7SR210 & 7SR220 Description of Operation
Unrestricted ©2018 Siemens Protection Devices Limited
Page 45 of 94
3.8
Current Protection: Negative Phase Sequence
Overcurrent (46NPS)
The negative sequence phase (NPS) component of current (I2) is derived from the three phase currents. It is a
measure of the quantity of unbalanced current in the system.
Two NPS current elements are provided – 46IT and 46DT.
The 46IT element can be configured to be either definite time lag (DTL) or inverse definite minimum time (IDMT),
46IT Setting
sets the pick-up current level for the element.
A number of shaped characteristics are provided. An inverse definite minimum time (IDMT) characteristic is
selected from IEC and ANSI curves using
46IT Char
. A time multiplier is applied to the characteristic curves using
the
46IT Time Mult
setting. Alternatively, a definite time lag delay (DTL) can be chosen using
46ITChar
. When
Delay (DTL) is selected the time multiplier is not applied and the
46IT Delay (DTL)
setting is used instead.
The
46IT Reset
setting can apply a,
definite time delayed
or
ANSI (DECAYING)
reset.
The 46DT element has a DTL characteristic.
46DT Setting
sets the pick-up current and
46DT Delay
the follower
time delay.
Operation of the negative phase sequence overcurrent elements can be inhibited from:
Inhibit 46IT
A binary or virtual input, function key or remote data Comms
Inhibit 46DT
A binary or virtual input, function key or remote data Comms
Figure 3.8-1 Logic Diagram: Negative Phase Sequence Overcurrent (46NPS)
Summary of Contents for Argus 7SR21
Page 1: ...Energy Management 7SR21 7SR22 Argus Overcurrent Relay Reyrolle Protection Devices ...
Page 2: ......
Page 4: ...Contents 7SR11 and 7SR12 Page 2 of 2 2018 Siemens Protection Devices Limited ...
Page 185: ...7SR210 Settings Guide Unrestricted 2018 Siemens Protection Devices Limited Page 61 of 61 ...
Page 277: ...7SR220 Settings Guide Unrestricted Page 72 of 107 2013 Siemens Protection Devices Limited ...
Page 382: ...7SR220 Technical Manual Chapter 4 Page 2 of 96 2017 Siemens Protection Devices Limited ...
Page 386: ...7SR220 Technical Manual Chapter 4 Page 6 of 96 2017 Siemens Protection Devices Limited ...
Page 398: ...7SR220 Technical Manual Chapter 4 Page 18 of 96 2017 Siemens Protection Devices Limited ...
Page 414: ...7SR220 Technical Manual Chapter 4 Page 34 of 96 2017 Siemens Protection Devices Limited ...
Page 466: ...7SR220 Technical Manual Chapter 4 Page 86 of 96 2017 Siemens Protection Devices Limited ...
Page 468: ...7SR220 Technical Manual Chapter 4 Page 88 of 96 2017 Siemens Protection Devices Limited ...
Page 470: ...7SR220 Technical Manual Chapter 4 Page 90 of 96 2017 Siemens Protection Devices Limited ...
Page 472: ...7SR220 Technical Manual Chapter 4 Page 92 of 96 2017 Siemens Protection Devices Limited ...
Page 643: ...Unrestricted ...