A transfer switch is the switching device that transfers power from one source to the other, typically the Mains power supply & a back-up generator. An ATS is an automatic transfer switch, meaning the system works automatically to quickly transfer load to a reliable source in the event of a power failure.

In normal operation the mains supply is healthy so the Mains power is switched through to the load, the ATS controller continuously monitors the quality of the mains supply then should the quality of the mains power supply fail completely or just deviate’s outside of healthy limits the ATS will call upon the generator to start-up & provide power.

The ATS then recognises the generator power supply & if within healthy parameters disconnects the Mains supply from the load then switches the generator supply through to the load. The ATS then continues to power the load on generator power, as long as the generator is healthy & the mains supply is not.

Whilst the site is operating on generator power the ATS is continuously monitoring the mains supply & once it is restored to within healthy parameters for a given time the ATS disconnects the generator supply from the load then reconnects the mains supply through to the load.

The site is now restored back to the normal Mains power supply & the generator is no longer required so it is signalled to cool down & stop awaiting the next start signal.

There are several modes that an ATS can operate in & be controlled but we will cover that in another FAQ, at PGS standard ATS’s are stock items & are available for most power ratings.

To ensure minimum downtime during installations all our ATS’s are set-up & bench tested before being set out to work. We can also customise or special build an ATS to suit any application or requirement.

If you would like more information on what type of transfer switch will best suit your application, give our team a call on 08 8349 7854, or send us a message.