Help me diagnose an electrical problem

I think we had a power surge last night. My wife said that at around 5:30 the lights went out in some of our rooms,and when my wife looked out across the neighborhood the street lights were out and none of the house had other lights in them.

Power is now on in all of the house except a few rooms. I wend down to the fuse box reset all of th fuses in the fuse box but still no luck. Time to call an electrician. But here’s the weird thing. I had a surge protector plugged into one of and it has an led labeled “not grounded” that is on so long as the protector is plugged in to the “non-working” outlet. If I unplug it the light goes out.

So two questions.

  1. What likely happened and how easy is it going to be to fix. I probably can’t know for sure until the electriciaan gets here and diagnoses things, but give me your best guess ideally with probabilities. is this likely something that can be fixed at the fuse box, and probably the room in question for testing, or is he likely going to need to lay down wire throughout the house.

  2. What is the deal with the surge protector light. Does this mean that there is still some very small current running through the outlet that is enough to run the light but not the fan I was using to test the outliet. Or does my relatively cheap surge protector have an internal battery that is enough to detect that its plugged in and turn on the light?

I had a surge last week that knocked out all mu surge protectors. Is there any item that was in use in any of those rooms when the power surge hit?. My first guess would be it fried one of your connections at a plug so everything down the line would be out. Last week was the first time I had experienced a surge like that. 2 of my surge protectors started on fire.

Paging @Bob_Blaylock for an electrician’s POV.

Well, you definitely need a sparky. Did you open up the panel and inspect the innards? I’d want to make sure nothing is fried in the meter base or the breaker box. Also, what kind of fuses/breakers do you have? The main breaker/fuse and all the individual breakers should protect the rest of the house, but shit happens. If you’re comfortable opening up the panels, I would do it–you could have a fire hazard.

You may have lost one leg of your 220V service (so you only have 1/2 of your circuits) , or you may have lost the neutral/ground and now have a floating ground with that no ground indication. Either way it does sound like the power companied responsibility. Do you have any 220 V appliances and are they working? (i.e. electric hot water, most heat pumps except very small minispilts, electric dryer, electric range). If you lost one leg they will either not work or work very poorly and I would suggest not using them after testing.

Yes, this is almost certainly the issue.
The bad leg probably has just enough voltage to light the indicator in the surge protector, but not enough to actually run any appliances or lights.

  I don’t have much to add to what others have already said.  It’ll take an electrician to diagnose and repair whatever has happened to your home’s wiring; and I wouldn’t even think of trying to diagnose it without the chance to examine it firsthand.

  One thing that I will add is that you should probably replace all your surge protectors. Most of them—at least the cheaper ones—are based on metal oxide varistors, which are only good for absorbing one good surge; and there is no non-destructive way to test them to determine if they are still good.

Ditto, also being an electricain myself it sounds like a phase was lost. And do not take the panel cover off or try to diagnose this yourself for safety reasons. Plus you want the sparky to be the first person to put hands on this to ensure proper diagnosis.

Thanks all for your everyone’s help and sorry for not respondoing earlier. Just to reassure everyone there is no way that I am going to try to handle this myself. I was just curious as to what was wrong and what the repair was likely to require. The limit of my willingness to touch electrical stuff is to swtich breakers on and off and change lightbulbs.

Can you clarify what it means to lose phase and what is required for the electrician to repair it?

Here in the US (are you in the US?) it’s typical to have 2 120V feeds from the power transformer outside your house. Individual 120V circuits are on one or the other leg, while higher powered loads such as a dryer or electric stove bridge the 2 legs for 240V power. So, one way to assess if you have lost a leg is if any high power appliances still work–the breakers will be double width. If you and your neighbors have lost a leg, it’s probably something your power supplier will have to fix–i.e. it’s on their side of the meter. On the other hand something may have fried in the meter base or breaker panel itself, in which case it will be your responsibility. Either way you will need an electrician to diagnose, although it’s worth reaching out to your utility also.

OK makes sense thanks a bunch.

  Probably more apropos to describe it as a single 240V feed, with a tap halfway.  That tap becomes the neutral, and the two ends are the two phases, 180° off from one another, each 120V from the neutral.

  Most branch circuits are then are fed by one neutral, and one of the two ends/phases, giving you 120V on each such circuit.

  The 240V branches, to feed high-powered things such as stoves, dryers, HVAC, and such, are fed from both ends, rather than from one end and a neutral.

  In most commercial applications, the power is three-phase rather than two, with the phases being spaced 120° apart.  As with residential, the 120V branches are each fed by the neutral, and one of the three phases.  Higher-volt circuits, fed from two phases rather than from one phase and the neutral, are 208V rather than 240V; as the phase-to-phase difference is √3 or approximately 1.732… times the phase-to neutral, rather than twice the phase-to-neutral as in a two-phase system.

  Then there’s the 480V three-phase power, also common in commercial and industrial settings.  Here, the 480V is the phase-to-phase voltage.  Neutral-to-phase is 1⁄√3 of that, which comes to 277V.  It’s common for 277V to be used for lighting.