PDUeX 16Amp 230Volt Automatic Transfer Switch (ATS) is a single Phase Dual Input. When Input A falls  below 168 VAC and Input B is valid, the output is automatically transferred to Input B. The output is transferred back to Input A when Input A is valid and rises above 178 VAC. This high speed transfer rate ensures that the transfer is transparent to the sensitive equipment. The two sources are not required to be in phase. This is an effective solution that builds in redundancy and increases the AC power availability of connected equipment. If the dual input power is fed through two independent AC sources, then the system availability is increased and the dual input advantages are fully used.