REA 105 is an extension unit designed to be used together with the arc protection relay REA 101. The function of the unit is to detect light and to carry out tripping, if the REA 101 unit provides an overcurrent signal at the same time, or delivers a trip command.
The use of extension units allows the protection area to be extended and the protected object to be divided into smaller areas. Thus a more selective system is obtained.
- Loop-type or radial sensor fibre for arc detection.
- 2 high-speed semi-conductor outputs for tripping.
- Signal relay activated by light detected by the sensor fibre.
- 3 RJ-45 ports for the connection of REA 101 relay and extension units.
- Circuit-breaker failure protection. Delayed light signal to REA 101, which opens the higher-level circuit breaker.
- Self-supervision unit monitoring operating voltages and the sensor fibre loop.