Sel 411L - Figure 3.38 Extended Security Switchover Logic for the Alpha Plane Settings; Table 3.25 Extended Security Alpha Plane Switchover Logic Relay Word Bits

P.3.67
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
87L Differential Elements
Figure 3.38 Extended Security Switchover Logic for the Alpha Plane Settings
Table 3.25 lists the extended security Alpha Plane switchover logic Relay Word bits.
Open CT Detection Logic
Through use of the Open CT detection logic, you can identify problems with local or
remote current transformers (opened or shorted), wiring, test switches, or relay
current inputs. This logic applies differential measurements, but it is not integrated
with the differential elements. By default, the logic neither blocks nor otherwise
controls the 87L elements. This is to accommodate various application philosophies
related to alarming and tripping on open CT conditions.
Test Mode Variable
87TESTS = S
Relay Word Bits
87TEST
87CCU
87SYNL
87EFD
E87LPS
Test Mode Variable
87TESTS = S
Relay Word Bits
87TEST
87CCU
87SYNL
87EFD
E87LQS
Test Mode Variable
87TESTS = S
Relay Word Bits
87TEST
87CCU
87SYNL
87EFD
E87LGS
87LPSEC
87LQSEC
87LGSEC
1 cyc
2 cyc
1 cyc
2 cyc
1 cyc
2 cyc
Table 3.25 Extended Security Alpha Plane Switchover Logic Relay Word
Bits
Name Description
E87LPS User-programmable condition asserted to switch to extended security
87LP Alpha Plane settings
E87LQS User-programmable condition asserted to switch to extended security
87LQ Alpha Plane settings
E87LGS User-programmable condition asserted to switch to extended security
87LG Alpha Plane settings
87LPSEC 87LP element in the extended security Alpha Plane settings mode
87LQSEC 87LQ element in the extended security Alpha Plane settings mode
87LGSEC 87LG element in the extended security Alpha Plane settings mode