# How to test if shared neutral is live?



## vhk

Hello, 

I'm working in a building where there are some circuits (3 phase 347/600v circuits) that share a neutral. The junction box I'm working on has one live circuit with neutrals spliced, I already shut the live wire off, but unsure if the neutral is shared or not, and want to test it. The non contact voltage tester doesn't work on live shared neutrals of course, but using a multimeter will only show little to no voltage on a neutral. So what's the best way to determine if a neutral is completely dead?


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## CoolWill

vhk said:


> Hello,
> 
> I'm working in a building where there are some circuits (3 phase 347/600v circuits) that share a neutral. The junction box I'm working on has one live circuit with neutrals spliced, I already shut the live wire off, but unsure if the neutral is shared or not, and want to test it. The non contact voltage tester doesn't work on live shared neutrals of course, but using a multimeter will only show little to no voltage on a neutral. So what's the best way to determine if a neutral is completely dead?


Hang a clamp on meter and see if there is current flowing.


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## Bird dog

Are you an electrician, an apprentice, a maintenance person or something else???
Please fill out your profile.


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## gpop

even a zero amp unless you can prove the neutral is dead then you treat it as a live wire and use PPE.


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## macmikeman

..........


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## macmikeman

.............


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## micromind

Easy.....cut it and if something burns up, it was live.......

Seriously, I don't know of any way to know if it's carrying current or not. If the current is very low, a clamp-on won't read it.


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## sparkiez

You start by tracing out the wires for A, B, C phase to a point of disconnect and shut off all three phases. They should be on either a 3-pole breaker or 3 single-pole breakers with approved handle-ties, but being realistic here, they probably aren't.


Then you still cap it and treat it as if it is live. You can verify dead following proper procedures.


More importantly, is no one around to teach you this?


Also, you shouldn't be working with a circuit at those voltages, and likely ampacities...


IT


WILL


KILL


YOU


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## MechanicalDVR

Welcome aboard @vhk!

Thanks for filing out your profile.

I'm of the camp that this should have been explained by your journeyman, if you came here I figure you aren't comfortable asking or he's not easy to ask questions.

Always ask questions, it's a part of learning.


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## glen1971

sparkiez said:


> You start by tracing out the wires for A, B, C phase to a point of disconnect and shut off all three phases. *They should be on either a 3-pole breaker or 3 single-pole breakers with approved handle-ties,* but being realistic here, they probably aren't.
> 
> 
> Then you still cap it and treat it as if it is live. You can verify dead following proper procedures.
> 
> 
> More importantly, is no one around to teach you this?
> 
> 
> Also, you shouldn't be working with a circuit at those voltages, and likely ampacities...
> 
> 
> IT
> 
> 
> WILL
> 
> 
> KILL
> 
> 
> YOU


Not required in Canuckistan.. But very important to determine which hots they are, because as you mentioned it will kill you. 347 is nothing to mess around with.. Is the wiring labelled? The neutrals may be labelled to help determine which hots are included. Is it ran in a conduit that can be traced, so that you narrow down your search?


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## vhk

Thanks for the responses everyone. First of all, I'm posting here not because I'm unsure or afraid of asking my Jman, I'm posting here because it appears a lot of people at my work, as well as other electricians I ask, don't seem to know how to test for a live neutral right on site without having to go through the trouble of identifying if a neutral has all the phases shut off.

First of all, I'm mostly working commercial service. A lot of places I go to involve large downtown buildings where 347v lighting is prevalent. The buildings are quite old, so the neutrals are not labelled as to what hots are sharing them, both at the JBs and panelboard. There are hundreds to thousands of people working in these buildings., so a lot of times we are expected to service live circuits without inconveniencing the people working inside. Current job I have to do is removing old 347v lighting and their corresponding BX whips from the JBs. 

The JBs contain a bunch of neutrals spliced together. I already shut off the hot for the light themselves, but wanted to see if the neutral is completely dead before I break apart the neutrals. My Jman mentioned to me I just put a clamp meter on the neutral, but I know it doesn't work if the current is low enough. The circuit is #2 on the panelboard, and I know typically shared neutrals go sequentially like 2,4,6 - N, or 2,4-N, etc. But shutting off the other breakers would either shut off lighting to most of the building with people inside, and it may not guarantee the neutral is dead, as #2 can be shared with #10,#12, for example. Panelboard and JBs have no labeling. Conduit and wires cannot be traced due to the layout of the building. That's why I want to know what's the best way to ensure a neutral is dead, right on site.


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## vhk

Just to add, I was able to shut off the breaker for those lights, just because that entire floor of the building happened to be vacant, so nobody was inconvenienced, but the rest of the floors are occupied.


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## joebanana

If you're just demoing lights, cut the neuch for the whip your working on at the connection leaving yourself enough sticking out of the wirenut to cap with a yellow, or tape it. No need to open the splice. Just don't ground yourself while cutting.


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## sparkiez

joebanana said:


> If you're just demoing lights, cut the neuch for the whip your working on at the connection leaving yourself enough sticking out of the wirenut to cap with a yellow, or tape it. No need to open the splice. Just don't ground yourself while cutting.



This isn't wrong, but it makes me damn uncomfortable sending someone who hasn't been trained to deal with this high-energy of a circuit...


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## CoolWill

F those bunch of desk riding sissies. "Inconvienced". I'm the last guy to preach about working live, especially on 20 amp lighting circuits. I do it all the time depending on the situation. None of those situations are ever because it inconviences someone in front of a computer. Turn it off.


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## Bird dog

CoolWill said:


> F those bunch of desk riding sissies. "Inconvienced". I'm the last guy to preach about working live, especially on 20 amp lighting circuits. I do it all the time depending on the situation. None of those situations are ever because it inconviences someone in front of a computer. Turn it off.


If he falls off the ladder, he'll be fired before he hits the ground. :sad:


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## zac

And charged with trespassing when he hits the ground! 

Sent from my SM-G950U using Tapatalk


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## just the cowboy

Just don't open the circuit. Do as Joebanana says just cut the whip wires and nut it. Opening the circuit can send mixed voltages to the load.


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## sparkiez

I've been at this a while, and you won't catch me working a 600V phase to phase circuit hot. Either people are working in the dark or I'm getting double time to do it during the off-hours. Not long ago a kid died hanging exit lighting. He graduated from a trade school, the company lied to him about being a registered apprentice. He was listed as a laborer. They ****ed him over, he wasn't being supervised, and now he is dead.


Hearing something like this makes me want blood.


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## Incognito

sparkiez said:


> I've been at this a while, and you won't catch me working a 600V phase to phase circuit hot. Either people are working in the dark or I'm getting double time to do it during the off-hours. Not long ago a kid died hanging exit lighting. He graduated from a trade school, the company lied to him about being a registered apprentice. He was listed as a laborer. They ****ed him over, he wasn't being supervised, and now he is dead.
> 
> 
> *Hearing something like this makes me want blood*.


Me too. No one should be working on live circuits unless your licensed and only troubleshooting. Definitely should not have a brand new worker doing it.


Just to clarify, he did not graduate from a trade school. He paid for a money grab, pre apprentice scam of a school where everyone graduates as long as you pay. They charge $9000 for 3 month program that gets you nothing. No hours toward a real apprenticeship, no real trade school exemptions. 

Sorry, these pre apprentice money grab scams are a bit of a trigger for me.


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## vhk

joebanana said:


> If you're just demoing lights, cut the neuch for the whip your working on at the connection leaving yourself enough sticking out of the wirenut to cap with a yellow, or tape it. No need to open the splice. Just don't ground yourself while cutting.


This is exactly what I've been doing. Plus I wear Class 00 gloves with leather gloves on top for good measure, especially when I have to shove a bunch of spliced wires into a 4x4 box (they're 347v). I have many of my colleagues suggested doing this. However, just like most of you here, no one really knows how to test if a shared neutral is live.

Also I've been a bit of a long time lurker, I've noticed a bunch of people here strongly advising not working on live, yet an equal number of people suggesting you're not a real electrician if you cannot work on live.

For me, it took me a while to get over the fear of working on 120V live at first. For me to do it comfortably, I had to watch someone else do it. Everything from changing a receptacle live, splicing a bunch of hots together, splicing neutrals together live (with 120v, its not a big deal), and tying circuits into a live panel. All of this freaked me out to the core and people had to educate me on how to handle electricity properly. Obviously 347v is a different beast altogether, and I'm kind of surprised there really isn't a method to detect a live neutral aside from taking precautionary measures like cutting the neutral off a bx whip as someone suggested and capping it off.


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## sparkiez

Incognito said:


> Me too. No one should be working on live circuits unless your licensed and only troubleshooting. Definitely should not have a brand new worker doing it.
> 
> 
> Just to clarify, he did not graduate from a trade school. He paid for a money grab, pre apprentice scam of a school where everyone graduates as long as you pay. They charge $9000 for 3 month program that gets you nothing. No hours toward a real apprenticeship, no real trade school exemptions.
> 
> Sorry, these pre apprentice money grab scams are a bit of a trigger for me.



I've seen a guy that went through a program like this. He paid $30k for a TWO YEAR DEGREE and he wasn't half as capable as I was with my fully accredited AAS in Mechatronics. I busted hump and got scholarships. I actually made about 1.5k per semester to go to school provided I maintained my grades for the last 3 semesters. All-in-all, the degree costs about 10k with me getting pre-reqs out of the way for engineering school.


I preach against them just as heavily. It sucks when these kids come out thinking they are learning something when they really aren't.


That aside though, this kid *thought* he knew what he was doing. There is a place in the acquisition of knowledge where you don't know what you don't know.


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## joebanana

vhk said:


> This is exactly what I've been doing. Plus I wear Class 00 gloves with leather gloves on top for good measure, especially when I have to shove a bunch of spliced wires into a 4x4 box (they're 347v). I have many of my colleagues suggested doing this. However, just like most of you here, no one really knows how to test if a shared neutral is live.
> 
> Also I've been a bit of a long time lurker, I've noticed a bunch of people here strongly advising not working on live, yet an equal number of people suggesting you're not a real electrician if you cannot work on live.
> 
> For me, it took me a while to get over the fear of working on 120V live at first. For me to do it comfortably, I had to watch someone else do it. Everything from changing a receptacle live, splicing a bunch of hots together, splicing neutrals together live (with 120v, its not a big deal), and tying circuits into a live panel. All of this freaked me out to the core and people had to educate me on how to handle electricity properly. Obviously 347v is a different beast altogether, and I'm kind of surprised there really isn't a method to detect a live neutral aside from taking precautionary measures like cutting the neutral off a bx whip as someone suggested and capping it off.


The thing with shared neutrals is, if the loads are balanced, there is no current on the neutral, and no voltage because it's at ground potential. But opening it can put phase to phase voltage on 2 separate phase to ground loads. That's bad for computers, and lights. 

The main thing you HAVE to remember when working with shared neutrals is to not ground yourself, that means to "T" bar, cement floors, tile, ceiling wires, conduits, fixtures, etc. "T" bar grid is a mother father to work around when you have some live and some not in the same box. Another thing to remember is to keep the wires in control. Don't let them "flop" into a box, or you when you take off wirenuts. Tape is your friend.


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## Southeast Power

I've been in the trade for almost 40 years and can vividly remember every single time I was hit with 277. Every one of them was within the first 10 years in the trade. That's when I knew everything. :vs_laugh:

I also hate when 277 lighting circuits blow up in your face too. 
I turn it off or find a very safe way of doing the job.


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## LibertyRising

I’m in the camp of turn off the power. I am not scared of electric shock, but I do respect it- 14 years in the field, and I used to think it was some bad ass if I fixed a problem live. But as time grows on I realie that there is no reason to take repeated risks on a large job like that. Shut it down. If things are so badly labeled you have no idea, it needs to be brought to the supervisor’s and safety manager’s attention. In writing if you are smart. That way when you get electrocuted and killed your family can sue and make some money. 

The only safe way to do this is to shut down power. Convenience is secondary to safety.


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## macmikeman

LibertyRising said:


> I’m in the camp of turn off the power. I am not scared of electric shock, but I do respect it- 14 years in the field, and I used to think it was some bad ass if I fixed a problem live. But as time grows on I realie that there is no reason to take repeated risks on a large job like that. Shut it down. If things are so badly labeled you have no idea, it needs to be brought to the supervisor’s and safety manager’s attention. In writing if you are smart. That way when you get electrocuted and killed your family can sue and make some money.
> 
> The only safe way to do this is to shut down power. Convenience is secondary to safety.


This is what cracks me up about people who say they could not find the circuit in a badly labeled residential panel. I can find it. It's called the main breaker. Turn it off if you have any doubts about which circuit is controlled by what breaker. Then work on the circuit. Applies even more in commercial work, and I'm fairly certain even more than that in so called industrial work. Higher voltages are very unforgiving. And the potential to deliver a lot more amps to the short circuit or ground fault grows exponentially with the larger facilities. This ain't no place to be making short circuits or being in the proximity during an arcing event.


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## Weasel

SoutheastPower said:


> I've been in the trade for almost 40 years and can vividly remember every single time I was hit with 277. Every one of them was within the first 10 years in the trade. That's when I knew everything.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I also hate when 277 lighting circuits blow up in your face too.
> I turn it off or find a very safe way of doing the job.


more people are killed working on 277vac hot. Cut it off


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## Weasel

Put an amp probe on it or ohm it to ground


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## glen1971

Weasel said:


> Put an amp probe on it or ohm it to ground


Unless I'm misunderstanding you, what good would ohming it to ground do? If it's by itself or shared, you'll see it as a short to ground (assuming the panel end is properly bonded).. If it's shared, and you disconnect it, you'll run that current through your meter to ground..


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## sparkiez

glen1971 said:


> Unless I'm misunderstanding you, what good would ohming it to ground do? If it's by itself or shared, you'll see it as a short to ground (assuming the panel end is properly bonded).. If it's shared, and you disconnect it, you'll run that current through your meter to ground..



Ohming to ground would accomplish nothing, I agree.


Putting an amp clamp on it accomplishes little. You can have that neutral carrying little to no current but the entire situation changes when you open a phase.


I'm going to go ahead and say here that it is my belief that this is incorrect information and/or bad advice and OP should disregard it.


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## Weasel

I meant to say measure with your meter the neutral your are talking about will show voltage if it is shared neutral and has a load on it


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## Incognito

Weasel said:


> I meant to say measure with your meter the neutral your are talking about will show voltage if it is shared neutral and has a load on it


???

It will always have voltage, load or no load


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## glen1971

Weasel said:


> Put an amp probe on it or *ohm it to ground*





glen1971 said:


> Unless I'm misunderstanding you, what good would ohming it to ground do? If it's by itself or shared, you'll see it as a short to ground (assuming the panel end is properly bonded).. If it's shared, and you disconnect it, you'll run that current through your meter to ground..





Weasel said:


> I meant to say measure with your meter the neutral your are talking about will show voltage if it is shared neutral and has a load on it


Where did I say to test for voltage on the neutral? You said to ohm it to ground. Unless I'm missing it, "ohming to ground" tells me that you want your meter set on omega and are trying to measure resistance to ground. If you try this stunt and and you have broken a shared neutral on the homerun side, you're meter will take the fault current through it when you go from ground to a neutral...

Why is it so tough to isolate the circuits and do it properly? He11 isolate the main for the time it's gonna take. Do it on a Saturday.. After hours.. Whatever it takes...Let me know what Z462 tells you about working live on a 347 volt LIGHTING circuit so you didn't have to interrupt someone's work day..


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## gpop

glen1971 said:


> Why is it so tough to isolate the circuits and do it properly? He11 isolate the main for the time it's gonna take. Do it on a Saturday.. After hours.. Whatever it takes...Let me know what Z462 tells you about working live on a 347 volt LIGHTING circuit so you didn't have to interrupt someone's work day..


Its not tough to isolate the circuit by turning off the breaker. Its tough to prove that you have isolated the circuit which causes a problem. 

Something like a nightlight circuit bugged of a the wrong neutral can cause a surprise so treat the neutral as a hot and use ppe. (after years of upgrades just about any other circuit could be bugging the neutral)

Im glad i invested in a quality tracer years ago. Simply clamp the ring over a wire dead or alive and it will be easy to find in the panel.


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## LibertyRising

I just don’t understand why in the OP’s situation you aren’t stopping work and demanding the customer pay to bring the electrical distribution up to code? If shared neutral circuits are running amok, and not labeled, it’s a choice to make to either ignore it and take the liability of burning up some ballasts, or worse - hurting someone, or you can make some money and force the business to install the correct breakers that shut off all the phases of a shared neutral circuit. 

It’s not bad business to stand up for safety and minimize risk.

I had a repair job at a local papa johns, the existing wiring was all wrong and needed to be brought up to code. I refused to fix it as it was, and at the end of the day, I win. Either I am not liable for bad work, or I make money fixing something that needs to be fixed.


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## CoolWill

LibertyRising said:


> I just don’t understand why in the OP’s situation you aren’t stopping work and demanding the customer pay to bring the electrical distribution up to code? If shared neutral circuits are running amok, and not labeled, it’s a choice to make to either ignore it and take the liability of burning up some ballasts, or worse - hurting someone, or you can make some money and force the business to install the correct breakers that shut off all the phases of a shared neutral circuit.
> 
> It’s not bad business to stand up for safety and minimize risk.
> 
> I had a repair job at a local papa johns, the existing wiring was all wrong and needed to be brought up to code. I refused to fix it as it was, and at the end of the day, I win. Either I am not liable for bad work, or I make money fixing something that needs to be fixed.


Except for the fact that using handle-tied breakers for three different circuits is stupid.


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## gpop

LibertyRising said:


> I just don’t understand why in the OP’s situation you aren’t stopping work and demanding the customer pay to bring the electrical distribution up to code? If shared neutral circuits are running amok, and not labeled, it’s a choice to make to either ignore it and take the liability of burning up some ballasts, or worse - hurting someone, or you can make some money and force the business to install the correct breakers that shut off all the phases of a shared neutral circuit.
> 
> It’s not bad business to stand up for safety and minimize risk.
> 
> I had a repair job at a local papa johns, the existing wiring was all wrong and needed to be brought up to code. I refused to fix it as it was, and at the end of the day, I win. Either I am not liable for bad work, or I make money fixing something that needs to be fixed.


No one has said its not up to code. It could be well marked and look perfect.

Once the breaker is turned off it probably is safe but can you prove it unless you unhook it.

The point of this post was to ask if there was a way to double check and test the neutral while its still connect to the panel.

As there is no way to test it then you treat it as a live wire.


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## sparkiez

CoolWill said:


> Except for the fact that using handle-tied breakers for three different circuits is stupid.


It doesn't matter if you think it is stupid, it is required by code.


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## LibertyRising

CoolWill said:


> Except for the fact that using handle-tied breakers for three different circuits is stupid.


How is it stupid? In the panel he will see which wires are shared neutral. At that point if he was to install a double or 3 pole breaker for each shared neutral circuit, he would then know without a doubt that when he turns off the breaker that he will have killed all the circuits sharing the neutral, eliminating the risk. 

I ask again, what is stupid? Playing a guessing game with live circuits, or ensuring that the installation is up to code?


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## LibertyRising

gpop said:


> No one has said its not up to code. It could be well marked and look perfect.
> 
> Once the breaker is turned off it probably is safe but can you prove it unless you unhook it.
> 
> The point of this post was to ask if there was a way to double check and test the neutral while its still connect to the panel.
> 
> As there is no way to test it then you treat it as a live wire.


It is clearly not marked properly or installed to code if the OP cannot be sure the neutral is dead if the ungrounded conductor is dead. 

(B) Disconnecting Means. Each multi-wire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.”

What's so hard to understand that there is no need to test if the neutral is live if you have first verified all the ungrounded conductors are being disconnected at the point the branch circuit originates?


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## CoolWill

sparkiez said:


> It doesn't matter if you think it is stupid, it is required by code.


It isn't required by code in Canada where the OP is. Nor is it required by the NEC to make existing installations up to current code.



LibertyRising said:


> How is it stupid? In the panel he will see which wires are shared neutral. At that point if he was to install a double or 3 pole breaker for each shared neutral circuit, he would then know without a doubt that when he turns off the breaker that he will have killed all the circuits sharing the neutral, eliminating the risk.
> 
> I ask again, what is stupid? Playing a guessing game with live circuits, or ensuring that the installation is up to code?


It's another stupid rule made by manufactures. Millions of existing installs are perfectly fine.


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## HackWork

LibertyRising said:


> I just don’t understand why in the OP’s situation you aren’t stopping work and demanding the customer pay to bring the electrical distribution up to code? If shared neutral circuits are running amok, and not labeled, it’s a choice to make to either ignore it and take the liability of burning up some ballasts, or worse - hurting someone, or you can make some money and force the business to install the correct breakers that shut off all the phases of a shared neutral circuit.
> 
> It’s not bad business to stand up for safety and minimize risk.
> 
> I had a repair job at a local papa johns, the existing wiring was all wrong and needed to be brought up to code. I refused to fix it as it was, and at the end of the day, I win. Either I am not liable for bad work, or I make money fixing something that needs to be fixed.


 The requirement for handle ties for MWBC’s was in the 2008 NEC, which most areas adopted years after that. 95% of the electrical installations I work on were installed far before that requirement.

Are you really trying to say that I should demand every single one of those installations is brought up to current code? What about all of the other issues? There could be dozens if not hundreds of other things that aren’t up to current code. Do we re-wire every house and building we have to work in?

I just don’t understand.


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## sparkiez

I didn't say anything about bringing an install up to current code. I said having a common trip for ungrounded conductors in a multiwire branch circuit is required by code. It doesn't matter in the least what you think until you start making the codes.


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## CoolWill

sparkiez said:


> I didn't say anything about bringing an install up to current code. I said having a common trip for ungrounded conductors in a multiwire branch circuit is required by code. It doesn't matter in the least what you think until you start making the codes.


Right. Liberty Rising said it, then you chimed in. It is required by code for NEW circuits since 2008. Existing circuits is what we are talking about here. Millions upon millions of multiwire branch circuits are out there functioning just fine without handle-tied breakers, and have been for 100 years. 

If someone is too scared or incompetent to work on an MWBC without throwing a tantrum and demanding the customer unnecessarily upgrade to current code, they should go back to being a plumber.


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## gpop

LibertyRising said:


> It is clearly not marked properly or installed to code if the OP cannot be sure the neutral is dead if the ungrounded conductor is dead.
> 
> (B) Disconnecting Means. Each multi-wire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.”
> 
> What's so hard to understand that there is no need to test if the neutral is live if you have first verified all the ungrounded conductors are being disconnected at the point the branch circuit originates?


So you never test and just presume that a mistake has never been made. Now that old school work it live mentality.


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## macmikeman

I have seen many a 3 phase panel with a full boat spaced so that the hot conductors were properly spaced on A, B , C phases such that the neutral didn't get overloaded. They just weren't next to each other is all.....................


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## Incognito

CoolWill said:


> It's another stupid rule made by manufactures. Millions of existing installs are perfectly fine.



Come on, you seriously think that code was brought on by the manufacturers? How many millions in extra profit do you suppose they will make in the sales of handle ties? How much money do you think they would have to spend in trying to get a code changed for their benefit?


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## emtnut

sparkiez said:


> I didn't say anything about bringing an install up to current code. I said having a common trip for ungrounded conductors in a multiwire branch circuit is required by code. It doesn't matter in the least what you think until you start making the codes.


You're a young 'un , right :biggrin:

CEC doesn't have that requirement (and even I know that NEC only started that in 2008, and I'm a canuck ! )

Maybe igloos don't burn as easily thou ?? :surprise:

:vs_laugh:


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## catsparky1

If you can't play with the spark then don't . If you do know how to play with MWBCs then don't . I know how and will continue to play all day everyday and will lead my crew into battle with that knowledge . I don't know who has taught some of you but they did it wrong .


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## CoolWill

Incognito said:


> Come on, you seriously think that code was brought on by the manufacturers? How many millions in extra profit do you suppose they will make in the sales of handle ties? How much money do you think they would have to spend in trying to get a code changed for their benefit?


Not for handle ties, no. But why would anyone install MWBCs now? It is so stupid and inconvenient for multiple circuits to go down if one trips or needs to be services. So instead we install individual neutrals now. The number of neutrals has now tripled (for 3 phase) and more pipe is required.


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## macmikeman

*Testing the neutral on a well balanced 3 phase full boat circuit.* The neutral may show zero amps with all three phases running. If it is not a motor load but it's three lighting circuits like you find in large stores, turn the switch for one row off, and check amps on the neutral. It will now show current on the meter. Flip the switch for the de-energized row of lights back on and the meter reads zero again. 
Don't open that neutral connection till you turn off all three of the hot lines at the breaker panel. As I have already noted in this thread, they might not all be next to each other, be careful. Use your eyesight to trace all three wires from the entry point conduit in the panel to the breakers they land on. If all land in a three pole breaker you are certainly in luck and you can shut that off and then it's safe to open the neutral wire up. 
When it's a three phase motor load (hardly ever needs a neutral anyhow.....) you need to find the correct circuit breaker for all three phases of the load and turn them off at the same time. 99.99 times out of a hundred when it's motors it will be a three pole breaker. Let us ignore that .001 time it's not. Shut the motor controller off and the motor will stop running. Then turn off the proper circuit breaker. This sequence is to avoid arc at the point of disconnection, and also to avoid breakdown of the motor and machinery itself. Now you know your neutral is dead and it can be safely opened , (especially if you follow proper lock out and tag out procedures). I don't often find neutral wires for 3 phase motors , but they can be used to prevent phase drift and to ensure a good current return path, and also for control wiring , so maybe I just work on the wrong machines all the time. User experience may differ. 

The amp clamp should always be used on the neutral wires before opening the connection points downstream of the source circuit protective devices. And if it's lights- check like how I told you, turn off one row, and then check the neutral again to see if it reads current now. Have a nice week coming up.


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## catsparky1

I like you're style mike . So many don't use eyes .


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## Incognito

CoolWill said:


> Not for handle ties, no. But why would anyone install MWBCs now? It is so stupid and inconvenient for multiple circuits to go down if one trips or needs to be services. So instead we install individual neutrals now. The number of neutrals has now tripled (for 3 phase) and more pipe is required.


So then for this code to be made by the manufacturers as you suggested, all these different manufacturers, (breaker, wire and conduit) would have had to all get together and lobby the code makers with their grand idea of making handle ties mandatory so they all can make more money? You seriously believe that?


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## CoolWill

Incognito said:


> So then for this code to be made by the manufacturers as you suggested, all these different manufacturers, (breaker, wire and conduit) would have had to all get together and lobby the code makers with their grand idea of making handle ties mandatory so they all can make more money? You seriously believe that?


They don't have to lobby. They are literally on the code making committees. They know the deal. You don't come out and say "We are should change the code to increase profits." All you need to,do is suggest a seemingly innocuous change, and they all recognize the potential for profit. "Kittens are dying due to MWBCs." 

I can't seriously believe you're so naive as to think mega corporations don't push unnecessary codes to make money. They exist ONLY to make money. Why sell one roll of white wire when you could sell three?


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## Incognito

CoolWill said:


> I can't seriously believe you're so naive as to think mega corporations don't push unnecessary codes to make money. They exist ONLY to make money. Why sell one roll of white wire when you could sell three?


Why would you get the idea that I think that way? I can’t seriously believe that you think ALL codes are made that way. 

Here is what I said in the other thread. 


I agree that some codes are made for the wrong reasons and manufacturers play a major role, but not all codes are made that way. Seems many jump on that bandwagon anytime they disagree with a code.


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## HackWork

Incognito said:


> So then for this code to be made by the manufacturers as you suggested, all these different manufacturers, (breaker, wire and conduit) would have had to all get together and lobby the code makers with their grand idea of making handle ties mandatory so they all can make more money? You seriously believe that?


 If you don’t believe the large corporations lobby to have laws put into effect that benefit their profit, then I really don’t know what more to say to you. As mentioned, in the electrical industry the manufacturers actually sit on the CMP- Code Making Panel.


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## Incognito

HackWork said:


> If you don’t believe the large corporations lobby to have laws put into effect that benefit their profit, then I really don’t know what more to say to you. As mentioned, in the electrical industry the manufacturers actually sit on the CMP- Code Making Panel.


Where did I say I don’t believe that? ??? Do you guys even read before posting? I said many guys blame the manufacturers anytime they disagree with a code. 

Here, I will quote what I said again and put it in red for those that missed it the first two times. 


I agree that some codes are made for the wrong reasons and manufacturers play a major role, but not all codes are made that way. Seems many jump on that bandwagon anytime they disagree with a code.


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## HackWork

Incognito said:


> Where did I say I don’t believe that? ???


 In the post that I replied to.


> Do you guys even read before posting? I said many guys blame the manufacturers anytime they disagree with a code.


 In my decade plus here, I have never seen that. People only blame the manufacturers when they are the ones to do it.

Other times we blame the idiots on the CMP for allowed design issues to be added. We often also blame the losers who send in dozens of proposals for stupid changes and restrictions, just so they can tell their loser friends that they did something in life.



> Here, I will quote what I said again and put it in red for those that missed it the first two times.
> 
> 
> I agree that some codes are made for the wrong reasons and manufacturers play a major role, but not all codes are made that way. Seems many jump on that bandwagon anytime they disagree with a code.


 That is not what I was responding to, I replied to the post you made in this thread.

This is getting silly. You are using hyperbole to say that other people are being hyperbolic.


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## gnuuser

the problem with a lot of commercial and industrial sites is they often have legal installations that cover many code cycles so you never know what you are getting into unless you research the wiring legends and change logs thoroughly (providing they actually do keep records)


its always the best assumption that a neutral will almost always be shared at some point, so you should treat everything as live until you prove it dead and even then you should isolate it!


We fired a few @$$hats who had a habit of just tagging onto the closest neutral to save wire (sharing a 3 phase neutral for a control circuit load) (a lot of equipment ended up damaged due to their $#itwork and a lot of downtime correcting it):vs_mad:


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