He said the panel was dry at the time they were trying to reset the breaker. If there is water in an electrical panel don’t even touch the panel wold be my advice.
“The transformer blew” is a common utterance. But usually what happens is that the transformer has been protected by an expulsion fuse. During an overcurrent event, the fuse is designed to explode, interrupting the conductive path and extinguishing any electrical arc that may otherwise form. They’re effective, but damn loud. When they activate, there’s no reset: a utility worker has to get there and manually replace it with a new one.
Arc flash is a potentially lethal concern on high voltage systems seen in industrial settings. But it doesn’t appear to be a major hazard in residential settings:
In general, arc flash incidents are highly improbable on systems operating at less than 208 volts phase to phase (120V to ground) when fed by less than a 125 KVA transformer (very typical of most office and home environments). 120 volts does not provide sufficient energy to cause an arc flash hazard. Most 480V electrical services have sufficient capacity to cause an arc flash hazard. Medium-voltage equipment (above 600V) is higher energy and therefore a higher potential for an arc flash hazard.
Having said that, if I were going to flip a residential main (100-200 amps) breaker, I might elect to wear safety glasses.
Yeah, it’s just the common usage. I have actually seen the aftermath of a transformer actually failing- it set the pole on fire and all sorts of other crazy stuff. Put the power out for a good long time also.
This thread reminds me of something that happened to me recently. I had an outlet go bad in my garage (our tankless water heater was plugged into it and the first indication was that we had no hot water). Replacing an electrical outlet is a pretty simple task most of the time, but my father-in-law was there anyway because (unlike me) he actually has a little training as an electrician. (I am a professional at fixing computers but not at fixing what the computers plug into.) Anyway, I was attaching the new outlet to the wires and right as I hooked up the first wire all the lights went out in the garage. I was startled and panicked, wondering what I did, until my father-in-law reminded me that the garage lights were on a motion sensor and it must have timed out right at that moment. He waved his hand in the air and the lights came back on.
The outlet installation went without a hitch, again it’s extremely easy as long as you take proper precautions (shut off the breaker, keep track of where the wires are supposed to go) but I will never forget the process just because of how terrified I was that I had somehow blown all the power in my garage (or the whole house).
Atamasama I had something like that happen to me at work one time. When I threw the knife switch on an elevator all the store lights went out. This was at 9:59 and the store opened at 10;00. I thought now what did I do and how long will it be before I can get the power back on. Wasn’t anything I did. At the same time as I was closing the knife another engineer was finishing up working on the Emergency generator transfer switch. He grounded something and tripped the buildings main GFI breaker.