Tronic Automatic Transfer Switch 400A

Our review

This is a 400A automatic transfer switch from Tronic, built around a microprocessor controller that watches the incoming mains supply. According to the manufacturer, it responds to three conditions: loss of power, over voltage and under voltage phase. That makes it a candidate for anyone running a generator or backup supply who wants the changeover handled automatically rather than by hand.
Before buying, confirm the 400A rating matches your load and that your generator's control wiring is compatible with an ATS of this type. Ask the seller for the full changeover sequence and terminal details, since none are listed here. Compare against contactor-based ATS units and against smaller-rated switches; the deciding factors are usually current capacity, how the controller senses voltage, and whether it handles the phases you actually have. It is available on Sokonia.