Measurement

The relay continuously measures phase currents and earth current. Earth current can be

measured using external core balance current transformer or can be calculated internally.

The relay has provision to display measured three phase current and earth current in primary

and secondary terms. Additionally, relay displays status of binary input, binary output and trip

counter for over current and earth fault trip.

During service, the default view of display shows three phase current and the earth current in

secondary terms. The values measured can be accessed using on the local HMI.

Event log 

To collect sequence – of – events (SoE) information,

the relay incorporates a non-volatile memory with a capacity of storing 250 events

with associated time stamps with resolution of 1 ms.

Event log includes protection operation status, binary I/O status and relay fault code.

The event logs are stored sequentially,the most recent being first and so on.

The non-volatile memory retains its data also in case the relay temporarily loses its auxiliary supply.

The event log facilitates detailed post-fault analysis of feeder faults and disturbances.

The SoE information can be accessed locally via the user interface on the relay front panel.