What the ratings mean for fit
The Siemens SENTRON 5SU9304-0KK16 is an RCD-operated circuit breaker — an RCBO — combining overcurrent protection and 30 mA residual-current protection in a single 18 mm-wide module. The B-curve trip characteristic (per EN 60898) means it clears short-circuit faults at 3–5× rated current, suited for resistive and general-purpose loads where inrush is modest. The 10 kA breaking capacity at 400 V is the maximum fault current it can safely interrupt without upstream cascading — adequate for most residential and light commercial distribution boards. The 30 mA residual trip covers personnel protection (indirect contact) and fire prevention in standard AC circuits.
Deployment context
Mounts on DIN rail in a distribution board; the 18 mm width (1 modular unit) saves panel space. IP20 applies only when the board is closed and conductors are connected — not for open-panel or wet-area use. Rated for any mounting position, so orientation in a crowded enclosure is flexible.
Thermal derating and ambient limits
Rated 16 A at 30 °C ambient; at 40 °C the continuous current drops to 15.04 A, at 50 °C to 13.92 A, and at 55 °C to 12.96 A. If the distribution board runs warm — near other breakers or in a sealed enclosure — the 40 °C or 50 °C row is the one that governs the load you can actually protect. The unit survives -40 °C storage and 75 °C maximum, but the operating derating curve is what matters for continuous load.
Lifecycle and sourcing
Listed as current-production (active lifecycle). Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.