Woodward HighPROtec MCDLV4, Manual, Page: 677 / 1275

Protective Elements
I - Overcurrent Protection [50, 51,51Q, 51V, 67]
Available stages:
I[1] ,I[2] ,I[3] ,I[4] ,I[5] ,I[6]
If you are using inrush blockings the tripping delay of the current protection
functions must be at least 30ms or more in order to prevent faulty trippings.
In order to ensure correct functioning of the directional detection after single-
phase short-circuits, the following reference voltage is used: For phase current
I1 it is the line-to-line voltage U23, for phase current I2 the line-to-line voltage
U31 and for phase current I3 the line-to-line voltage U12.
In case the fault happens to be near the measuring location and there is no
reference voltage for directional recognition available any more (neither
measured or from history (voltage memory)), then the module will - depending
on the parameter setting - either trip non-directional or it will be blocked.
All overcurrent protective elements are identically structured.
This module offers Adaptive Parameter Sets.
Parameters can be modified within parameter sets dynamically by means of
Adaptive Parameter Sets.
Please refer to chapter Parameter / Adaptive Parameter Sets.
677 MCDLV4 DOK-HB-MCDLV4-2E