P.14.19
Date Code 20151029 Protection Manual SEL-411L Relay
SELOGIC Control Equation Programming
SEL
OGIC Control Equation Elements
Combining the features shown above, Figure 14.6 illustrates conditioning
timer operation for use of both the pickup and dropout characteristics. The
Output, PCT03Q, turns on after the Input, PCT03IN, turns on and the Pickup
Time, PCT03PU, expires. The Output turns off after the Input turns off and the
Dropout Time, PCT03DO, expires.
Figure 14.6 Conditioning Timer With Pickup and Dropout Timing Diagram
Set the conditioning timer settings for Pickup and Dropout in cycles and
fractions of a cycle (represented in decimal form). The relay processes
conditioning timers once for each protection processing interval. The relay
asserts the timer output on the first processing interval when the elapsed time
exceeds the setting. In the relay, the protection processing interval is 1/8 cycle.
Actual settings, programming, and operation are illustrated in Example 14.7.
EXAMPLE 14.7 Conditioning Timer Programming and Operation
This example uses Protection Free-Form Conditioning Timer Seven,
PCT07. The free-form settings are as shown here:
PCT07PU := 5.3 # Pickup set to 5.3 cycles
PCT07D0 := 6.0 # Dropout set to 6.0 cycles
PCT07IN := IN201 # Operate on the first input on the interface board
PSV29 := PCT07Q # Protection SEL
OGIC control equation variable follows the
timer output
The operation of the timer when IN201 turns on for 7 cycles is shown
in the timing diagram in Figure 14.7. Because the pickup setting is an
uneven number of protection processing intervals (1/8 cycle), the
pickup occurs on the first 1/8th cycle after the Pickup Time of 5.3
cycles expires.
Figure 14.7 Conditioning Timer Timing Diagram for Example 14.7
PCT03IN
PCT03Q
Input Changes
from 0 to 1
Input Changes
from 1 to 0
Dropout Time
Expires
Pickup Time
Expires
Dropout Time
PCT03DO
Pickup
Time
PCT03PU
IN201
PSV29
DropoutPickup
Dropout Time
Pickup
Time
5.375 Cycles
6.0 Cycles
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