EQUATION1524 V4 EN-US (Equation 41)
The voltage thresholds UPh> is used to identify low voltage condition in the
system. Set UPh> below the minimum operating voltage that might occur during
emergency conditions. A setting of approximately 70% of UBase is recommended.
The current threshold IPh> shall be set lower than the IMinOp for the distance
protection function. A 5...10% lower value is recommended.
9.1.3.6 Dead line detection
M13683-78 v4
The condition for operation of the dead line detection is set by the parameters
IDLD< for the current threshold and UDLD< for the voltage threshold.
Set the IDLD< with a sufficient margin below the minimum expected load current.
A safety margin of at least 15-20% is recommended. The operate value must
however exceed the maximum charging current of an overhead line, when only one
phase is disconnected (mutual coupling to the other phases).
Set the UDLD< with a sufficient margin below the minimum expected operating
voltage. A safety margin of at least 15% is recommended.
1MRK 505 388-UEN B Section 9
Secondary system supervision
Busbar protection REB650 2.2 IEC 149
Application manual