Figure 3-29 Logic Diagram: Neutral Overvoltage Element (59N) - Siemens 7SR12 Argus Manual

7SR11 & 7SR12 Description Of Operation
It should be noted that neutral voltage displacement can only be applied to VT arrangements that allow zero
sequence flux to flow in the core i.e. a 5-limb VT or 3 single phase VTs. The VT primary winding neutral must be
earthed to allow the flow of zero sequence current.
59NIT Element
Disabled
Enabled
Inhibit 59IT
VL1
ZPS
Filter
VL2
VL3
59NDT Element
Disabled
Enabled
Inhibit 59NDT
Figure 3-29
Chapter 1 Page 56 of 88
59NIT Setting
59NIT Charact
59NIT Time Mult
59NIT Delay (DTL)
&
59NIT Reset
c
3Vo
59NDT Setting
&
c
Logic Diagram: Neutral Overvoltage Element (59N)
Pickup
trip
59NDT Delay
>
©2017 Siemens Protection Devices Limited
General Pickup
59NIT
General Pickup
59NDT