Automatic Transfer Switches (ATS) are typically used to provide resilience for smaller uninterruptible power supplies (below 10 kVA) that can’t operate in a parallel configuration.
The ATS has two AC input power sources (‘A’ and ‘B’) and if/when one of these fails, the loads are automatically and instantaneously transferred to the other.
Automatic Transfer Switches like Riello UPS's Multi Switch ATS can also be used instead of a Power Distribution Units (PDU) for plug and play loads. In addition, ATSs protect against short circuits and offer the ability to switch output power connections on and off remotely over a network.
The ‘A’ and ‘B’ power sources feeding an Automatic Transfer Switch can be configured in a variety of combinations:
- ‘A’ supplied from the output of the UPS and ‘B’ from the mains supply
- Both ‘A’ and ‘B’ supplied from two separate UPS outputs
- Both ‘A’ and ‘B’ supplied from two separate mains supplies.
The above example in the image highlights an ATS with two input supplies and up to eight outputs.