Voltage restraint overcurrent relay and protection assemblies
RXISK 2H/RAISK is used as a short-circuit protection for generators and also for other network applications, where a more sensitive short-circuit function is required compared to a basic overcurrent function.
The voltage restraint function is linear between a set voltage value and 25 % of that setting. The set overcurrent operating value is then reduced linearly with the reduced voltage as a result of the fault. The resulting fault current sensitivity is thus a function of the measured input voltage to the relay.
Standard IEC inverse characteristics as well as fixed time delays may be selected via the switches on the front of the relay. RAISK provides assemblies for single and multi-phase arrangements.
Main Features:
- Linear voltage restraint provides advantage of increased current sensitivity at reduced voltage. The relay provides an alternative to a non-directional circular impedance relay.
- Inverse and fixed time delayed operation for low-set stage. Instantaneous operation of the high-set stage.
- High-speed operation and low transient overreach
- Block or enable operation via binary input
- Four LED indicators