I wondered about the 110, 120 and 125 volt thing for years until I ran across an article that explained there really is no more 110 A.C. unless you have a really bad line. The voltage was increased so you will usually see more in the range of 120-125 volts. I went out to the trailer and my voltmeter registered 121 volts. When it drops down to 113 volts then it goes into the red area. Fortunately I have a Hughes Autoformer which will keep the voltage up or shut the system down should I hook up to a line with low or very high voltage.
'01 2500hd ext. cab, 8.1 litre gas, 5 sp. Allison auto
3.73 rear end
Mag-Hytec rear diff cover
Amsoil Dual by-pass oil filtration system
Amsoil synthetics all around
265 watt AM Solar, Inc. system