Bad power company, the standard is 114-126V, 110-112.5V doesn't fit that
So I've always had from around 120 to 125 volts at my house, usually about 122ish. I don't really check it on a regular basis but I usually end up doing it every few weeks or so because of something that I am doing.
Anyway last week with the big wind storm out power went out for like 9 hours or so and when it came back on I noticed the lights seemed a little dimmer than usual and the microwave sounded a little bit different than it ever did before. Realizing this I decided I should check the voltage and that time it was 115 or so which is lower than it ever was before. After that I have been measuring it every day though I haven't been home lately because I'm staying at my grandparents house taking care of their animals while they are in Florida. Anyway two other times I measured the voltage I got 110 and the last was 112.5 volts. Contrary to common belief the standard is 120V not 110V even though they taught me in school that it was 110V. It was at one time but then it was changed to 120 in 1950 I believe.
So anyway I looked up the standards online to be sure and the standard for both the US and Canada is in fact 120V nominal plus or minus 5 percent and then it goes on to say that means the utility company is responsible for maintaining a voltage between 114V and 126V at the customers service panel.
So I'm thinking when I get back home I'll measure it every few hours and write it down and then average it out over a several day period and see what it averages to and if it is below 114 then maybe I should think about asking the electric company why. I would tell them that before it was usually around 122 up until the outage and after that it got to being much lower and below the standard. I could even tell them that I confirmed that with an oscilloscope dividing the peak voltage by the square root of 2. That's what I got for Christmas, a brand new BK Precision 30Mhz dual trace analog oscilloscope. I could also tell the power company that although the voltage is below threshold it is a nearly perfect sine wave because it is. When they hear all that they will know I'm not some idiot that doesn't know what he's doing or how to read a volt meter. Generally you don't use an oscilloscope to measure high voltage AC household power unless you know what you are doing otherwise you will shock yourself and or cause a short circuit.
Anyway last week with the big wind storm out power went out for like 9 hours or so and when it came back on I noticed the lights seemed a little dimmer than usual and the microwave sounded a little bit different than it ever did before. Realizing this I decided I should check the voltage and that time it was 115 or so which is lower than it ever was before. After that I have been measuring it every day though I haven't been home lately because I'm staying at my grandparents house taking care of their animals while they are in Florida. Anyway two other times I measured the voltage I got 110 and the last was 112.5 volts. Contrary to common belief the standard is 120V not 110V even though they taught me in school that it was 110V. It was at one time but then it was changed to 120 in 1950 I believe.
So anyway I looked up the standards online to be sure and the standard for both the US and Canada is in fact 120V nominal plus or minus 5 percent and then it goes on to say that means the utility company is responsible for maintaining a voltage between 114V and 126V at the customers service panel.
So I'm thinking when I get back home I'll measure it every few hours and write it down and then average it out over a several day period and see what it averages to and if it is below 114 then maybe I should think about asking the electric company why. I would tell them that before it was usually around 122 up until the outage and after that it got to being much lower and below the standard. I could even tell them that I confirmed that with an oscilloscope dividing the peak voltage by the square root of 2. That's what I got for Christmas, a brand new BK Precision 30Mhz dual trace analog oscilloscope. I could also tell the power company that although the voltage is below threshold it is a nearly perfect sine wave because it is. When they hear all that they will know I'm not some idiot that doesn't know what he's doing or how to read a volt meter. Generally you don't use an oscilloscope to measure high voltage AC household power unless you know what you are doing otherwise you will shock yourself and or cause a short circuit.