The numerical busbar protection REB500 is designed for the high-speed (sub-cycle), selective protection of MV, HV

and EHV busbar installations at a nominal frequency of 50, 60 Hz The modular system structure is enabling the protection to

be easily configured to suit the layout of the primary system.

The flexibility of the system enables all configurations of busbars from single to quadruple, with transfer buses or

ring busbars and 1½ breaker schemes to be protected.

In 1½ breaker schemes the busbars and entire diameters, including Stub/T-Zone can be protected. 

An integrated tripping scheme allows saving external logics as well as wiring.

The system is scalable for up to 60 feeders (bay units) and a total of 32 busbar zones.

The numerical busbar protection REB500 detects all phase and earth faults in solidly grounded and resistivegrounded power systems and phase faults in ungrounded

systems and systems with Petersen coils.

Main features

Low-impedance busbar protection

· High functional reliability due to two independent measurement criteria:

– stabilized differential current algorithm

– directional current comparison algorithm

· Short tripping times independent of the plant’s size or busbar configuration

· Phase Segregated measurement

· Stub and T-zone protection

· Reduced CT performance requirements

– High through-fault stability even in case of CT saturation

– No switching of CT circuits