Panel-builder commissioning note
The Siemens SENTRON 5SQ3270-1BA16 is a 2-pole miniature circuit breaker (1P+N) with a C-curve trip characteristic, rated 16 A at 240 V AC, 50 Hz. The neutral pole switches, so it isolates both line and neutral on a fault — no separate neutral disconnect needed downstream. Energy limiting class 3 means it clips the let-through energy enough to protect downstream wiring within its rating.
Occupies 2 width units (roughly 36 mm) on a standard DIN rail. Installation depth is 55 mm, so it clears most shallow enclosures. Overvoltage category 3 suits fixed-installation distribution boards downstream of the main incoming supply.