The Siemens 5SN6403-7CP is a 4-pole miniature circuit breaker from the SENTRON 5SN series, rated for 400 V AC supply voltage at 50 Hz with a C-curve tripping characteristic.
The 90 mm height matches the SENTRON compact family, so it rows cleanly alongside other 5SN or 5SL series breakers in a multi-way distribution board. Terminal capacity accepts solid conductors up to 35 mm² — sized for the incoming feed on a 4-pole submain.
Breaking capacity and standard compliance
Two breaking-capacity ratings apply depending on the installation standard. Under EN 60898 (household and similar installations) the breaker is rated 6 kA. Under IEC 60947-2 (industrial switchgear and controlgear) the rating rises to 30 kA — this is the figure a panel builder references when the breaker sits in an industrial distribution board with a transformer-fed bus.