The Siemens SENTRON 5SM2627-0 is a 2-pole instantaneous RCD (residual-current device) for AC-type fault currents. It carries a 100 A rated current at 50 Hz and trips at 300 mA residual — a common spec for general-purpose shock protection and fire prevention on sub-distribution boards. It's designed for the 5SP4 distribution board family and mounts on a DIN rail (REG fastening) in any position, occupying 4 modular width units. Supply connects top or bottom.
Ratings and derating
The 100 A rating holds at 40 °C and 45 °C; above that it derates linearly to 80 A at 70 °C. If the panel runs warm — say above 50 °C — you're working with 90 A available, not the full 100. That matters for continuous loads like EV chargers or UPS feeds. Insulation voltage (Ui) is rated 460 V, overvoltage category III, pollution degree 2. Surge current withstand is 1 kA, surge voltage withstand 4 kV. The unit is not adjustable on either trip current or off-delay — it's a straight instantaneous 300 mA AC type. Operating temperature range is -40 °C to +75 °C, which covers most indoor and sheltered outdoor enclosures. IP20 with distribution board installed — so it's not for wet locations unless the enclosure provides the seal.
Panel fit
Dimensions are 71 mm wide by 90 mm tall by 70 mm deep (installation depth also 70 mm). That's a 4-MW footprint on a DIN rail — standard for a 2-pole 100 A RCD. The depth is shallow enough that it won't conflict with a 100 mm back-box depth in a typical TP distribution board.