Sel 411L - Figure 3.144 Time-Overcurrent Logic

P.3.210
SEL-411L Relay Protection Manual Date Code 20151029
Protection Functions
Selectable Time-Overcurrent Elements (51)
If the calculated pickup value is greater than 3.2, the relay logic clamps the
pickup value at 3.2. Similarly, if the value is less than 0.05, the relay logic
clamps the pickup value at 0.05. At the same time that it clamps the values to
these limits, the logic sets a limit bit (51MMxx) to indicate to the user that the
read-in value is outside the specified limits.
Logic
Figure 3.144 Time-Overcurrent Logic
Settings Description
Operating Quantity
The 51 elements are unassigned, so you can select the operating quantity from
many phase and sequence quantities, as Table 3.110 shows.
51Pxx
(Pickup)
51TDxx
(Time Dial)
51Txx
(Element Time Out)
51Rxx
(Element Reset)
Limit check
0
+
–
B1
B2
51 Programmable Time
Overcurrent Element
Limit check
A1
A2
51Oxx
(Operating Quantity)
51TCxx
(Torque Control)
51Sxx
(Element Pickup)
SI
51TMxx (Time Dial Limits Exceeded)
51MMxx (Pickup Limits Exceeded)
Operating Quantity
51RSxx
(EM Reset)
Where: xx = 01–10
Table 3.110 Time-Overcurrent Operating Quantity List (Sheet 1 of 2)
Analog Quantity Description
LIAFIM Filtered instantaneous A-phase current magnitude
LIBFIM Filtered instantaneous B-phase current magnitude
LICFIM Filtered instantaneous C-phase current magnitude
B1IAFIM Filtered instantaneous Breaker 1 A-phase current magnitude
B1IBFIM Filtered instantaneous Breaker 1 B-phase current magnitude
B1ICFIM Filtered instantaneous Breaker 1 C-phase current magnitude
B2IAFIM Filtered instantaneous Breaker 2 A-phase current magnitude
B2IBFIM Filtered instantaneous Breaker 2 B-phase current magnitude
B2ICFIM Filtered instantaneous Breaker 2 C-phase current magnitude
LI1FIM Positive-sequence instantaneous current magnitude
L3I2FIM Negative-sequence instantaneous current magnitude
LIGFIM Zero-sequence instantaneous current magnitude
B1IGFIM Breaker 1 zero-sequence instantaneous current magnitude
B2IGFIM Breaker 2 zero-sequence instantaneous current magnitude
LIMAXM Filtered instantaneous maximum phase Current magnitude