Voltage Protection: Negative Phase Sequence Overvoltage (47) - 7Pg2114/6; Figure 4.9-1 Logic Diagram: Nps Overvoltage Protection (47) - Siemens Solkor 7PG2113 Technical Manual

4.9 Voltage Protection: Negative Phase Sequence
Overvoltage (47) – 7PG2114/6
Negative phase sequence (NPS) voltage (V2) is a measure of the quantity of unbalanced voltage in the system.
The relay derives the NPS voltage from the three input voltages (VL1, VL2 and VL3).
Two elements are provided 47-1 & 47-2.
47-n Setting sets the pick-up voltage level for the element.
The 47-n Hysteresis setting allows the user to vary the pick-up/drop-off ratio for the element.
An output is given after elapse of the 47-n Delay setting.
Operation of the negative phase sequence voltage elements can be inhibited from:
Inhibit 47-n
47-n Element
Enabled
Disabled
Inhibit 47-n
VL1
VL2
VL3
©2010 Siemens Protection Devices Limited
A binary or virtual input.
47-n Setting
&
47-n Hysteresis
c
>
V2
NPS
Filter

Figure 4.9-1 Logic Diagram: NPS Overvoltage Protection (47)

7PG2113/4/5/6 Solkor Description of Operation
General Pickup
47-n Delay
47-n
Chapter 1 Page 56 of 80