Short Circuit Isolator

The RPU Short Circuit Isolator is designed to ensure maximum continuity and reliability in 100V return-loop loudspeaker systems used for Public Address and Voice Alarm (VA) applications. Fully EN54-17 compliant, it automatically detects and isolates short-circuit or open-line faults between two isolators, allowing all unaffected loudspeakers to remain operational. This guarantees that critical evacuation messages and alerts continue to be delivered clearly, even during a wiring failure.

Supporting up to 500 W / 100 V loudspeaker load per isolated segment, the RPU provides a fast fault response (<3s)with LED status indication for clear visual diagnostics. A local reset button is included to simplify system maintenance and fault recovery. The device operates directly from the ring driver’s DC carrier, requiring no external power supply, and its compact IP33 housing allows direct mounting on a loudspeaker fire dome for one-to-one supervision, or between loudspeaker groups depending on system design.

The RPU is ideal for large-scale distributed audio installations where system availability is essential, such as airports, public buildings, transport hubs, shopping centers, hotels, corporate facilities and other life-safety environments. By ensuring loop integrity, resilience and audio continuity, it forms a key component of a robust and certified Voice Alarm infrastructure.