ATS / Automatic Transfer Switch / How Inside Look like /how it's work

AUTOMATIC TRANSFER SWITCH (ATS) GENERAL
The automatic transfer switch shall be industrial (NOT residential) grade and
furnished so as to maintain system compatibility and local service responsibility
for the complete emergency power system. It shall be listed by Underwriter's
Laboratory, Standard 1008, with circuit breaker protection afforded by the
generator breaker. Representative production samples of the transfer switch, which
have been demonstrated through tests, shall withstand 10,000 mechanical operation
cycles (minimum) without failure. One operation cycle is the electrically operated
transfer from normal to emergency and back to normal. The manufacturer shall
furnish complete schematic and wiring diagrams for the particular automatic
transfer switch and a typical wiring diagram for the entire system showing all
components, relays and part numbers. This ATS shall be an integral part of the
generator set and be secured to the weather-proof enclosure. All wiring and
connections to integrate the ATS into the generator output shall be made by the
vendor before acceptance by the Government.