This paper presents a low-cost three-phase AC solid-state circuit breaker (SSCB) structure applied to medium and low voltage applications. The structure is primarily composed of a three-phase rectifier bridge and multiple series-connected power devices to increase the voltage-withstanding capability. These series-connected devices can be simultaneously controlled by a single driver. It can both assure optimal voltage balancing across multiple devices and effectively reduce cost and control complexity. SSCB has the advantage of fast interruption as opposed to mechanical circuit breakers. Compared to the conventional AC SSCBs with anti-series power devices in each phase, the proposed structure has lower power loss and fewer active devices. The experiment results from a 380 V/60 A AC prototype show practicability of the proposed AC SSCB structure.