The Siemens 5UB1556 is the premium model in the DELTA i-system 5UB155x Schuko socket range, combining an integrated labeling field, LED operating display, increased touch protection, and built-in overvoltage protection in an electric white finish. Rated at 10/16 A / 250 V AC, it fits a standard 55 × 55 mm frame for flush-mount installation. Screwless plug-in terminals keep wiring fast and secure.

What does the built-in overvoltage protection actually do?

The 5UB1556 integrates a surge protection element (Überspannungsschutz) directly into the socket. When a voltage spike arrives on the circuit — from a nearby motor switching off, a lightning strike on the distribution network, or grid instability — the protection element clamps the excess voltage before it reaches the plugged-in device. This is not a substitute for whole-building surge protection at the distribution board, but it adds a last line of defense at the point of use. For equipment that is expensive to repair or replace — laboratory instruments, medical devices, IT servers, AV equipment — having surge protection at the socket reduces the chance of damage from internally generated switching surges that whole-panel protectors may not catch.

When is the 5UB1556 worth the premium over the 5UB1553?

The 5UB1553 offers the same labeling field, LED, and touch protection but lacks overvoltage protection. If the equipment plugged into this socket is a standard desk lamp, phone charger, or vacuum cleaner, the 5UB1553 is the rational choice. If the socket feeds a piece of equipment whose replacement cost — or downtime cost — dwarfs the price difference between the two models, the 5UB1556 pays for itself the first time it catches a surge. Typical applications include dental and medical examination rooms, server racks, laboratory benches, and high-end AV installations.