The Siemens SENTRON 5SU1344-1RC40 is a 4-pole RCBO (residual current circuit breaker with overcurrent protection) rated 40 A with a C tripping characteristic and 30 mA AC-type residual current detection. It occupies 7 modular width units on a DIN rail and is designed for 50 Hz systems. The C-curve means it handles moderate inrush — typical for motor and lighting circuits in commercial and light industrial panels — without nuisance tripping, while the 30 mA sensitivity provides personnel protection against earth faults.
Breaking capacity and standards
Rated breaking capacity is 10 kA per EN 60898 and 15 kA per IEC 60947-2. That 10 kA figure is what governs for residential and commercial distribution board applications under the MCB standard; the 15 kA rating under the industrial standard gives headroom for higher fault-current installations. Insulation voltage (Ui) is rated at 440 V, overvoltage category III, pollution degree 2 — standard for fixed-installation switchgear in a distribution board.
Mounting and environment
Mounts in any position on a DIN rail. Depth is 70 mm, width 126 mm (7 MWU), height 90 mm — fits standard distribution board cutouts. The IP20 rating applies when installed in a distribution board with connected conductors; the enclosure itself provides the required ingress protection. Ambient range from -40 °C to 75 °C covers most indoor and sheltered outdoor enclosures. Supply can enter from top or bottom, which simplifies wiring in tight cabinets.
Lifecycle and sourcing
The 5SU1344-1RC40 carries a current lifecycle status. It is sourced and quoted to order against an RFQ through independent distribution channels; availability and current pricing are confirmed at quote time. No official successor has been published — this remains the active order code for a 40 A, 4-pole, C-curve, 30 mA AC-type RCBO in the SENTRON range.