What is the voltage at your receptacle?

Hello, My electrician measured my dedicated wall receptacles at 124 volts each. I know that the proper range should be about 117-120 volts (USA). I was wondering what some of you have measured your wall power at and also if you think that 124 volts is too much? There is an electric company's power transformer on the back side of the half acre of property that our home is on. Our house could very well be the first house in line past that transformer. Thanks! Stan
how did the electrician measure the voltage at the receptacle? With a load connected, or no load connected? The proper way is with all intended loads connected. A 124Vac unloaded reading would not be unusual.

What type of meter did he use? Digital multimeter? True RMS? When was the last time the meter was calibrated?

Loaded readings at my audio recepts measure an average of around 122/123Vac.
Mine are consistently 124V true RMS unloaded.

Hi Jim and Arthur, My electrician measured the receptacles without a load connected. I have no idea what kind of multimeter he used. I'll be buying a multimeter in the next few days to recheck my receptacles. What is true RMS? Thanks for writing. Stan
True RMS takes time-varying and nonsinusoidal waves into account. This isn't a big deal when you are measuring line voltage because the 60Hz cycles are very regular but when you measure frequency-varying or complex waveforms, you need a much smaller calcualtion window - which is casually called "true RMS."

If you are getting a digital multimeter (DMM is the common abbreviation), I would recommend Fluke or Tektronix. I am partial to Fluke but the difference between the two is about like the difference between Ford and Chevrolet. Higher priced versions have better resolution and bandwidth (sound familiar?) and so they are "true RMS" capable, and clearly labeled as such. It just means they are more accurate but is the difference worth the extra cost? Well, you know what an audiophile would say.... :)

There are two standards for utility voltage. One is plus or minus 5 percent (114 to 126 volts RMS) which is "normal" and, in most cases, the utility is not obligated to correct or be liable for damgage to your electronics if the voltage falls within this range. The second range is 91.7% to 105.8% (110 to 127 volts) which is considered "acceptable" and the local gubment regs will have a say as to whether this is also litigation-free. Both are ANSI standards, and are recommended; not written in stone.

Is 124 volts too much? Not really. Most electronics are designed and built with the knowledge that voltage varies. Typical circuit devices, and more importantly insulators, are rated for 600 volt withstand. Also, RMS voltage is an average of sorts. In simple terms it means 70 pecent of the peak voltage. So the wall voltage of 120 volts, which is RMS, is actually 170 volts at peak.

But the other factor to consider is that the power to your house could be 120/240 on the nose and you have a problem at the service panel and ground which may cause one leg to read higher than the other. Your electrician should have checked that in addition to the outlets.
The voltage in my neighborhood (Bethesda, MD) is quite consistent, I typically see 117-120 volts all the time. This is based upon the display on my TrippLite UPS that is used to provide backup power to my main computer system. I have seen it dip as low as 116V and go as high as 121V, but only for the briefest of moments.

I live in a rural area, there is a tranformer quite near to my house.
On a dedicated circuit, I have a Furman PL Pro-D power protector, which has a digital voltmeter built in.
I was constantly seeing high voltages displayed on that meter. 126v not unusual, and often 129-130v. Of course the Furman cuts out at overvoltage. It was happening frequently - sometimes every night. In the middle of watching TV, or a DVD, or listening to music - very annoying.
I called the power company, and they pretty much just shrugged. Maybe it could be fixed, they said. But I have an electric pottery kiln, and the high voltage is an advantage (cuts firing time) so I let it go.
I got a PS Audio power regenerator, and now my voltage is steady as a rock, and right where I need it.
124 volts +/- ,2 volts.
The two legs at my breaker box read 119.8 volts and 121.7 volts.

I have all my stereo dedicated runs connected to the 121.7 phase and noisy appliances such as refrigerator, TV, and bathroom outlet used for hair drier are all on the 119.8 V side.