 DarkLogixTexan and ProudPremium
join:2008-10-23
Baytown, TX
kudos:3 | reply to MatrixHDV
Re: Myth of the Neutral Wire ok.
I know at my home its alu from the pole, underground and into the meterbox
Then currently cu from the meterbox to the main panel. |
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 John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | reply to MatrixHDV
said by MatrixHDV:As to why copper is commonly run from the weatherhead to the meter pan is something you would have to bounce off an electrician, my guess is they do it to avoid the additional work needed to prepare aluminum for termination.
Smaller conductors for the same ampacity meaning reduced conduit size for the mast. Prepping Al is no big deal for Sparky.
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No amount of force can control a free man, a man whose mind is free. You can't conquer a free man; the most you can do is kill him. Well, you can try to...
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 tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8
 ·G4 Communications
·Fairpoint Commun..
 ·Hollis Hosting
| reply to MatrixHDV
said by MatrixHDV:As to why copper is commonly run from the weatherhead to the meter pan is something you would have to bounce off an electrician,
I wonder if copper vs Aluminum service entrance conductors is a regional thing. Even 30 years ago when we built our house Aluminum service entrance conductors were the norm here in NH.
Interesting Mike Holt video, thanks for posting. I love learning the history of why things are the way they are. I'm old enough to remember those little MaBell trailers. Never occurred to me optimum ground rod length was scientifically determined by what would fit into the trailer.
The last bit where Mike was complaining even utilities did not fully understand the ramification of Neutral current was pretty unsettling. Everything is a trade off, safety is no exception. I don't have a problem with a cold hard calculation where X amount of $ saved may result in an x increase in electrocutions. But realizing utility engineers do not seem to understand the physics is very troubling.
I did a little quick digging. There were about 550 electrocution deaths in the US in 1993. According to NOISH of those 200 were work related. The electrocution death rate has been improving year over year.
»www.cdc.gov/niosh/docs/98-131/pd···-131.pdf
Any idea what the death and property damage rate is due to neutral faults? I assume it is greater then 0 but imagine it is a pretty small number.
/Tom |
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| said by tschmidt:Any idea what the death and property damage rate is due to neutral faults? I want to make some comments about (human) safety in relation to the scary scenario described earlier. The lowest impedance path to real ground may not to be through that long 5th conductor.
I also came across this thread ... some electricians do not understand/apply Ohm's law even when no inductance/capacitance is involved in the calculation.
»How to calculate the amperage of paralleled conductors??? |
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garys_2kPremium
join:2004-05-07
Farmington, MI | reply to sk1939
All this makes me want to install a 1:1 transformer right after my meter so I can isolate my neutral/ground from the poco's. |
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| said by garys_2k:All this makes me want to install a 1:1 transformer right after my meter so I can isolate my neutral/ground from the poco's. You will still need to ground the premises side at a safe distance from the utility side.  |
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4 edits | reply to lutful
said by lutful: The lowest impedance path to real ground may not to be through that long 5th conductor. I find it odd that you cannot understand, even with a diagram, the purpose of the "5th" conductor, that being a uni-grounded neutral which contributes greatly to safety and IS NOT a path to ground, but is in fact a return path not involving ground to the transmission/distribution transformer at the substation.
The purpose is quite simple and that is to provide the primary voltage an isolated path from the transformer back to the substation.
It's basic electricity 101 pure and simple.
As to the second part of your post, I would suggest you get a better understanding of how to connect two transformers to each other without endangering the public before criticizing an idea that actually worked and worked well.
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| said by MatrixHDV:said by lutful:I also came across this thread ... some electricians do not understand/apply Ohm's law even when no inductance/capacitance is involved in the calculation. Thats because it was not applicable in that application, which by the way worked as built without a hitch. Suppose the conductors were actually mismatched and it did not work. Your personal opinion that the simple calculation was not "applicable" would not have saved you from legal action.
Anyway, I only pointed that out only because you were crusading about unsafe practices in power distribution in a thread which started as a simple explanation of the role of the neutral conductor in a home or office setting. |
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1 edit | said by lutful:Anyway, I only pointed that out only because you were crusading about unsafe practices in power distribution I guess you don’t understand distributing primary voltages (7.2Kv) is a different world from running 120 volts to temporary lighting.
As for legal action you failed to notice I posted in the thread the production company’s insurer signed off on my idea. |
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 AVDRespice, Adspice, ProspicePremium
join:2003-02-06
Onion, NJ
kudos:1 | said by MatrixHDV:As for legal action you failed to notice I posted in the thread the production company’s insurer signed off on my idea.
meaning?
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
2 edits | reply to MatrixHDV
said by MatrixHDV:The purpose is quite simple and that is to provide the primary voltage an isolated path from the transformer back to the substation.
It's basic electricity 101 pure and simple. Your "current" understanding of "voltage" imply you flunked that course ... if you actually took it. 
Instead of a retort, sketch out a complete electrical circuit after the fault scenario you described, put in some realistic numbers for the impedances, and run a simulation.
*** This cable technician died because 880V was induced on a (disconnected) ground conductor from the nearest 2400V phase conductor. Scale that up to kilovolts ... there is no escape from high "voltage" when enough "current" can flow to ground through you. 
»ecmweb.com/shock-amp-electrocuti···und-wire |
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1 edit | said by lutful:Instead of a retort, sketch out a complete electrical circuit after the fault scenario you described. Already did a number of posts back but guess you missed that, it was also discussed in the Mike Holt video I posted a link to. |
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| reply to AVD
They take responsibility if something was to go south. I wanted to run cords to the location, but they shot down the idea due to the narrow gangways and insisted we find another way to get power below deck, which is how the idea of using the ships existing wiring was hatched. |
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 rchandraStargate Universe fanPremium
join:2000-11-09
14225-2105 | reply to harald
Furnace installation manuals will mention this, and several fix-it sites will point out checking the grounding if the furnace is not igniting, or only igniting for a short while. I don't have a reference for you, but I remember reading in the past month or so that those flames are sensed by electricity conducting from some element stuck in the flame to ground.
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English is a difficult enough language to interpret correctly when its rules are followed, let alone when a writer chooses not to follow those rules.
Jeopardy! replies and randomcaps REALLY suck! |
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| reply to tschmidt
said by tschmidt:The last bit where Mike was complaining even utilities did not fully understand the ramification of Neutral current was pretty unsettling. Everything is a trade off, safety is no exception. While the "5th wire" camp is filled with quite experienced linesmen and electricians, some of them do not actually understand how that extra conductor will become fatal during many different fault scenarios. |
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1 edit | said by lutful:While the "5th wire" camp is filled with quite experienced linesmen and electricians, some of them do not actually understand how that extra conductor will become fatal during many different fault scenarios. Then they are neither experenced nor worthy of the title of linemen...
The reason is from the first day they put on a yellow Journeymans hardhat it is drilled into them to treat all conductors bare or insulated as hot until proven otherwise and no work on de-energized conductors will be perfomed until all conductors and equipment are throughly bonded and grounded...
This diagram explains it all.
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| I suspect "Tank" in the diagrams is the case of the transformer. Right? Does term originate due to the case serving as a container for the transformer oil? |
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
·TekSavvy DSL
| reply to MatrixHDV
said by MatrixHDV:said by lutful:... do not actually understand how that extra conductor will become fatal during many different fault scenarios. This diagram explains it all. No. That diagram only reflects wishful thinking. The long run of the 5th wire has significant inductance and resistance. Significant current will flow into the ground near the pole and nearby premises.
Here is a diagram showing the problem you described originally and the ideal solution from IEEE/NESC. The utilities could skip one spark gap and the separate ground for primary ... but they MUST have multiple paths from neutral to local ground if they want to save lives. That is my final comment on this issue. |
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AVDRespice, Adspice, ProspicePremium
join:2003-02-06
Onion, NJ
kudos:1 | reply to MatrixHDV
said by MatrixHDV:They take responsibility e idea of using the ships existing wiring was hatched. I bet they didn't...
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* seek help if having trouble coping
--Standard disclaimers apply.-- |
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2 edits | reply to lutful
said by lutful:No. That diagram only reflects wishful thinking. No it's actually from an IEEE paper on MGN's.
The long run of the 5th wire has significant inductance and resistance.
Significant current will flow into the ground near the pole and nearby premises.
BTW in reference to your right hand diagram utilities don't use spark gaps for that purpose they use neutral isolators, spark gaps haven't been used for that purpose since the 50's.
And since your diagram is of a 5 wire circuit you have confirmed what I have been saying all along, with the exception of one little error, there should be no ground except at the substation on your primary neutral, grounding it at or near the pole will produce dangerous step voltages around the grounding electrode should the primary neutral go open.
That is my final comment on this issue. |
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