Power supplies common in the US
Here are some common power supplies for residential and commercial buildings.
In the feild as an installer the term 277/480 is referred to as high voltage and 120/240/208 as low voltage. Generally speaking that is.
48 volts and below are also referred to as low voltage.
With that in mind when your on a project that has a combination of ALL these voltages make sure you clarify you meaning when talking with others.
Excluding the 48 volts and below lets take a look at several types available from the utility company:
Note not all voltages mentioned will be available in different parts of your city there fore a transformer may be required to obtain low voltage power supply.