What this RCBO carries
The Siemens 5SU9307-7QS20 is a Crabtree Polestar RCBO — a combined residual-current circuit breaker with overcurrent protection, rated at 16 kA breaking capacity, Type A sensitivity, 30 mA residual current, C20 characteristic curve, and Long Tail termination. Type A detection means it trips on sinusoidal AC and pulsating DC residual currents — the minimum for circuits feeding single-phase electronics, switch-mode supplies, or variable-speed drives where pure AC-only (Type AC) protection would miss a fault. The C20 curve (C characteristic, 20 A rated current) handles moderate inrush from motorized loads or capacitive banks without nuisance tripping, while the 30 mA residual threshold provides personal protection against direct-contact faults.
Lifecycle and sourcing posture
This RCBO is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.
Integration into the panel
The Long Tail designation refers to the neutral pigtail connection — a flying lead that routes to the neutral busbar, typical in UK-style consumer units and distribution boards where the RCBO mounts on a DIN rail and the neutral bar sits separately. Snap-on DIN rail mounting, 2-module width. Verify busbar compatibility (Crabtree Polestar range uses a specific busbar pitch and fork profile) before ordering for a retrofit.