Siemens Circuit breaker for transformer protection, size S0Product Overview The 3RV1421 1EA10 circuit breaker is designed for transformer protection in size S0 applications, featuring A release protection with an adjustable current range of 2. 8 to 4 A and short circuit release rated at 82 A. This motor starter protector provides specialized overload and short circuit protection for transformers and electrical loads, incorporating screw terminal connections and standard switching capacity for reliable