What it is and what it does
The Siemens 5SV3347-6KL is a 4-pole residual current circuit breaker (RCCB) from the SENTRON family, rated at 80 A with a 30 mA trip threshold and Type A residual current sensitivity. It's designed for 400 V AC, 50 Hz systems and mounts on a standard DIN rail, occupying 4 modular width units (72 mm wide). Type A detection means it catches sinusoidal AC faults plus pulsating DC fault currents — common in modern loads with rectifiers and switching power supplies, like variable-speed drives, washing machines, or LED lighting. The 30 mA trip threshold covers personnel protection (hand-to-hand or hand-to-ground contact) under IEC 61008-1.
Rating so-what and derating
The 80 A rating holds at 40 °C ambient. Above that, the part derates linearly: 77.57 A at 45 °C, 74.59 A at 50 °C, 70.22 A at 55 °C, 64.47 A at 60 °C, 57.35 A at 65 °C, and 48.8 A at 70 °C. If this breaker sits in a warm enclosure — say a packed panel near a motor starter — you need to account for that derating at the design phase, not at commissioning. Short-circuit current rating is 10 kA per IEC 61008-1, with a let-through current of 7,100 A and a permissible I²t of 110,000 A²·s. That means it safely interrupts faults up to 10 kA without rupturing, and the let-through energy stays low enough to protect downstream wiring and devices. Surge current resistance is rated at 1 kA (8/20 µs waveform), so it handles lightning-induced or switching surges common in industrial environments without nuisance tripping.
Mounting and integration
Snaps onto a 35 mm DIN rail (REG profile), any mounting position. Depth is 70 mm, height 90 mm, width 72 mm (4 MW). The supply can enter from top or bottom, and the neutral is on the left (N left). IP20 with connected conductors — fine inside a distribution board, but not for washdown or outdoor exposure. Silicon-free construction, so it's safe for use in painting or coating lines where silicone contamination could cause fisheyes or adhesion failure.