RCCB for 63 A feeder circuits — Type A, 30 mA, instantaneous
The Siemens 5SM3316-6BA is a 2-pole residual current operated circuit breaker (RCCB) from the SENTRON 5SM3 series, rated 63 A at 230 V AC with a 30 mA residual trip threshold and Type A fault-current sensitivity. The 30 mA trip level is the standard for personnel protection in most IEC 60364 installations — it clears earth faults before they reach the let-go threshold. The instantaneous design (no intentional delay) means it trips within the first cycle of a fault, which is the correct choice for feeder circuits where selectivity with downstream RCBOs is not required.
Short-circuit withstand and installation constraints
The unit carries a 10 kA short-circuit current rating per IEC 60947-2, which is the standard breaking capacity for a distribution-board RCCB in a 230 V TN or TT system with a typical prospective fault level at the board. It snaps onto DIN rail (REG profile) and occupies 2.5 modular width units (roughly 45 mm) — a compact footprint for a 63 A device. The IP20 rating applies once the distribution board is installed and conductors are connected; the RCCB itself is finger and back-of-hand safe per the touch-protection spec. Screw terminals accept 1.5 to 25 mm² solid or stranded copper, with a tightening torque of 2.5 to 3 N·m.