Current protection

Instantaneous phase overcurrent protection (PIOC, 50)

The instantaneous three phase overcurrent function has a low transient overreach and short tripping

time to allow use as a high set short-circuit protection function, with the reach limited to less than

typical eighty percent of the power line at minimum source impedance.

Four step phase overcurrent protection (POCM, 51_67)

The four step phase overcurrent function has an inverse or definite time delay independent for each

step separately.

The single input overcurrent function has a low transient overreach and short tripping times to

allow use as a high set short circuit protection function, with the reach limited to less than typical

eighty percent of the power line at minimum source impedance. The function can be configured

to measure the residual current from the three phase current inputs or the current from a separate

current input.

Four step residual overcurrent protection (PEFM, 51N/67N)

The four step single input overcurrent function has an inverse or definite time delay independent for

each step separately.

All IEC and ANSI time delayed characteristics are available together with an optional user

defined characteristic.