What this RCD is and what it does
The Siemens SENTRON 5SM2347-0 is a 4-pole residual current device (RCD-unit) designed for AC residual current type, tripping instantaneously at 30 mA fault current. Rated 100 A at AC, it handles the full branch load while protecting personnel against earth faults — the 30 mA threshold is the standard for personal shock protection in most residential and light commercial panels. The 4-pole construction (switching all three phases plus neutral) makes it suitable for three-phase circuits where neutral continuity must be maintained through the device.
Temperature derating — real-world capacity
The 100 A rating holds at 40 °C and 45 °C (93 A), then steps down: 90 A at 50 °C, 87 A at 55 °C, 85 A at 60 °C, 83 A at 65 °C, and 80 A at 70 °C. If this RCD sits in a crowded enclosure near other heat sources, the 70 °C derated figure (80 A) is the one to design for — the full 100 A only applies in a cool, ventilated panel. The device is rated for overvoltage category III and pollution degree 2, typical for fixed-installation distribution boards.
Panel fit and mounting
Occupies 5 modular width units on a DIN rail (REG fastening method), with a 124 mm width and 70 mm depth. Mountable in any position; supply can enter from top or bottom. IP20 rated once installed in a distribution board with conductors connected — not for wet or dusty environments. The 70 mm installation depth fits standard shallow enclosures, but check gland-plate clearance if using deep cable entries.
Lifecycle and sourcing reality
Marked as current production — no end-of-life notice on record. This is a standard-catalog SENTRON RCD, widely specified across European and export panels. Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time. For a BOM freeze or last-time-buy, the 50 Hz operating frequency and AC-type residual current are the binding constraints — verify the installation's frequency and fault-current type before committing.