The Siemens 5SP3716-2KK02 is a 1-pole main miniature circuit breaker (SHU) from the SENTRON 5SP3 series, rated 16 A with an E tripping characteristic at 230/400 V AC, 50 Hz. Mounts on a 40-mm busbar system per DIN 43870 Part 2. The 1.5 width units and 89.5 mm depth fit the lower section of a meter panel.
That's high for a 1-pole 16 A device; it's sized for the high fault levels at the incoming side of a meter panel, not a sub-distribution board. The 6 kV rated surge voltage resistance (overvoltage category IV) confirms it's designed for the utility-side interface where lightning and switching surges hit hardest. The E tripping characteristic has a magnetic trip threshold higher than a C curve. This delays instantaneous tripping so a downstream MCB clears a fault first. Rated insulation voltage 690 V and pollution degree 3 mean it's suitable for the 230/400 V three-phase networks common in European infrastructure, even in dusty or conductive environments. The IP40 rating (with connected conductors) is typical for enclosed panel mounting — no special sealing needed inside a meter cabinet.
Infeed is via box terminal at the top; outgoing feeder uses a spring-loaded terminal at the bottom. The switch position indicator shows OFF = green, ON = red — a quick visual check during commissioning or troubleshooting. The locking slide accepts a padlock, wire seal, cable ties, or Antilux seal for tamper-proof metering applications. Mechanical life is 20,000 switching cycles typical — fine for a main breaker that sees infrequent manual operation, not a daily-switched load. Shock resistance is 30 g for 11 ms, vibration 2 g per IEC 60068-2-6, so it holds up in transport and seismic zones.