Auto Transfer Switches (ATS)

An automatic transfer switch (ATS) is different to a generator  controller as it only monitors the mains and generator power but does not start the engine. The unit normally sits in a monitor panel and and has connections to the generator controller.

When the mains power fails the ATS gives a command to the generator controller to start the generator set. Once the generator set is up and running the ATS then switches over the power from mains to the generator. The ATS will then check the mains to see when the power returns, once the power returns the ATS will switch over the mains and then tell the generator to stop.