MULTIGROUNDED NEUTRAL DISTRIBUTION SYSTEM

[mtnelect]

The multigrounded neutral system is the predominant electrical distribution system used in the United States. It permits an uncontrolled amount of electric current to flow over the earth unrestrained, posing the potential of harm to the public and to animals causing electric shocks and is presumed responsible for undetected electrocutions. To compound the problem of uncontrolled current over the earth, utility practices places harmful current from lightning strokes directly into customers homes.

 

[electrofelon]

Again? Hasn't this been covered ad nauseam already??

 

[mtnelect]

Again? Hasn't this been covered ad nauseam already??

This is the only formal study on this subject I have found. Show me another formal study that supports your opinion.

 

[mtnelect]

The multigrounded neutral system is the predominant electrical distribution system used in the United States. It permits an uncontrolled amount of electric current to flow over the earth unrestrained, posing the potential of harm to the public and to animals causing electric shocks and is presumed responsible for undetected electrocutions. To compound the problem of uncontrolled current over the earth, utility practices places harmful current from lightning strokes directly into customers homes.

Section 250-6(b) and (c), NEC – 1999, also states: “(b) Alterations to Stop Objectionable Current. If the use of multiple grounding connections results in an objectionable flow of current, one or more of the following alterations shall be permitted to be made, provided that the requirements of Section 250-2(d) are met. “Discontinue one or more but not all of such grounding connections. “Change the locations of the grounding connections. “Interrupt the continuity of the conductor or conductive path interconnecting the grounding connections. “Take other suitable remedial action satisfactory to the authority having jurisdiction. (c) Temporary Currents Not Classified as Objectionable Currents. Temporary currents resulting from accidental conditions, such as ground-fault currents, that occur only while the grounding conductors are performing their intended protective functions shall not be classified as objectionable current for the purposes specified in (a) and (b).”

 

[Hv&Lv]

The multigrounded neutral system is the predominant electrical distribution system used in the United States. It permits an uncontrolled amount of electric current to flow over the earth unrestrained, posing the potential of harm to the public and to animals causing electric shocks and is presumed responsible for undetected electrocutions. To compound the problem of uncontrolled current over the earth, utility practices places harmful current from lightning strokes directly into customers homes.

Got a better way to skin this cat??
you suggest SWER?

 

[mtnelect]

The currents that are continuously flowing currents over the earth, are objectionable. On the other hand, Non objectionable currents are those that flow over the earth momentarily until a protective device such as a fuse, circuit breaker or recloser operates to stop the current flow

 

[mtnelect]

Got a better way to skin this cat??
you suggest SWER?

For starters:
1) Disconnect the un-insulated guy wire from the Neutral at the service head and pole transformer and repurpose it as a "Guy" wire.
2) Install a separate insulated Neutral wire from the pole transformer to the service head.

 

[ActionDave]

Since the OP is so enthusiastic about the continual bludgeoning of his favourite equine that is no longer in possession of a heartbeat or measurable brain activity I'll reintroduce my idea that we make all the circuits in new construction line to line. Nothing else needs to change and all the current on the neutral just fades away over time.

 

[mtnelect]

Since the OP is so enthusiastic about the continual bludgeoning of his favourite equine that is no longer in possession of a heartbeat or measurable brain activity I'll reintroduce my idea that we make all the circuits in new construction line to line. Nothing else needs to change and all the current on the neutral just fades away over time.

Requiem for Multi Grounding Theory: I will not mention this subject anymore ! Unless asked.

 

[ActionDave]

For starters:
1) Disconnect the un-insulated guy wire from the Neutral at the service head and pole transformer and repurpose it as a "Guy" wire.
2) Install a separate insulated Neutral wire from the pole transformer to the service head.

Where does all that current on the newly insulated neutral wire go? Won't that all metal guy wire need to be bonded to something so that it won't stay energized in case of a fault? Seems like all you have done is added a wire and patted yourself on the back.

 

[Fred B]

Where does all that current on the newly insulated neutral wire go? Won't that all metal guy wire need to be bonded to something so that it won't stay energized in case of a fault? Seems like all you have done is added a wire and patted yourself on the back.

OSHA 30 training had a case study of a telecom lineman worker who in spite of working with appropriate PPE for the zone on the pole he was in, he was electrocuted. The guide wire had become energized below the insulator and he made hand contact with the energized guide wire. The Guide wire was not bonded and thus could not trip the fused disconnect. It was estimated that he was aware of being electrocuted for at least 15 seconds. Body found still on the pole by a line crew looking for the cause of the ensuing outage, that he had actually created when he made contact and then bonded thru him and the telecom grounding.

 

[mtnelect]

OSHA 30 training had a case study of a telecom lineman worker who in spite of working with appropriate PPE for the zone on the pole he was in, he was electrocuted. The guide wire had become energized below the insulator and he made hand contact with the energized guide wire. The Guide wire was not bonded and thus could not trip the fused disconnect. It was estimated that he was aware of being electrocuted for at least 15 seconds. Body found still on the pole by a line crew looking for the cause of the ensuing outage, that he had actually created when he made contact and then bonded thru him and the telecom grounding.

Every pole transformer is grounded at the pole and every service head is grounded at the service.

 

[tortuga]

@mtnelect I suggest you might be interested in how learning about MV distribution is done and has been done in the past, its an interesting subject lots of folks on here know tons about.

First Lots of ungrounded distribution still exists out there, there are issues with it also.
Alternative systems that you might like include:

• Compensated Distribution System (Petersen coils) are a interesting system.
• At a local gravel mine here they use resistance grounded another interesting topic.
• Another very very common form of multi grounded distribution is Line to Line connected transformers on the primary side. In this arrangement there is not any parallel primary current path.

Here is some reading for you:

Electrical Grounding Using the Isolated (or Ungrounded) Method - Technical Articles

Learn about the isolated or ungrounded method of system grounding, its main characteristics, advantages, disadvantages, and areas of application.

eepower.com

https://search.abb.com/library/Download.aspx?DocumentID=1MRS757370

https://selinc.com/api/download/2604

 

[mtnelect]

@mtnelect I suggest you might be interested in how learning about MV distribution is done and has been done in the past, its an interesting subject lots of folks on here know tons about.

First Lots of ungrounded distribution still exists out there, there are issues with it also.
Alternative systems that you might like include:

• Compensated Distribution System (Petersen coils) are a interesting system.
• At a local gravel mine here they use resistance grounded another interesting topic.
• Another very very common form of multi grounded distribution is Line to Line connected transformers on the primary side. In this arrangement there is not any parallel primary current path.

Here is some reading for you:

Electrical Grounding Using the Isolated (or Ungrounded) Method - Technical Articles

Learn about the isolated or ungrounded method of system grounding, its main characteristics, advantages, disadvantages, and areas of application.

eepower.com

https://search.abb.com/library/Download.aspx?DocumentID=1MRS757370

https://selinc.com/api/download/2604

Thank you ...

 

[Birken Vogt]

Since the OP is so enthusiastic about the continual bludgeoning of his favourite equine that is no longer in possession of a heartbeat or measurable brain activity I'll reintroduce my idea that we make all the circuits in new construction line to line. Nothing else needs to change and all the current on the neutral just fades away over time.

It seems to me that PG&E sometimes actively converts TO this type of system. They have mostly 12 kv delta primary out there with no neutral, but it was told to me that new builds are going to be 21 kv wye so as to lower current. But this means that previously 12 kv L-L existing single phase side lines are converted to a L-N tap off the 21 kv main line so all the transformers do not need to be changed out.

The funny thing is they do, very occasionally, run L-L 21 kv single phase side lines off 21 kv wye systems, but no rhyme or reason that I can tell.

 

[zbang]

no rhyme or reason that I can tell.

That seems to be the case too often with PG&E.

 

[Birken Vogt]

That seems to be the case too often with PG&E.

Well it is funny when you look at their primary distribution system, the way it is built, they seem to follow some major rules and procedures to the tee no matter what and have done it very cleanly for decades. Not like some of the more shoddy city or rural utilities I have noticed. But I am just some guy who looks at wires, I don't know everything.

 

[LarryFine]

Since the OP is so enthusiastic about the continual bludgeoning of his favourite equine that is no longer in possession of a heartbeat or measurable brain activity . . .

 

[mtnelect]

Thank you for that, that is hilarious !

 

[Birken Vogt]

The bottom line is, PG&E runs 80% of this state, power wise. They set the tone.

Most of their old stuff is delta but it has been declared by them that any new systems will be MGN 21 kV

All of the surrounding pocos to the north and east already run MGN by default, Pacificorp and NV Energy

They have been building MGN 21 kV systems since the 1960s and they are not going to stop now just because you said so.

They have been sued and lost a dozen times, high profile, going back decades, and they just keep going the same as ever.