<P> A transfer switch is an electrical switch that switches a load between two sources . Some transfer switches are manual, in that an operator effects the transfer by throwing a switch, while others are automatic and trigger when they sense one of the sources has lost or gained power . </P> <P> An Automatic Transfer Switch (ATS) is often installed where a backup generator is located, so that the generator may provide temporary electrical power if the utility source fails . </P>

What is the purpose of a transfer switch