Odd electrical problem

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So the ice storm the othe day took down many trees in our area. My BIL called me because a branch fell and knocked his neutral wire loose from the weatherhead. Some things worked others didn't, biggest problem was when the fridge kicked on the whole house went dim.
I asked him about a ground rod and he was sure he didn't have one. Until he could get a guy to climb up there I told him to go get a ground rod at the Borg and pound it in as far as he could and connect it to the ground/neutral bar in his panel. He was able to get the ground rod about 5' down with a hammer and connected two 12ga copper wires from the rod to his panel. After he did this there was no improvement at all.
An hour later an electrician he knows showed up and reconnected the neutral to the weaterhead and all was better. Neither of his hot leads at the weatherhead were loose or needed to be touched. So why wouldn't going directly to ground from the panel have helped his problem?
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Limp Arbor wrote:

'Cuz the neutral bus that was disconnected was/is isolated.
--
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He may not have a seperate ground rod, but I'll bet that his panel does have a grounding conductor that connects to earth ground through another means, typically an underground cold water pipe. And if it doesn't, that needs to be fixed ASAP.

Because:
A - It was likely grounded to begin with
B - The ground isn't designed for or capable of providing the same high current capacity back to the transformer that the service neutral conductor can handle.

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snipped-for-privacy@optonline.net wrote:

The purpose of attaching a ground wire to a water pipe is not to provide a ground for the electrical service, it is to provide a ground for the plumbing system.
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HeyBub wrote:

The same nonsense that was in a thread about a month ago.
The NEC has, since the beginning of time, required a metal water service pipe (10 ft in the ground) to be used as an earthing electrode. It still has that requirement.
If the water service pipe is plastic (which yours may be) then different rules and different methods apply and metal interior pipes must be bonded.
Your statement, as a general rule, is simply false. Just like it was a month ago.
--
bud--



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On 2/3/2011 9:53 AM, HeyBub wrote:

Depends.
In the town i have rentals in, they ONLY require the copper pipe coming in the house to be the ground. Any additional rods or bonding is optional. They also REQUIRE ALL replacement water service entrance pipes to be copper
--
Steve Barker
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Steve Barker wrote:

The way I heard it, bonding to a water pipe protects you from a floating neutral as you are skinning muskrats in the sink. As you prepare to process the muskrat guts in the disposal, while holding a poorly-insulated electric carving knife, you reach up and touch the metal faucet...
Contrary to popular thinking, muskrat entrails are an excellent conductor, as proved by real science.
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Limp Arbor wrote:

As an earthing electrode ground rods suck. A very good resistance to earth would be 10 ohms. If you connect a hot wire to the rod you get a current of 12A.
In this case the rod is 5 ft instead of 8 feet. But much worse - it is in frozen ground. Frozen ground has a much higher resistance than non-frozen ground.
I would not expect a ground rod to be very effective for an open neutral in the best case. This was not the best case.
The reason the earthing system might work at all is the N-G bond required in US services. The earthing system is not intended to be a substitute neutral.
If the electrode is a water pipe (which is required to be an earthing electrode if there is 10 ft of metal in the earth), and you have a metal municipal water system, you can have the neutral current through the earthing connection to the water service, through the metal water supply lines to adjacent houses, to the services for those houses, and back to the utility through the service neutrals in those houses.
You might want to find out how the system is earthed.
--
bud--

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As far as supplying electricity to a house a ground rod has no useful purpose other than saftey. Having one will not replace a broken neutral, not having one will not effect how well the electrical distribution in your house functions.
Jimmie
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*As someone else said the ground rod is not a substitute for a neutral. Neutral current wants to return to the power company transformer. To get there it normally travels over the neutral (Grounded conductor) wire. When the neutral wire is broken, but is bonded to the grounding conductor in the main panel, the neutral current will attempt to get to the transformer via the grounding conductor. However whether it makes it back to the transformer or not depends on the conditions. The transformer must have an unbroken grounding conductor connected to a ground rod in order for the neutral current to travel through the earth. There should also be a path of low resistance and that would depend on the soil conditions and distance.
I have heard stories from other contractors and inspectors of the neutral current from one house traveling through the earth to a neighbor's grounding conductor and going back to the transformer via the neighbor's neutral wire.
I hope that your BIL turned off the main breaker when he attempted to connect the ground rod. All of the return current could have been on that grounding conductor.
BTW the advice that you gave your BIL could have been fatal not only to him, but to someone who just happened to be walking on his lawn at that time. Also, If there was a pool nearby, although not likely this time of year someone in the pool could have gotten zapped from the stray current in the earth looking for a path to the transformer. He could also have damaged some appliances by having a higher voltage than normal passing through them The best advice in this case would have been to shut off the main breaker and get the neutral wire reconnected.
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Yes, he turned off the main and all of the individual breakers before trying this. Turned the main back on then each breaker.

How could someone walking by have been shocked? Doesn't electricity always seek ground?
BTW he also got the same advice from another guy who works at the power company. Obviously not as a permanent fix but to get his heat working til he could get the neutral wire reconnected.
So in my house as with most houses even though all of the neutrals and grounds are tied together in the panel everything is going back to the transformer?
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The unbalanced portion of the 240V service current wants to go back to the transformer via the neutral wire. If the service neutral is unhooked, it will attempt to go back via the ground connection and the earth. But exactly what path it takes is not determined. It depends on the resistance of the earth between the two point, and it's not going to be a beeline. If a swimming pool happens to bein that path, you could have parts of the pool energized, at least to some extent. Would it be likely to kill someone, probably not, but who knows?

I hope so. That's the only way to complete the circuit.
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On Feb 3, 2:45pm, snipped-for-privacy@optonline.net wrote:

So I guess that is why you can't buy a "Worm Getter" anymore...
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Limp Arbor wrote:
...

Some sections of the world where ground has a decent conductivity owing to mineral concentrations have actually used single-wire distribution in rural areas for cost-saving purposes where there is no return neutral; all is ground. (Some areas of Canada did; haven't been up there in 20+ years so not sure if all is yet gone or not...)
--
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DEFINITELY all gone. Canadian electrical distribution safety requirements today are (generally) higher than those in the USA.
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snipped-for-privacy@snyder.on.ca wrote:

It would be difficult for them not to be. The NESC that US distribution is based on is pretty much all "it should be done this way unless you don't want to for some reason, in which case do whatever you want".
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snipped-for-privacy@snyder.on.ca wrote: ...

Possible altho where I knew of them last were in the extremely rural areas on (I think) the equivalent of US REC (Rural Electric Co-operatives) lines. The cost of those for the low load/mile ratio is quite high so it wouldn't surprise if there were still at least some extant...
--
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dpb wrote:

I suspect single wire earth return was common in the US in the early days of electrification of farms under the REA. About the time the REA was created in1935 under 15% of farms had electric utility power. In the early 1950s almost all did. From comments by a utility engineer in Canada it sounds like early Canadian rural electrification was earth return, with a return wire becoming common in the mid 1950s. Likely the same in the US. As you said, low density makes electrification of farms expensive.
The resistance of through the earth in flatland is probably quite low. Making a low resistance connection to the earth is not real easy. But the connection was low current. If you actually had a 100A 240V load and the distribution was 7200V the primary current is only about 3.5A. Early farm loads were nowhere near 100A.
--
bud--

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I believe they were all replaced about 10 years ago after sme "stray voltage" scares where cattle were dying.
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On 2/4/2011 6:26 PM, snipped-for-privacy@snyder.on.ca wrote:

I've called the local power company a number of times to report that metal termites (the bipedal variety) have cut all the copper ground wires off the power poles for miles in certain neighborhoods around here even downtown areas. The wire is cut off as high up the pole as a human can reach. I know those wires and ground rods aren't part of the power circuit but are more than likely part of a spark gap unit to send lighting to ground. I suppose the power company will have to switch to galvanized steel ground wire. Those vermin are responsible for a lot of the lightning damage around where I had a warehouse years ago, they would even come over the fence after small amounts of wire. I wonder, I've seen human sized insects on TV insurance commercials.
TDD
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