The arc protection relay REA101, along with the extension units REA103 and REA105, are designed for the protection of medium- and low-voltage switchgear. The central unit type REA101 operates independently or together with the extension units REA103 and REA105. These extension units allow the number of sensor fibres to be increased, thus extending the area to be protected.
In an arc situation, the fault location is quickly localised by inspecting the area covered by the sensor fibre that detected the arc. The design of the extension units REA103 and REA105 is nearly the same. The main difference between the units is that the REA105 is equipped with two fast trip outputs, capable of opening, for example, the bus coupler or both circuit breakers of a duplex feeder. Thus, selective tripping is achieved. The arc protection relay REA101 is provided with two output ports, to each of which a maximum of five extension units can be linked.
Features
• Three-phase overcurrent function
• Loop-type or radial sensor fibre for arc detection
• 2 high-speed semiconductor outputs for tripping
• Relay output for tripping
• 2 RJ45 ports for the connection of extension units
• 2 opto-connectors for fast ON/OFF signal transfer between central units
• Circuit-breaker failure protection, i.e. delayed output for higher-level circuit breaker
• Self-supervision unit for monitoring the sensor fibre, operating voltages and cabling between central units and extension units