Transfer Switches

A Transfer Switch is an electrical switch that reconnects the power source from its primary source to a standby source. Switches can be manually operated or they can be automatically operated. 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. An ATS not only safely switches in the backup generator as a temporary source of electrical power; it also commands the backup generator to start up, it also continually monitors the primary feed source. It isolates the backup generator from the electrical utility when the generator is on and is providing temporary power. The control of a transfer switch may be manual only, or a combination of automatic and manual control. Isolation of the generator from the distribution system is required to protect the generator from overload, and to prevent accidental energisation of the service wiring.