# 120/208 no neutral.



## zen

Today I was looking at a square d 200 amp 120/208 3 phase panel. It had 3 feeders and a no 6 ground coming in. There were only 2 loads in the panel. Each on 100 a breaker. Appears to feed ahu . I have not seen a panel set up this way..it appears they pulled no neutral because the didnt need to. Is this a common practice?

no matter what we theorize as electrics. It has always been .


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## wildleg

used to be ok. not sure if it is anymore tho.


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## erics37

If it's a 120/208 panel with no neutral then it's just called a 208 panel :laughing:

If your load doesn't require a neutral, then you don't need to install one. Same concept as, say, a standard household water heater. It's a 240 volt single-phase load, so we run two wires (plus a ground) to it and hook it up to a double-pole circuit breaker and supply 240 volts to it. It doesn't want or need a neutral so we don't give it one.

Many AHUs only require a 3-phase circuit to supply them. Many of them will have some taps from the incoming line into a control transformer and simply derive their own control circuit instead of having one supplied from the premises wiring system.

If you look at the nameplate of the equipment it will tell you what voltage requirements it has. If it says "208 3-phase" that is a different thing than "208/120 3-phase." The difference being the presence or lack of a neutral conductor.


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## erics37

wildleg said:


> used to be ok. not sure if it is anymore tho.


If your service is grounded then you are required to run the grounded conductor at least up to your service equipment because it is a fundamental part of your effective ground fault current path. 250.24(C)

Feeder circuits on the premises don't give a crap if you run a neutral with them or not.


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## Bad Electrician

wildleg said:


> used to be ok. not sure if it is anymore tho.


Done all the time for HVAC and VAV pnaels and MCC's and a slew of other single phase 208 and 3 phase 208 loads (and 480)


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## zen

Thanks for every reply. It makes sense that its there and why yet I kept saying as im looking at it, this should have been set up differently. My instincts tell me if the panel says 120/208 then it should have neutral accessories or been called a 208 x/wire panel. I believe there had been 120v circuits in it at some point because there were single pole breakers , loose "ground" kit screws and ko fillers in it. 

no matter what we theorize as electrics. It has always been .


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## Bad Electrician

zen said:


> Thanks for every reply. It makes sense that its there and why yet I kept saying as im looking at it, this should have been set up differently. My instincts tell me if the panel says 120/208 then it should have neutral accessories or been called a 208 x/wire panel. I believe there had been 120v circuits in it at some point because there were single pole breakers , loose "ground" kit screws and ko fillers in it.
> 
> no matter what we theorize as electrics. It has always been .


You can order a panel with or without a neutral, the namplates are typically the same.


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## wildleg

Bad Electrician said:


> Done all the time for HVAC and VAV pnaels and MCC's and a slew of other single phase 208 and 3 phase 208 loads (and 480)


well aware of that, I'm just not up on 2014 code. They seem to be requiring neutrals pulled in a lot of places that didn't used to be.


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## Bad Electrician

wildleg said:


> well aware of that, I'm just not up on 2014 code. They seem to be requiring neutrals pulled in a lot of places that didn't used to be.


Saw a panel about 400' from the main service 4-750 Kcmils, and one 277 VAC lighting circuit. Whole lot of copper and money for one 20 amp circuit.


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## RIVETER

zen said:


> Today I was looking at a square d 200 amp 120/208 3 phase panel. It had 3 feeders and a no 6 ground coming in. There were only 2 loads in the panel. Each on 100 a breaker. Appears to feed ahu . I have not seen a panel set up this way..it appears they pulled no neutral because the didnt need to. Is this a common practice?
> 
> no matter what we theorize as electrics. It has always been .


If your system only requires three phase operation or single phase 208, a neutral is not required. IF you did need a neutral then you would DERIVE it at your secondary of your service transformer. To DERIVE is to create what was not there. It is a difference of potential change for a lesser voltage such as 110, or 120 volts.
In deriving your neutral at the transformer and taking it to your panel you are making available the lesser voltage.


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## rockpanama

I would be more concerned about the lack of a grounding conductor.


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## Wirenuting

A 208/120 - 3 phase - 4 wire no neutral panel is the norm here for equipment feeds. We are all pipe here and drag the ground everywhere.
I love finding single pole breakers in them.


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## Dennis Alwon

rockpanama said:


> I would be more concerned about the lack of a grounding conductor.


It is probably run in emt so no equipment grounding conductor is required as the conduit is the equipment grounding conductor. Art 358.60


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## ponyboy

I'd say the majority of the 480 panels where I work are straight delta because all of our buss duct is straight delta no neutral. No special panels we just don't use the neutral bar


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## zen

Dennis Alwon said:


> It is probably run in emt so no equipment grounding conductor is required as the conduit is the equipment grounding conductor. Art 358.60


It is in emt and realistically I guess u could say with the pipe being the ground that the grounding conductor which is bonded to neutral in the panel before ir that the ground can be the neutral although undersized.

no matter what we theorize as electrics. It has always been .


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## Bad Electrician

zen said:


> It is in emt and realistically I guess u could say with the pipe being the ground that the grounding conductor *which is bonded to neutral in the panel before ir that the ground can be the neutral although undersized*.
> 
> no matter what we theorize as electrics. It has always been .


NOOOOOOOOOOOOO

Not at all, not under any conditions NO, NO, NO.

Once you leave the point of the neutral to ground bond, a neutral/GROUNDED CONDUCTOR and an Equipment Grounding Conductor (EGC) are treated as two seperate conductors.


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## RIVETER

rockpanama said:


> i would be more concerned about the lack of a grounding conductor.


Why!!!


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## AllWIRES

You always need a grounding conductor to bond the system. A grounded conductor is not required in all systems. 

250.24 applies only if the system is a grounded system. If its 120/208 then yes. Ive never heard of an unground wye system, 208?


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## RIVETER

AllWIRES said:


> You always need a grounding conductor to bond the system. A grounded conductor is not required in all systems.
> 
> 250.24 applies only if the system is a grounded system. If its 120/208 then yes. Ive never heard of an unground wye system, 208?


With the quick response I have to assume that you are referring to my post...if not, correct me. Grounding ...and bonding are two different animals. Do you agree or disagree?


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## TQuade

It would not be called an ungrounded wye system it would just be called delta. The term wye is used to identify a neutral is present. Both terms are used when installing transformers you have a wye transformer that you feed with what ever your using as primary conductors 3phase 480v for example and the secondary produces 3phase 120/208. A delta does not produce a neutral. In this threads situation panels used for ac loads and heating loads are very common not to have a grounded conductor due to only 3 phase loads and cost effectiveness not to pull a neutral wire your not planning on using.


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## RIVETER

TQuade said:


> It would not be called an ungrounded wye system it would just be called delta. The term wye is used to identify a neutral is present. Both terms are used when installing transformers you have a wye transformer that you feed with what ever your using as primary conductors 3phase 480v for example and the secondary produces 3phase 120/208. A delta does not produce a neutral. In this threads situation panels used for ac loads and heating loads are very common not to have a grounded conductor due to only 3 phase loads and cost effectiveness not to pull a neutral wire your not planning on using.


I don't necessarily agree with what you said. If you had a wye connected system...and only three phase loads, AND equipment that can run on wye type systems why would it not work. All electrical equipment works on a difference of potential. If the proper voltage is applied it should work fine. A neutral is not necessary and, to my knowledge does not necessarily indicate that it is a WYE system. Enlighten me.:thumbsup:


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## TQuade

You can only have a neutral on a wye system


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## TQuade

Their is a delta on the left and a wye on the right notice tap from the center of the wye that is your neutral connection


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## btharmy

TQuade said:


> It would not be called an ungrounded wye system it would just be called delta. The term wye is used to identify a neutral is present. Both terms are used when installing transformers you have a wye transformer that you feed with what ever your using as primary conductors 3phase 480v for example and the secondary produces 3phase 120/208. A delta does not produce a neutral. In this threads situation panels used for ac loads and heating loads are very common not to have a grounded conductor due to only 3 phase loads and cost effectiveness not to pull a neutral wire your not planning on using.


The wye of a 208v system consists of 3 phases. Whether you choose to bond XO to derive a neutral is optional. It doesn't "produce" a neutral. It can be a 3 phase 208v wye with no neutral.


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## TQuade

Why buy a transformer that produces a neutral and not use it.


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## RIVETER

TQuade said:


> You can only have a neutral on a wye system


So you are saying that you can't have a wye without a neutral???


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## TQuade

Sorry not "produce" I am incorrect on that term the neutral in a transformer is a point in the windings that has an equal potential with reference to the hot sides


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## RIVETER

TQuade said:


> Why buy a transformer that produces a neutral and not use it.


Transformers do not PRODUCE a neutral , necessarily:no:.


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## TQuade

No I'm saying if your going to have panels that are all 3 phase ac or heating loads why buy a transformer that is a wye set up i would provide a delta 480/208


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## TQuade

RIVETER said:


> Transformers do not PRODUCE a neutral , necessarily:no:.


 Sorry not "produce" I am incorrect on that term the neutral in a transformer is a point in the windings that has an equal potential with reference to the hot sides


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## RIVETER

TQuade said:


> No I'm saying if your going to have panels that are all 3 phase ac or heating loads why buy a transformer that is a wye set up i would provide a delta 480/208


I have never bought a large transformer. Do they charge extra for an XO?


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## Meadow

TQuade said:


> You can only have a neutral on a wye system


Then why do they make zig-zags? And what is a 4 wire delta secondary?


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## RIVETER

meadow said:


> Then why do they make zig-zags? And what is a 4 wire delta secondary?


WOW...COOL...That is a term that I have not heard for awhile. Do you understand ZIG ZAGS? They are useful in services.


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## TQuade

Yea I'm kinda lost on that one


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## TQuade

meadow said:


> Then why do they make zig-zags? And what is a 4 wire delta secondary?


A 4 wire delta is when one of the windings has a center tap and you pull a grounded conductor off of it


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## TQuade

It allows you for instance on a 480v 4 wire delta to have the ability to have 240v taps


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## RIVETER

TQuade said:


> Yea I'm kinda lost on that one


If you are referring to my post I am talking about ZIG ZAG auto transformers.


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## Meadow

RIVETER said:


> WOW...COOL...That is a term that I have not heard for awhile. Do you understand ZIG ZAGS? They are useful in services.


They are used when no neutral is present to create on artificially. A delta secondary is one example and a symmetrical point is needed. 




TQuade said:


> A 4 wire delta is when one of the windings has a center tap and you pull a grounded conductor off of it


Yes, which is called a neutral as it is common and symmetrical to 2 hots.


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## RIVETER

meadow said:


> They are used when no neutral is present to create on artificially. A delta secondary is one example and a symmetrical point is needed.
> 
> 
> 
> 
> Yes, which is called a neutral as it is common and symmetrical to 2 hots.


But do you know what a difference they can make in ground fault detection?


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## TQuade

Either way the transformer has to be set up to have that ability


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## RIVETER

TQuade said:


> Either way the transformer has to be set up to have that ability


In your opinion...or knowledge, what criteria does it take for a conductor to be called a neutral?


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## AllWIRES

RIVETER said:


> With the quick response I have to assume that you are referring to my post...if not, correct me. Grounding ...and bonding are two different animals. Do you agree or disagree?


I've been busy and only giving the site half a mind lately. I was referring to a post about the article I referenced I believe. 

Yes, grounding and bonding are two different animals. But every system requires bonding and grounding. But not true for being grounded. All three of which are different.


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## AllWIRES

RIVETER said:


> In your opinion...or knowledge, what criteria does it take for a conductor to be called a neutral?


I guess I haven't crossed paths with you yet riveter but you seem to be very confrontational with a touch of arrogance.

I may be wrong, as I haven't only read but a few posts and no entire threads in a few days.


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## Meadow

RIVETER said:


> But do you know what a difference they can make in ground fault detection?


Depends on how they are grounded. A solid bond automatically trips a breaker under a ground fault. A resistor can give you a high impedance earthed system, and an amp ct around it excess current means ground fault. 




TQuade said:


> Either way the transformer has to be set up to have that ability


Huh? :001_huh:


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## Meadow

AllWIRES said:


> I've been busy and only giving the site half a mind lately. I was referring to a post about the article I referenced I believe.
> 
> Yes, grounding and bonding are two different animals. But every system requires bonding and grounding. But not true for being grounded. All three of which are different.


:laughing: I don't blame you :laughing:


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## RIVETER

AllWIRES said:


> I guess I haven't crossed paths with you yet riveter but you seem to be very confrontational with a touch of arrogance.
> 
> I may be wrong, as I haven't only read but a few posts and no entire threads in a few days.


So what is your answer?


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## AllWIRES

RIVETER said:


> So what is your answer?


Answer to what?


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## RIVETER

AllWIRES said:


> Answer to what?


My assumption was that you were responding to post #41 of this thread. If that is the case, what is your answer?


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## AllWIRES

Article 100

Neutral Conductor. 
-The conductor connected to the neutral point of a system that is intended to carry current under normal conditions. 

Neutral Point. 
-The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system. 

-FPN: At the neutral point of the system, the vectorial sum of the nominal voltages from all other phases within the system that utilize the neutral, with respect to the neutral point, is zero potential. 

As usual the code says it best.


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## AllWIRES

I can't count. 

Can't you just ask a question? If you're going to confront me then do it.


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## RIVETER

AllWIRES said:


> Article 100
> 
> Neutral Conductor.
> -The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.
> 
> Neutral Point.
> -The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system.
> 
> -FPN: At the neutral point of the system, the vectorial sum of the nominal voltages from all other phases within the system that utilize the neutral, with respect to the neutral point, is zero potential.
> 
> As usual the code says it best.


I love it when some use the words of the code book to explain things. Can you tell me what all of that means?


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## AllWIRES

250.4 General Requirements for Grounding and Bonding. 

The following general requirements identify what grounding and bonding of electrical systems are required to accomplish. The prescriptive methods contained in Article 250 shall be followed to comply with the performance requirements of this section. 

(A) Grounded Systems. 

(1) Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation. 

FPN: An important consideration for limiting the imposed voltage is the routing of bonding and grounding conductors so that they are not any longer than necessary to complete the connection without disturbing the permanent parts of the installation and so that unnecessary bends and loops are avoided. 

(2) Grounding of Electrical Equipment. Normally non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials. 

(3) Bonding of Electrical Equipment. Normally non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. 

(4) Bonding of Electrically Conductive Materials and Other Equipment. Normally non–current-carrying electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. 

(5) Effective Ground-Fault Current Path. Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path. 

(B) Ungrounded Systems. 

(1) Grounding Electrical Equipment. Non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth in a manner that will limit the voltage imposed by lightning or unintentional contact with higher-voltage lines and limit the voltage to ground on these materials. 

(2) Bonding of Electrical Equipment. Non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the supply system grounded equipment in a manner that creates a low-impedance path for ground-fault current that is capable of carrying the maximum fault current likely to be imposed on it. 

(3) Bonding of Electrically Conductive Materials and Other Equipment. Electrically conductive materials that are likely to become energized shall be connected together and to the supply system grounded equipment in a manner that creates a low-impedance path for ground-fault current that is capable of carrying the maximum fault current likely to be imposed on it. 

(4) Path for Fault Current. Electrical equipment, wiring, and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit from any point on the wiring system to the electrical supply source to facilitate the operation of overcurrent devices should a second ground fault from a different phase occur on the wiring system. The earth shall not be considered as an effective fault-current path.


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## Meadow

RIVETER said:


> I love it when some use the words of the code book to explain things. Can you tell me what all of that means?


Why don't you, we aint as bright as you.


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## AllWIRES

RIVETER said:


> I love it when some use the words of the code book to explain things. Can you tell me what all of that means?


I've already proven my experience to my jurisdiction. I don't need to play swords with you. 

The code is what every professional should be referring to. Why would I put it in my own words when the law of the land has already worded it.


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## AllWIRES

Note: I would have just referenced the code sections but people are too lazy to look anything up. So, I have mentioned before i will be including all code text in my code references from now on.


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## RIVETER

meadow said:


> Why don't you, we aint as bright as you.


I take my knowledge of the craft very seriously as you probably do. I am not trying to be so "BRIGHT". I do want the correct information to be there.


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## RIVETER

AllWIRES said:


> I've already proven my experience to my jurisdiction. I don't need to play swords with you.
> 
> The code is what every professional should be referring to. Why would I put it in my own words when the law of the land has already worded it.


The "Supposedly" law of the land is the bare minimum that is required. If that is all that you require to operate...so be it.


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## AllWIRES

RIVETER said:


> I take my knowledge of the craft very seriously as you probably do. I am not trying to be so "BRIGHT". I do want the correct information to be there.


Then why would question a licensed professionals code reference as if a personal interpretation would be more relevant?


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## AllWIRES

RIVETER said:


> The "Supposedly" law of the land is the bare minimum that is required. If that is all that you require to operate...so be it.


:laughing: 

Nice...


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## RIVETER

AllWIRES said:


> :laughing:
> 
> Nice...


I expected that. You are not hurting my feelings.


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## AllWIRES

Go Back to the Future McFly.

I joined this thread on a code reference...


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## RIVETER

AllWIRES said:


> Go Back to the Future McFly.
> 
> I joined this thread on a code reference...


Wow...cool


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## zen

So were walking a job today and we wanna look in the panel. About 10 empty offices. So we kill the disconnect feedeing the panel. Open it up. Got spare breakers couple ahu s , condenser. Grounded and grounding are isolated. I see ahu has 2 no 6 and 1 no 8 green and landed on the grounding bus. I say to the ac guy " just air handlers , no heat?" He goes to look and says they have electric heat and green 8 was the neutral.. what are all the reasons this is wrong. I know it not safe. If the ground was lifted. Im sure its gotta have more concerns than that


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## zen

The pipe was used as the egc so if somthing were to cause bond seperation between the panel and the disconnect ground and neutral then the pipe becomes a back fed conductor. . Possible but how likely if disconnect is properly bonded to the panel.with running a ground and a neutral cause its "better" and superbonding the way it is to day. It seems like n/g are could end up in parallel paths even accidentally


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