hi, i was checking a 110-120vac outlet the other day for voltage, and noticed that it read 125vac. i know the voltage varys a few volts one way or the other, but usually all the regular 110-120vac volt outlets read between 110-120 with my dmm, i tested them with and analog meter too, and got the same 125vac. is this norm? also, 220-240vac outlets are 248-250vac when tested. i dont think its a biggie, but, could there be a problem with a transformer outside the house on a pole somewhere??? maybe it is failing?
If this is true, you are seeing a high voltage, it is a problem. I have never seen this, just lower voltages from old decaying wiring, which damages electrical devices. Those devices have power supplies that have limited tolerances (like your computer). I would contact an electrician or your local/town building office.
The POCO has a range of voltages it is required to supply and stay within.
125 & 250 are no problem at all. 250v is within 5% of 240v.
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.
Answers based on the 2008 & 2011 NEC.