The AVS303 protects against over voltage and under voltage on any one of the three phases as well as loss of one or more phases. Indication and/or disconnection as a result of mains frequency error of phase sequence error is available as an option.

Fully automated switch with no moving parts, the AVS303 incorporates a contactor to switch the full load current (see the AVS3P-0 if you already have switching mechanism in place). The AVS303-xx is available in different sizes ranging from 23 amps to 1250 amps (the –xx relates to the model number, i.e. AVS303-23 is a 23 amp per phase AVS303).