Such incidents happen quite often in undeveloped countries and everybody just gets used to it 🙂.
Apply a large unbalanced load. (Washing machine may be enough; room heater or toaster or Mr Coffee is sure enough.) Measure the 240/120 split without and with the load.
Time I smoked my amp, it was 190V on my side and 45V on the side with the luke-warm coffee maker.
Ya know, my neighbor up the street told me that very same thing the other day, as we were discussing my plumbing problem mention here previously.
She said it was due to a poor ground as well.
As to your only feeling the shock with water running, I suspect the pipes were made of PVC perhaps, being an insulator if no water was running.
Certainly, they're illegal. But they can be found in cheap web outlets or on the village market. I have had some in my hand that were like that. It's just as with the cheap phone chargers, they don't comply to the safety standards and are somtimes downright dangerous, but they are easy to come by anyway.
Non-compliant electrical goods are IMO an underestimated issue at the moment.
And include non-compliant specifications to that as well.
Advertised 'wattage' ratings, etc..... it's all about making something (by lying) impressive enough to help sales.
Brings to mind things like desperation, greed.
Eh bien, Putain de sa mère!! (as an old colleague would often say as he banged his head on the overhead compartment door coming into the train)
Zer eez a lot of "bad grounds" in ze country, yes?!
Seriously though, I did not expect these things could happen in a house. I mean, I am not sure I fully understand the interaction between the electrical and the water system, as I understand, bot are independant... But in any case, reading all of this is very entertaining, if not informative. Thank you to all who posted.
Buy an old engine block, at least 20 kilos or so, and bury it in a pit at least 6 feet deep, use a galvanized or stainless steel wire to connect.
Special 'grounding plates' and chemical earthing are alternates.
Two wires are better.
Cover 50-50 with wood charcoal and sea salt, and add a PVC pipe to replenish water / salt as needed.
Effective as ground.
Special 'grounding plates' and chemical earthing are alternates.
Two wires are better.
Cover 50-50 with wood charcoal and sea salt, and add a PVC pipe to replenish water / salt as needed.
Effective as ground.
Connections to Planet Earth are only there for safety during unusual events.
They have no impact on day-to-day AC power quality.
They have no impact on day-to-day AC power quality.
Not if you live in the middle of nowhere with a single conductor power system...
https://en.wikipedia.org/wiki/Single-wire_earth_return
https://en.wikipedia.org/wiki/Single-wire_earth_return
You mean New Jersey? We had a wonky ground after Super Storm Sandy and it blew out the SMPS on our fridge. The power company got to it pretty quickly! (The tree surgeon said the storm was sending his 3 kids to college!)
My sister in Ohio had the 160V/80V issue at her house after some serious remodeling -- when it went over 162 her oven shut down!
True, Planet Earth can be used as a path or conductor in some power systems.
But in the 120/240 Volt, US type power systems, the connections to Planet Earth are for safety only.
Not true. Rural USA and Canada commonly use single wire like in the article I linked.
But normally, the ground IS a safety device AKA power will still work without ground.
Electricity is the only trade you can do completely wrong and dangerously but it still appears to work fine. People notice a leaking pipe but not a high impedance connection 🙂
But normally, the ground IS a safety device AKA power will still work without ground.
Electricity is the only trade you can do completely wrong and dangerously but it still appears to work fine. People notice a leaking pipe but not a high impedance connection 🙂
Citation needed. The Wiki article mentions ONE <10 mile installation in bum-freeze Alaska. There is a link in one of the town-pages which no longer works. However this sure sounds like transmission, not delivery; house-people never touch this circuit, it is brought down for them to 240V CT and a permafrost rod. (HTH do they even get a power-efficient ground in that land??)
Lots of "invisible" bad plumbing. Even 60 years ago backflow was an issue. "Dont' drink from the hose!" Real problem as LA grew into the hills amid massive pressure differences and sudden drops. Also the hose in the laundry-sink tub. It has taken that long for "some" districts to "require" whole-house backflow valves. Which still does not protect you from your own blackwater.
This citation is specific to the distribution of power at utility voltage levels (in rural areas this varies between 5 kV and 12 kV phase/phase). Once you run to each end-user, the utility serves a power transformer, with a secondary voltage that is typically split 240V (aka center tap) single phase. The center tap is solidly grounded, and thereafter is properly termed "grounded conductor" by the NEC, although most refer to it as "neutral conductor".
This is very different than this thread's subject matter of open neutrals and poor grounding, ground rods, etc. The utility has many ways of bringing power to a customer. Sometimes it is via an ungrounded three wire system, a reactance or resistance grounded three wire system, a solidly grounded 4-wire system, or in rural cases, a single wire with earth/water as the return. Regardless of what the utility is doing, the end user gets a solidly grounded system* and it is split phase. I hesitate to say they "never" get a single wire system in the US, but I would confidently say 99.99% of the time#.
The reason this is tolerated is that under worst case conditions of poor earth-return system, it is the utility system that suffers, not the end user. Lightning arresters have to be rated for the utility system grounding type, for example. But as far as the end user can see, the worst they see would be a small undervoltage condition, but their grounding is strictly determined by the local equipotential grid established with the ground rod(s). The end user does not experience poor grounding, even though the utility system may under a single wire system.
Summary: single wire systems exist for US utility systems, but not for end users.
* Not talking three phase systems, where some customers actually request ungrounded systems. Trying to stick with our relevant subject matter.
# perhaps if you order a circuit that is dedicated for light poles, they might provide you with a single wire system. But never for residential environments.
OTOH, There are single wire 500kV+ DC power systems that also use Earth as return?
Single wire power is more common than to be ignored.
Single wire power is more common than to be ignored.
For me, a simple visual inspection from the sidewalk found the breaks.
The power company guy will have to use a clamp over meter to check the currents. If he clamps over the neutral and finds zero current, it most likely is a lost neutral. Clamping over all three will also show that current is going in, but not coming out, another sign.
Hopefully he will also have a Fluke 1630 earth ground clamp meter. This is clamped around the neutral, and when activated, reads the impedance of the grounding circuit (neutral). If the neutral is open anywhere, the meter will tell him that. It is capable of reading from 1Kohm to .025 ohms. It should read less than 25 ohms, that is the 8 foot grounding rod NEC maximum resistance.
My experience is that open neutrals from pole transformers are typically obvious at visual inspection from the street.
Others have correctly described what an MOV will do. If the neutral is lost, and the powerbar is on the other leg of the feed, it will see the overvoltage and blow up., throwing itself on the grenade.
It is possible that the washing machine used to have some kind of transient suppression across relay contacts that failed..but see below..
(really important stuff under this sentence....)
If he puts an incandescent light in the outlet where the powerbar was, and has someone else turn on the washing machine while he watches the light, and he sees it get brighter, that is a clear indication of a lost neutral.
If that occurs, it is EXTREMELY EXTREMELY, EXTREMELY dangerous...(did I mention extremely??). It may indicate that the plumbing ground is also degraded by corrosion, and there is very little between him and electrocution by an AC appliance and any plumbing in the apartment, like a shower, sink, dishwasher, heating radiator.. (This is the schtick he would have to use with the power company, and it is extremely effective. I used it in the village here, laid it on kinda thick, saying I was the NEC expert at a national lab, teach this stuff, yada yada yada... with no shame, and no remorse. The power company actually fixed it within 15 minutes of the call. I found out later that the business owner's husband was a plumber and has indeed experienced lost neutral near-electrocutions (personally) in his work and was so happy with my intervention.) So all said and done, my grand-daughter was very well treated when she visited the store (trinkets, the kinda stuff little kids love.)
The best part was that my geekiness actually paid off for once.. Once every 65 years...I'm on a roll..
John
While I agree with your safety statement, as a result of the earth grounding at every 2 or 3 poles (east coast), somewhere between 5 and 10% of the utility current is carried through the earth. A consequence of trying to protect us from lightning strikes. But leaving a gradient through most peoples property.
Which amplifies the need to prevent upside down houses, where cable/telephone are fed to the opposite side of the house from the power.
Also shows the need to NOT do any foolish earth grounding for an audio system anywhere other than at the service feed.
John
A some point in the undefined future, I am really must sit down with some 6HV5As and look at the plate curves with ~700V plate and positive grid bias. Since I don't have anything like Smoking Amp's nifty-doodle curve tracer, I'll need to do things the slow way and plot the results in Excel, including whatever grid current I observe.
Well no. The rule requires either:
1] The single ground rod measures less than 25 Ohm. But the requires an expensive meter and up to 25 minutes testing time.
2] or a second rod must be added.
So in residential situations, they just add a second rod and call it a day.
Even with two rods, reading of closer to 100 Ohms are common at some times of the year in most locations.