GE MiCOM P40 Agile - Page 299

Partial cross polarisation is therefore substituted for the normal memory polarising, for the duration of the TOC
Delay. If insufficient polarising voltage is available, a slight reverse offset (approximately 10% of the forward reach)
is included in the Zone 1 characteristic to enable fast clearance of close up three-phase faults.
P543i/P545i Chapter 9 - Non-Aided Schemes
P54x1i-TM-EN-1 263