Sel SEL-421 - Conditioning Timer with Dropout and no Pickup Timing Diagram; Conditioning Timer with Pickup and Dropout Timing Diagram

R.3.19
Date Code 20111215 Reference Manual SEL-421 Relay
SELOGIC Control Equation Programming
SELOGIC Control Equation Elements
Figure 3.5 Conditioning Timer With Dropout and No Pickup Timing Diagram
Combining the features shown above, Figure 3.6 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 3.6 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 SEL-421, the protection processing interval is
1/8 cycle. Actual settings, programming, and operation are illustrated in
Example 3.7.
PCT02IN
PCT02Q
Input Changes
from 0 to 1
Input Changes
from 1 to 0
Dropout Time
Expires
Dropout Time
PCT02DO
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