electrician I worked with told me of this very situation where he got shocked touching a neutral wire.

[@TCAPChrisHandsome]

I'm not an electrician, but I have done some electrical work, because my state is pretty lenient with that stuff. However, my rule when I fool with anything electrical is to shut off as far back as I can without it being a problem. For example, I had to change my dryer plug awhile back, I flipped the breaker labeled "dryer" and I tested the plug, and it still said 120 volts. Someone had something wired wrong, and I didn't know where the other line for the dryer was, and I still don't know what the second line on the dryer breaker went to, so I just had to kill the whole house, just to change one receptacle. That's the fun of living in a 30 year old house trailer, that God knows who has lived in before you.

[@GreenEarth140]

You did the right procedure by shutting the entire home down UNTIL you can locate exactly where "someone wired something wrong". Always , ALWAYS METER EVERYTHING YOU ARE GOING TO WORK ON BEFORE YOU TOUCH ANY PART OF THE CIRCUIT !!!!! YOUR LIFE MAY DEPEND ON IT !!!!!

[@didriksoderstrom9891]

Working on an old house with shared neutrals (and buried boxes) right now and it’s driving me bonkers. Thank you for the reminder to make sure I’m being safe with this stuff. Old greenfield cable is always waiting to bite you at every turn.

[@Bobcat1950]

Several years ago I built a post and beam garage. I intended on doing a little woodworking and other projects. I was very busy and couldn’t find the time to wire it myself. I hired a seasoned electrician with a great reputation. I had already set the sub panel and pulled the cables. I explained that I wanted 3/4” conduit with metal boxes and GFCI receptacle on each circuit. I came home and found that he used 1/2” conduit and shared the commons and grounds and had not installed the GFCIs. I called him and he said, “The GFCIs were not necessary and that he was able to pull all the wires through the 1/2” conduit. I paid him and a few weeks later installed the GFCIs which wouldn’t work. After asking an electrical engineer, I found out that a GFCI meters between the neutral and the hot wires not the hot and ground. They shouldn’t be wired using a shared neutral.

[@Goldern]

GFCI calculates the energy going in (hot) and going out (neutral), if the difference between hot and neutral is big (someone turned into Earth and got zapped) then it will automatically trip itself preventing further damage. It does not care at all if Neutral is shared or not, but bear in mind that after Neutral and Hot exits the GFCI, you can’t connect equipments before the GFCI Neutral and after GFCI Hot or there will be imbalance and it will trip. The simple fix is to put a neutral bar connector after/before the GFCI, that way if you need to put an outside circuit that won’t be affected by the GFCI (like a light circuit, to easily find the GFCI after it trips and then reset it), then you’ll be able to wire the light breaker before the GFCI and finish it with the Neutral before the GFCI.

[@GS-lh2nx]

Aka multi wire branch circuit? I have some of these in my 70's home. It really threw me off as to why I had 240v circuits feeding 120 volt devices until a friend explained it to me. Excellent video as always. Thx

[@danukepaintball]

Those "You can't be shocked by a neutral" people aren't going to like this one either LOL

[@thewiseguy390]

Open group and loose neutral hurt more than the hot lol

[@dougfoster445]

@@thewiseguy390 why

[@Vinka236]

@@thewiseguy390 I can confirm this and it does hurt like hell.

[@Sandman206]

Confirmed..it hurt.

[@kyle3694]

Only a dummy is a the reason for someone being shocked by a neutral wire bc a neutral being wired improperly would cause that to happen. Which would be due to a dummy improperly wiring the neutral. A properly wired neutral cannot shock you.

[@patrickgr1547]

Thank you 👌 my 1940’s bungalow I keep finding tricky electrical issues with. Spilts tapped up in the walls and in the attic entirely without junction boxes. Then when the time came and the old fuse panel was replaced with circuit breakers. They threw some new wires at it and walked away. I’m stripping the attic out to air seal and insulate. I’m installing new low voltage LED lighting while I’m up there.

[@michaelm4865]

Adding to your example @ 4:50, by connecting the neutrals of the loads you basically create a series circuit, increasing not only voltage but resistance. Most likely damaging the load.

[@justaresiguy6197]

I always wondered why, when doing panel swaps, we had to put three wire homeruns on a 2P breaker… that makes a lot of sense now!! Thanks man!

[@daveinvictoriavirginia7959]

This is why you never stop looking for unknowns. Just cause it hasn't happened to you, doesn't mean it won't. Thanks for your lessons.

[@johnt2491]

I'm not an electrician by trade. Yet watching this video made my jaw drop. 😮😮😮 WOW (and scary). Fantastic information, thank you so much!!!!

[@samuelg3586]

Awesome video. I am an HVAC Service tech by trade and trying to learn more about non HVAC electrical so this is very helpful

[@robburton3255]

Wish I had seen this sooner! I was baffled when I got a good buzz! And then I couldn’t figure out why I would see 240v. Thank you for clearing that up! The house was built in 1967. Some crazy wiring in it.

[@danielsharples7649]

Im an electrician from Australia. Just moved to Canada and been seing alot of weird shit like this. We don’t have split phase in Australia. Thanks so much for this explanation.

[@JPLaJeunesse]

I appreciate this video so much, with how we do wiring currently most apprentices never learn how or why this was done. In my area there was a housing boom when the wiring was like this and I encounter it frequently and use the opportunity to teach it but now we have a great illustrated video!

[@totallyawesome80s55]

When I first started, we were still allowed to run three circuits (3-phase) on one neutral, and it made pulling wire a lot easier. And as long as the shared neutral was indicated, it was perfectly safe.

[@network_king]

Other danger i see is if on and remove the main neutral then you have 240V like you said but also may end up with the loads being wired in series. Series in theory each would get 120V but it would depend on the current draw of those devices. The larger draw would pull more voltage but could also fry the other device due to drawing too much current through it. This is also why when I work on even dead circuits I splice things in this order Ground, neutral, hot. That way you are really only exposing yourself to the hot potential once as oposed to splice the hot then the neutral. Ground first just should there be issue and sometimes for small fixtures it is a nice anchor point to hold it till you can get the other wires linked.

[@TomCee53]

Your basic logic is sound, but I think you’re confusing voltage and current. The larger draw would get less voltage. If you run a 60 watt bulb and a 100 watt bulb in series across 240 volts, the 60 watt bulb will see 150 volts and the 100 watt bulb will see 90 volts. (Ohms law).

[@JOHNPHUFNAGEL]

I had my helper shut off a breaker for 240v lights, I didn't think to tell him to shut both breakers off and he only did 1. I got an eye opening experience when I took the wire nuts off thinking that the power was completely off. Thanks for your videos!

[@Goldern]

240v on double single breakers? That’s crazy, should be a double breaker

[@w1swh1]

Thanks! My son told me about shared neutrals when I attempted to remove some aluminum wire in a panel that didn't seem to be doing anything. He said sometimes electricians use neutrals to save on wire and best left alone until the circuits can be checked fully. Panel is circa late 80's

[@LostInThe0zone]

My current home was built in the late 60s as a part of a 450 home subdivision. Without going into detail, I discovered that this technique was used in the construction of these homes. Once I learned of this, I was much more careful working on circuits in the house, but I will say that it's difficult to identify the other circuit that shares the neutral.

[@comrtnz]

Thats good to know. Just bought a house with older wiring and I tend to work basic repairs or replacements live. But never again until I make sure its 💯 safe.

[@-_.._._--_.-.-_-_-_-...-.-]

What an awesome dude! Passing out life saving information like it ain't no thing! Respect for that! And in a concise and captivating manner. Thank you! Job. Well. Done!

[@scotthill4742]

Great explanation!! Yes I’ve gotten a poke before 3 phase 347v because the wire nut was not on the wires properly. It came from the neutral. Hurts like an sob

[@elc2k385]

Dustin's videos are always exciting to watch.

[@CBrown07696]

I saw this on one of your best of videos and it was eye opening! Not allowed where I live but I see them in places I do work. Never considered overload of the neutral if both power wires are on the same bus.

[@amckimmey]

This is so helpful. I’m glad I stubbed upon this. I’m trying to figure out why there was a 12/3 coming from maybe the panel. Going to a bathroom and office.

[@beeps7]

Could be feeding a water heater in the ceiling.

[@allhoursmaintenance3022]

My house has that type of wiring. The cool thing is they soldered all multiple wires then taped no wire nuts, 1941 vintage. Nice video.

[@chrisfigueroa3361]

Awesome great explanation, but every time I work on circuits I work on them like it's hot all the time unless the main feeder breaker is off then I don't really care and even at that in my head I don't take any chances because I've seen a lot of bad stuff gone wrong with ppl working on circuits panels thanks for sharing be safe buddy 💯

[@christophermccord2757]

Thank you for this video. We are actually having to do this in some apartment buildings right now (they want all plugs on their own breaker, and it is in the blueprint to run them like this). Great info to k ow before we turn the power on.

[@toyotatacoma2021]

Yes we did mostly built 90 has share neutral at kitchen disposal and dishwasher so after we demo the kitchen. What we did is to make the breaker to be one pole with tanden has clip together with if the disposal trip they trip same time. Hoping mostly home owner got some tip between the share nuetral.

[@lelenbates3367]

I ran into this a decade ago. I was replacing an outlet an I checked the voltage from hot to ground and it was off. I found several neutrals in the box with a pig tail to the outlet . The pig tail was 14 ga with a 12 ga hot. I decided to change the neutral to 12 and when I disconnect the neutral bundle and it arced. Now I test everything with a non-contact tester.

[@davidmorton8170]

while those neutrals are bundled together, though, they will all be grounded and the non contact tester won’t show voltage. as soon as you pull them apart ( hence the arc) the wire still connected to the load is no longer pulled down and will then activate the tester. hopefully the other circuit has a hot wire in the same box that will clue you with the tester that it may be a shared neutral.

[@garyorlic3080]

Excellent video! I am constantly telling guys that electricity doesnt care about the color of the wire..... You have to understand its path not its color.

[@garretrobinson3668]

It’s pretty wild to hear Dustin mention my name. I’ve been watching the channel since I first got into the electrical trade and it’s been a huge help. I appreciate you sharing your knowledge and experience with the rest of us. Thanks!

[@chadg6874]

The only thing though is your comment needs to say "bruh" and is missing a 🤙

[@MrKen59]

Reminds me of switch loops and the measures electricians used in the 80’s to combine wires to save a few feet. Navigating the branches in a home from this era is a mess - fortunately they didn’t play the shared neural game in my house. On a side note - one example of a shared neutral application today would be to a main lug sub-panel.

[@TheRemyRomano]

Yep. That got me in my early days. I couldn’t figure out why in the hell I was getting bit by the neutrals when I obviously had the breaker for my circuit off. No one ever told me about it but I figured it out. 😂

[@andrewfischer8564]

yea we ran 12 /3/4 until very recently. on home runs we would pull three phases one neutral one ground. saved alot of room in the conduit, ment more circuits in a smaller pipe.

[@gabriely20]

I still see shared neutrals being used in new contruction for Dishwasher and Garbage disposal receptacle all the time out here in Az. I did not find in the NEC anything about those breaker needing to be tie together but it totally makes sense so Im going to start doing it. Thank you foe the awesome presentation

[@workingmanrondoyle3287]

Great video 👍. One thing that I keep finding in older homes I'm called to with shared neutrals. The neutrals shared with the red and black on the (same phase) which- could cause overheating/over current carrying conditions on the neutral wire.

[@keything8487]

i think that would keep the potential for 240v down.....still notta good idea

[@JPLaJeunesse]

In theory the phase is alternating so electricity flows in equal opposite times down the wire not doubling up, sometimes getting out of balance but the idea is they don’t heat the neutral more than the hot because of alternating current and also the load supplied has slightly less current coming back

[@workingmanrondoyle3287]

@@JPLaJeunesse I agree with most of what you said. But for the neutral carrying alternating current from shared red and black Has to be on separate/different phases for the neutral to carry the unbalanced load so as it won't overheat. Would be good video content as an experiment to prove this theory 🤔

[@anthonymwangi1661]

You are awesome man. Keep up doing what you do. Always feel appreciated. From Kenya.

[@calmeilles]

3:23 - "this part [of the neutral] won't [have current on it]". Correct, to a point. But it's still electrically connected to current carrying conductors. So if in touching it you create a nice path to ground you _will_ get a shock from it. Maybe only a little one, the comparative resistance of you and the return conductor likely results in you only experiencing a few volts. But just because a metal part is not forming an active circuit is not enough to assume it to be entirely safe. Oh. And GFCI breakers will soon show you if you have shared neutrals. The imbalanced current will make them trip quicker than you can say Romex! 😀

[@nobrizzle]

Thanks! This is an awesome heads up as I've never thought of that and am a novice to home electrical work. I have a very strange situation that led me to this video and in short, I have a 220v breaker turning on a 110v circuit (bathroom, etc.) and what looks like power fluctuations in some of the outlets & the oven. My uncle mentioned I have a "floating" neutral I need to find. He said that the neutral and ground wires are not supposed to connect/be shared anywhere except back at the sub-panel (I think) and his believes this is the source of the strange stuff I'm seeing and/or a neutral is being "borrowed" from another circuit. There was one of the main 100 amp fuses coming in from the street but he's saying that's not why I'm seeing the power fluctuations. A video about why you can't share a ground with neutrals would be great since that doesn't make sense to me why electrically it wouldn't work. It sounds like from this video it should work but it's just dangerous to work on live (not that I'd do that)? He's telling me I need to test each outlet/circuit to find the issue. I'm guessing I need to disconnect each and every neutral at the bus bar in the subpanel, then I can test for continuity between the grounds and neutrals at each switch/outlet to see where they are wrongly connected?

[@terryuland6502]

The neutral and ground must be bonded together once and only once at the point of first disconnect. If they are bonded together somewhere else, between that point and the first bond, the parallel paths cause current to flow on both the neutral AND the ground conductor in inverse proportion to the resistance of the conductor. (Just learned this myself while hooking up a portable generator to my main panel via breaker and interlock)

[@sirrussam6647]

Genius. Clear and concise description. You’re and excellent teacher.

[@jerrybennett9198]

One other thing happened when I was having my business rewired in an old 1937 commercial building with one, two or three businesses being housed in it over the life of the building. The electrical panels and wiring had been changed and upgraded (sometimes by amateurs) several times. The landlord had a supposed electrician come in and change the timer for the signs from one business in the building to another but the conduit to the sign was still in the first business location. The pseudo electrician took his power from the other business main panel but somehow left the connection of the neutral on the first business main panel, so there was a hot wire from one panel and the white wire from another main panel. So my commercial electrician who was installing whole new panel for my business shut all power off to my panel at meter. As he was pulling the main leads the hair went up on his arm near the neutral and he stopped immediately. The back feed was quite significant. Traced it to that old timer box. I think it was a once in his 15 year experience happening. Still when all power to the business is shut off and supposedly we all had our own meters, and main panels, i can see the mistake would be easier. But you have said always check for current even in a dead box. Jerry. PS Love your channel. Have watched most of your videos

[@AnitaBonita46]

A one-bedroom apartment was divided and converted into two studio units. I am unit A and my neighbor is unit B. We both have been living in the property for 4 years. A couple of months ago unit B has been having trouble with his outlets. Which affects my bathroom lights. Landlord refuses to fix the problem. And Unit B refuses to get extension cords and fix the problem as well. I am being forced to either give unit B a key to my unit in case I'm not home to access the circuit breaker. Or landlord threatened to evict both of us, if we don't work together in regards to this issue 🤷

[@wolfman_jagermeistro8445]

Report him.

[@paulmac3307]

Sue the landlord immediately with an attorney's letterhead.

[@AnitaBonita46]

@@paulmac3307 ended up being that unit b was doing it on purpose cuz he was behind on his rent. Told the landlord he's moving out because I'm a bad person. 3 months later a new tenant move in and I haven't had that issue again. 😆😆😆

[@R900DZ]

Fantastic coverage of this topic, thanks!

[@buzzaard7036]

A secondary path can also be from Satellite or Cable service as the coax cable is directly bonded to the ground outside which can be an alternate path that can get you if there is any bleed through on the power packs or the devices themselves. If you ever have a customer tell you the Cable guy asked if their lights flicker or point out the coax is melting you have a potential open neutral or a bad connection in a box where someone was able to get 5 wires in a 3 wire wire nut or something similar the coax used should have no voltage when measuring from neutral or ground at the outlet to the metal connector of the cable jack, coax is also not rated to carry current but will until it cant anymore.

[@PhinAI]

Important to think about during ballast replacements in 277V applications in large rooms with rows of lighting fed by multiple circuits. I'm sure there's nothing like having a hot neutral fall off of the fixture your working on into your ear or eye while standing on a ladder.

[@docferringer]

277 is a bit harsh for beginners. Start 'em off with a 120V lighting circuit with the switch on the neutral side, then leave them unattended while the old "I turned off the switch do I really need to turn off the breaker too?" argument plays out in their heads.

[@jeffdutton1910]

in the course of retiring some old cables in my house I found a ceiling light fixture with 2 circuits in the box. The light was controlled through a switch at either end of the staircase. Whoever wired it originally ran 14/2 between the switches, so at the light fixture there was no neutral available...until he brought in another circuit and tapped the neutral. It made my blood run cold. On a later renovation project we had the cable running between the switches exposed as the drywall was off, so I was able to replace the cable run.

[@chrislester3152]

Hey I think your videos are great for beginners and I think you have a great way for normal people to understand things, I’m hope you could help clarify some more about two hots one neutral, because of the video about running cross overs from 120 volt generators, to a panel . So I’m wandering about wouldn’t that be same as adding the Amps of all the loads the generator pushes and would it double the amps on the neutral back to the generator, Any thoughts would be helpful and thanks

[@travishatch4303]

I have one. Re wireing old house, had 3 breakers on, so 3 live circuits,. one for the single outside outlet, (which i put in at the main box), one ran to the shed (easy to tell) and one ran inside for a total of 3 outlets, all rewired by me from what i thought was the beginning of the circuit (i spliced from the floor, near the main box, and terminated at the last oulet). As i was trying to trace wiring for a individual lighting circuit, i went to snip romex tied and taped into knob and tube, (in the ceiling) and accidently crossed the netual and hot on the romex and, yup, sparks. Tripped the breaker. Now heres the kicker. I flipped the breaker back on, and went testing becuase that line should not have been live. Turns out, with only the one breaker i installed for the first 3 outlets turned on, apparently most if not all my house had 120v, or say 5v or 6v without a load introduced. So i have been messing with wires and around wires and etc all summer as i was doing demo and such, never tried testing them because well, all the breakers were off. How does my house have power throughout, on one 20 amp breaker. ? Why am i getting readings of 5v at places, but as soo. As i plug in something, its 120v? (Little house, around 700sq ft)

[@svinnthefallen1486]

Sawmill tech here. You should cover ground loop when dealing with a short to one side of a "space saver". I had a light switch cover plate that had 110v to ground after removing it from jbox. And the switch was. In good working order.

[@havemercy]

Was the sawmill supplied by an ungrounded delta transformer?

[@Cnightz]

I just fixed a wiring issue in my house that had this problem, but a more severe violation. 14/3 wire running 6 rooms upstairs. Every neutral receptacle was discolored or burned. I fixed it myself Raj 2 home runs to separate junction boxes.

[@COTU9]

That was a great explanation. The white board work was really helpful. Thanks.

[@spanny52]

Shared Neutral shocks are the worst! Thanks for the video!

[@kinchu007]

"Now you have a 240V shock on your hands" classic!...loved the video thanks

[@InquisitiveSearcher]

Once I went to work on just a simple light. Rather than going through the trouble of finding the breaker in an unmarked box I thought I would just turn off the light switch and I'd be safe. But nope, I got bit with a fairly strong sting, but not a full load that I would expect from 120. After watching this, I'm guessing that it was some sort of a feedback through neutral from another device on the line/circuit that was turned on. Very interesting. (always trip the breaker!)

[@jbontra2]

Recently had a situation that they had run 12/2 and tied the neutrals together in another switch box. We we’re replacing a bathroom outlet with a GFCI ( place was built in the early 70’s ). Couldn’t get the GFI to set. I had to start running down the wires in the other places that the power went out with that breaker. Found the neutrals tied together in a switch box.

[@Sparky-ww5re]

Not only have I gotten bitten by a neutral, when I was a teenager I got shocked off an electric water heater. Changing out an element. Uncle Gary turns off the breaker and tells me it's off. Of course I verified the power was off with a multimeter that I tested on a known live circuit. I tested across the terminals on the upper thermostat, but didn't think to check each leg to ground. What happened was there were two single pole 30s in the panel which has been there since probably the 50s or 60s. If memory serves me right the two 30 amp breakers were not even near each other, just randomly placed. Talk about some shady work.

[@cleanpowerelectric]

Well now i have to go up to my fishing cabin and install a tied pair of breakers. Thanks, learn something new every vid.

[@patrickzavas]

Most commercial projects my employer had us run one neutral per 3 conductors on a three-phase panel. All of these loads were calculated and balanced of first to the best of our ability

[@j2o3sh]

You wouldn’t believe how many electricians I work with that don’t know this lol. I try and explain it to them and it isn’t getting through…. I’ll show them this . Good video!

[@kourbinrogers8328]

I learned this the hard way. I missed one neuty under a wire nut on a 3 phase 277v lighting system. I turned all 3 breakers on and lit up all the fixtures downstream of that missed wire with 480v. Fried the drivers, and the tuners.

[@jaydee3046]

I had a 200 amp panel installed and noticed there many joined cicuit breakers. Asked the electrician about it, and he said our state (CA) now requires that setup. When I asked about troubleshooting just one circuit breaker, he said go ahead and pull the tie off.

[@frankcarone3657]

It's a significant savings when you are doing a big job. In Chicago We can put 9 wires in a conduit, that would be (6) 3 wire circuits or only (4) 2 wire Circuits. We use a 2 pole breaker and use a wire tie to bind the three wire circuit together where it enters the panel. When connecting power poles in office cubicles and outlet buss ways, they are all wired from the manufactures with 3 wire circuits, so they are a necessary evil. If you have a lot of expensive electronic equipment, 2 wire circuits are best practice.

[@fernandofrancisco3106]

Thanks for great info. Always appreciate your advice.

[@OtisPlunk]

I always anticipate that something won’t be correctly done. Just found multi wire branch circuits run from a quad-breaker with the ever popular handle tie delete option. Eaton quad handle ties fit nicely on Murray quads. I always expect Neutrals to go live when unbuttoned until I check them with my chicken-stick post disconnect. I think Uncle Fester used a lost panel neutral to energize his light bulb.

[@B29guy1]

LOVE your information!! LOVE your insight. Thank you for all that you do. Since the 1960's, I have been repairing vacuum tube electronics. The very main thing to do is to isolate the hot to common by replacing the "death caps" and installing a polarized plug. I like the 2 prong that only fit pole outlets. I get many comments that I am wrong by not using 3-prong, however, I do not want to ground the common at the outlet. Am I wrong? Should I be better by using a 3 and leave the ground prong open? Is the 2-prong polarized still the best in your opinion? (I'm sure that the common is energized regardless of what plug is used, anyway). THANK you MUCH!!

[@robertshivers7156]

question on any kind of 10/3,12/3,14/3 aren't the hot conductors supposed to be landed on a 2 pole breaker to keep you from getting shocked off the neutrals?

[@Forest0922]

@7:45 So this is actually a really common misconception. If you are using two 1 pole breakers with a handle tie that does not mean they are common trip. What makes a breaker common trip is actually an internal mechanism on factory 2 pole breakers with the common trip feature. If we have a 1 pole 15A circuit for example and I hold the breaker closed and someone shorts it downstream it will still trip and kill the circuit even though it's being held closed, hence trip-free breakers. We can actually see this in the UL 489 certification with the following: Independent Trip - A 2-pole circuit breaker that does not have an internal common trip feature is marked “Independent Trip” or “No Common Trip.” An external handle tie alone does not qualify as a common trip mechanism - a breaker of this type is marked to indicate it is an independent trip breaker. The main point of the handle tie with multiwire Branch Circuits is to make it so if someone actually moves the handle both circuits will open/close together. It's also to make it so that if some other electrician shows up who didn't do the original work, they see the handle tie and look and know it's a multiwire circuit and to be careful. If we have two 1 pole breakers in good condition there is a good chance, they still will trip but it's not guaranteed and if the breakers are older and stiffer, they probably won't trip. If you read 210.4 (B) (B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates. Doesn't actually mention anything about the trip.

[@anthonypicozzi4414]

You know I feel you should teach these guys about the back seats. I had a panel today. I forgot to check the leg. It was the a leg. I put it on the c-phase put the breaker on and boom 🤯 lol

[@ratbag359]

happens sometimes with 2 way switching e.g upstairs downstairs the light in the stairwell maybe connected to the upstairs neutral while the phase/live/active/hot feed is coming from the downstairs lighting feed. in this situation the light will have to be on but two situations can causes a shock on is pulling the upstairs neutral out at the fuse board and the other is touching live conductors in the upstairs switch or light fitting. in our older houses the second switch did not contain a neutral or earth which makes testing for voltage hard.

[@jaylee8542]

This actually happened to me on a shut down. We were replacing a set of gear and had all the conductors disconnected. Both sides of the mains were locked and tagged out. I was wedged inside the gear, assembling the neutral buss. All at once the gear became energized and I was getting the shock of my life. While the system we were working on was locked and tagged, there was a neutral somewhere in the building that was tapped in to what we were working on. A time clock had came on and some of that unbalanced load came back through the feeders that terminated in the gear we were in. Coincidentally, three phases that we had tied up had floated over and were touching the gear. That was the first time I went home and thought about never going back.

[@extremekilla316]

Wow glad you’re okay

[@Goldern]

Ground the neutral and then that shouldn’t happen

[@sunbrookheath]

I have one of these situations in my laundry room I believe. Two outlets one for the washing machine and one for the dryer (gas). I was replacing the outlet for the washer (it's breaker was off) and got a slight shock. Turned off the breaker for the dryer and continued working no problem. Would this be done because those appliances touch when placed side by side as a fail-safe if one of them has an issue?

[@MD-en3zm]

120V drier? Like a gas drier with a 120V?

[@alphaforce6998]

For those people wondering why even do this, the answer is simple: a shared neutral lets you run a single three-wire conductor for two dedicated 120V circuits. So you are essentially halving your wiring material costs. It is called a branch circuit, and it works by connecting the "hot" wires to each of the two 120V legs at the breaker, as you would for a 240V circuit, but when you wire the outlets, instead of having two hot wires go into the outlet you share the neutral between them. But wont that overload the breaker if you did this with 20A breakers? If you draw 20 amps from both circuits, won't that be like 40 amps on the shared neutral? No, because the two legs are out-of-phase, and as such, the current flowing on the shared neutral will max out at 20 amps, as the phases are inverse and cancel each other out. In other words, the neutral wire never sees more than 20 amps even if both of the circuits are power some high-current appliance like an oven or portable AC.

[@nussbaumjm]

Hey man, love the videos. Keep it up. What Code section covers the handle tied breaker?