Is the maximum voltage in an ac circuit when the rms voltage is 110 volts?

Answer 1

It depends on the equipment. The power supplies on most devices can only handle a specific voltage and still work properly. Some, for instance some cell-phone chargers, can handle a range of voltages, say from 110 to 240, which lets them operate in both the States and the UK (where the standard home/office voltage is 230 Volts). Check the label on the back of the device; it will usually show the operating voltage required. Asking the maximum voltage for 110 equipment is valid. 110 means AC voltage that averages 110 volts as it swings above and below 0 volts. The label on a device typically will not tell you the maximum voltage it can withstand if it is plugged into a U.S. 110 volts AC outlet.

U.S. houses are wired with 2 hot wires (each 120 Volts AC but opposite of each other) and a neutral wire (0 volts). That way electrical outlets can be wired for 120 Volts AC if they use a hot wire and the neutral wire... or 240 volts AC if they use both of the hot wires.

If the neutral line goes bad then the 120 volts AC outlet floats anywhere from 0 volts to 240 volts. I have been in a house when this occurred (the neutral corroded on the transformer that fed several houses). Supplying too high a voltage burned out an air conditioner, a refrigerator, and an incandescent bulb actually burst, scattering glass close to my wife. The air conditioner threw out a lot of smoke so there was a danger of fire.

In the U.S. a typical 120 volts AC circuit often has a higher voltage. I have seen specifications and codes that put an upper allowable voltage at 120 volts AC, 137.5 volts AC, and 150 volts AC. Every electrical device has different limits but I would not subject anything built for 120 volts AC to voltages higher than 132 Volts AC unless I had specific knowledge that the device could handle the higher voltage.

Answer 2

Answer for USA, Canada and countries running a 60 Hz supply service.

There are three insulation rating for voltage that most people will encounter. The maximum voltage categories are 300, 600 and 1000 volts. So to answer the question 110 volts falls within the 300 volt rated insulation rating.

Answer 3

If there is no DC offset, the peak AC voltage value will be 155.6 volts (110 x sqrt(2)).