Recorded data

The relay has the capacity to store the records of the 128 latest

fault events. The records can be used to analyze the power

system events. Each record includes, for example, current,

residual voltage and angle values, start times of the protection

blocks and a time stamp. The fault recording can be triggered

by the start or the trip signal of a protection block, or by both.

The available measurement modes include DFT, RMS and

peak-to-peak. Fault records store relay measurement values at

the moment when any protection function starts. In addition,

the maximum demand current with time stamp is separately

recorded. The records are stored in the nonvolatile memory.

Trip circuit supervision

The trip circuit supervision continuously monitors the availability

and operation of the trip circuit. It provides two open-circuit

monitoring functions that can be used to monitor the circuit

breaker’s control signal circuits. It also detects loss of circuit

breaker control voltage.