TRANSFORMER SITAS; PHASES:3; PN/PN(S6)(KVA):6,3 /28; UPRI(V):Y500-400/D289-230; USEC(V):Y 400 / D 230; ISEC(A):9,1; F(HZ):50...60; VECTOR GR./SHIELD WNG.:IIIIII0 /0; TA/ISOKL:55 /H; IP00; TYPE OF TERMINALS:SCREW CONNECTION; INSTALLATION:SCREW; EN 61558-2-1, -2-2, -2-4 UL/CSA-RECOGNIZEDCONTROL CIRCUIT TRANSFORMERISOLATION TRANSFORMER The 4AU 3-phase transformers are implemented as isolating, safety or matching transformers with different primary and secondary voltages and vector groups. They are suitable for a "fuseless design" due to their low inrush current and this is achieved with SIRIUS 3RV motor starter protectors/circuit breakers.