The other day we had a blackout in my house. My wife went down to the main circuit panel and the whole house circuit breaker was flipped. Loose and everything, and when she tried to flip it back, it didn’t go. Of further interest was that the whole panel was wet. There had been a major wind-and-rain storm here in NJ, and apparently water got in from outside.
We called an electrician who refused to come down himself but did tell us that it was dangerous to turn it back on because you could fry up all the wires and/or burn the house down and all sorts of other delightful consequences. But after a lot of paper towels and blow-drying (using a 100 foot extension cord connected to a neighbor’s line) we got the thing dry and gingerly turned it on and it worked, and we later got an electrician to come down and OK it (plus he sealed up the hole where the wires ran through).
In any event, what’s interesting is that several neighbors later said that they too had had a blackout at around the time that we did, but their power went back on by itself after about 15 minutes. But there’s no doubt that we had a legit water issue, what with the circuit breaker having flipped and all the water. But I would have to think these are related, and that somehow our issue triggered a blackout in the rest of the neighborhood as well, though theirs resolved itself on its own.
Is that correct, and if so, how exactly does that work?
In our neighborhood, we have a lot of aerially distributed electric wires running through some similarly aerially distributed trees. We get a lot of momentary interruptions due to falling branches.
This has caused me to learn that when the equipment detects a fault somewhere on the street, it automatically breaks the circuit for a few seconds, and powers it up to see if the fault is cleared. It will make 3 attempts before going hard down.
Intuitively, I would think that if you had a fault between your main house breaker and the street, the street equipment might see it similarly to a distribution fault and begin the auto-recovery cycle. In your case, being that your neighbors saw a 15 minute outage, maybe the auto-recovery process didn’t work and needed a technician to determine that it was safe to manually override.
Your main breaker will trip on a significant short from something in the house. Something that a single circuit could not handle. Water in the main panel could certainly do that. And since there is water inside the panel at that location it may very well short out the input side of the main breaker as well. That impacts the service itself and it should handle it like HMS_Irruncible suggests. It does take a serious short in most cases to trip the distribution. Witness the often seen wires laying on the ground sparking all over the place during storms.
The timing is a bit weird. As HMS noted, there are automatic devices called reclosers in the utility system. They work more or less in the reverse of circuit breakers - if a short circuit happens in the multi-thousand volt lines, the fault more often than not self-clears. Wind blew the wires together, an unfortunate squirrel stepped on a transformer, etc. - the wires only touched for a moment, and the squirrel went poof. Instead of tripping out completely, the recloser will wait a few seconds and attempt to restore power. If power stays on, great, if not, the device will try again. Usually they’re programmed to do three reclose attempts, and send a success or fail signal to the utility operations center.
But that all happens in seconds, not 15 minutes. My guess is a lineworker was nearby and able to restore power to the neighbors.
Years ago the northeast of the US has a major blackout. My dad was having work done at his house when a contractor cut into a power line in the wall and tripped the breaker, but it was at the time of that major blackout, and my dad has a view that many towns can be seen from where the contractor was cutting, and the contractor looked in horror seeing the communities in the distance lose power at that time.
One of the schools here (Thornbury High), had an army cadet core, dating back to WWI. When that became less popular, less politically correct, and of less interest to the army, they forced closure of some of the remaining high-school groups by requiring them to upgrade their equipment to military standard.
The parents at Thornbury High responded by building a military-grade arsenal, complete with dual-supply electricity. Many years later, when the school no longer had a cadet core, the building was used as a classroom.
And when one of the students shorted out the electricity, the supply, unfused back to the substation, took out the whole subsection.
So yes, if you’re living in an armoury, a fault can take out the neighborhood.
Not sure of what type of main panel you have. The power should come in the top to the main breaker, either direct wired or through buss bars. When the breaker trips and the power is still on the wires or buss bars are still electrified. You may have been in some danger in the panel with paper towels.
If the water caused a short in the panel there should have been signs of the electrical arc. But a flash over could cause the breaker to trip at the same time tripping the utility breaker, which should reset. If you breaker was tripped you can not just flip it back on. it needs to be reset 1st by pushing it to the off direction. Then turning it back on. And before working in the panel check to be sure there is no power, sometimes old brakers do not open properly.
I do not know what the electriction was talking about. He should have been willing to tell you how to reset the breaker safely.
turn off all the breakers in the panel. (close the main with no load.)
Push the handle of the tripped main breaker fully off to reset.
When closing the main breaker DO NOT STAND IN FRONT OF THE PANEL. Stand off to the side and close the breaker while looking away. If yo uget a flash over it can blind and burn you badly. You should have on long sleeve shirts not made of a fabric that can melt.
If the breaker holds when you reset the close the load breakers one at a time.
I had one night when I was sitting in m room when suddenly my window lit up. I was facing away from it, and could see my shadow on the wall. This was accompanied by a rather loud bang. Then my lights went out.
The transformer on the street had blown 2 houses away.
It was a few hours before power was restored, and while the power company was replacing the transformer, someone also cut down one of my neighbor’s trees that was growing up into the line that was going to their house.
I had noted that tree in the past, and wondered if it was going to be a problem.
It was a bit rainy and windy, and my assumption was that that tree somehow caused the transformer to blow, but I never followed up with anyone to be sure.
It’s not uncommon in rainy areas like say… Houston, for transformers to just blow due to heavy rainfall. I’m not at all familiar with the mechanism, but it’s not at all uncommon to see a flash, hear a bang and have your power go out (or see that it went out across the street) in heavy rainstorms.
I was out driving in a heavy rain one night. I was On Tully road in SanJose on the West side of the 101 highway. On the east side about 2 miles away a transformer of capicitor bank on a ppower pole blew. It light up the whole valley floor and then all the lights went out on the other side of the highway. It was a sight that I will nver forget.
Your story is very interesting to me, since I have a current close personal connection to Thornbury
What’s the timeline on that? I definitely need to give my youngest family some information on this so that he can appreciate his local area history and amaze his classmates.
Cadet corps aren’t totally dead in the State system by the way - Melbourne Girls’ College still has one, or something like (well, they did six years ago when I got my last information on the subject). Of course, that might be considered slightly less threatening, being a girls’ school.
I was walking from my bus stop to work one morning shortly after 9/11 when a transformer blew practically right over my head. Took me a while to work out what just happened.
A transformer reduces the voltage from the grid (around 7.5 kV, I believe) to 120 V / 240 V split phase. I have read that there’s a 3 A fuse on the primary side of the transformer.
There are three terminals on the secondary of the transformer, and these can be connected to one or more homes. I am not sure what the limit is; up to three homes, perhaps? Not sure. Anyway, because the homes are connected in parallel, it’s conceivable a power disruption in one home could affect the others. However, as others have mentioned, each home is protected by a main circuit breaker in the main panel (usually 200 A), and each branch circuit in each home is also protected by its own circuit breaker. An overload or short in a branch circuit shouldn’t have much affect on the other homes because the circuit breaker for the circuit should quickly trip. However, intermitting shorting inside the breaker box could be a real problem if it’s occurring between the circuit breakers for the branch circuits and the main circuit breaker. That’s because the main circuit breaker doesn’t want to trip unless it sees hundreds of amps, and intermitting shorting inside the breaker box might not trip it. In such a scenario, it may cause disruptions in the neighbor’s electric.
I don’t know which campus it was at (Thornbury High has gone through some name and location changes). I won’t be able to ask for more information until later in the new year.
That guy must tell the story every opportunity he gets!
The idea of everything going dark reminded me of something from my wife’s childhood in Brazil.
Blackouts in 1960s Rio de Janeiro were far more common than in the USA.
Whenever the lights went out, people would look outside and say “was it everywhere or just here?”–but in Portuguese the question was “Foi geral?” (was it general i.e. not local)? Since she was probably five years old, she heard “Foi Geraldo?” and she spent her early childhood wondering who this guy named Geraldo was and why didn’t someone make him stop messing with the lights!
I had that happen with the transformer on the pole right outside my bedroom window, and what an amazing sight that was!
I took photos of the bits I found scattered on the street the next morning: random bits of stuff
And I posted the photo on the Straight Dope for people to explain what the bits were. Apparently, by the age of the photo, this happened 15 years ago! Wow.
You’ve some good general advice here so I’ll not waste time nit picking non safety related errors in your post. I do however take issue with the above mentioned statement (bolded) as inherently unsafe…not to mention unfair to qualified (real) electricians.
Under the circumstances delineated above, no competent electrician would advise a homeowner over the phone to attempt to reset a main (breaker) with water running out of the panel. NO EXCEPTIONS.
your house would not have triggered a neighborhood blackout UNLESS you had a backup generator. If the generator wasn’t hooked up correctly, there could be backfeed to the line. This is very dangerous to a lineman and has resulted in fatalities in the industry. That being said, anything could have caused the neighborhood blackout. The main circuit breaker in a substation might have tripped; although someone mentioned the recloser which attempts to restart in mili-seconds up to 3 times. However the blackout would affect a huge section of homes, businesses, etc. Someone could have crashed into a pole, hit a transformer on ground level or water could have gotten into the electrical vault, downed wires. You can always contact your service provider to find out about outages.
With your case, you also had water in your main circuit panel. NEVER attempt to turn it back on when it is still wet. It must be completely dry first. You also need to turn off any load prior to flipping the breaker. Glad nothing happened to you. Again, contact your energy provider.
3 amps sounds about right on the high side of the X-former @ around 7500-V. That would be appx. 110 amps @ 240 volts divided by however many (1-?) homes… However, YMMV based upon the supplier. The fuse link (determined by the local supplier) on the transformer supplying your home determines the drop out current they wish to tolerate.
Around here (Ohio) it’s not a breaker that automatically resets, but rather a current maximum link (fuse) that permanently interrupts the circuit and requires a manual reset on the pole.
So yes, if you’re living in an armoury, a fault can take out the neighborhood.