R.3.37
Date Code 20111215 Reference Manual SEL-421 Relay
SELOGIC Control Equation Programming
SEL-311 and SEL-351 Series Users
In the SEL-311 series relays, SELOGIC control equation variables and timers
are connected. Each SEL
OGIC control equation variable is the input to a timer.
In the SEL-421, timers and SEL
OGIC control equation variables are
independent.
The SEL
OGIC control equation Boolean operators in the SEL-421 are different
from those used in SEL-300 series relays. For example, if you wish to convert
programming from an SEL-311 or SEL-351 series relay for the SEL-421, you
must convert the operators. Example 3.24 and Example 3.25 demonstrate
conversion of several settings to the SEL-421 setting.
EXAMPLE 3.24 Converting SEL-311
Series Relay SEL
OGIC Control Equation Variables
If you have the following SEL
OGIC control equation in an SEL-311
series relay, convert it as shown below.
SV1 = IN101 + RB3 * LT4
In the SEL-421, use the line shown below.
PSV01 := IN101 OR RB03 AND PLT04 # Free-form example .
In the example above, first convert the + and * operators in the
expression to the OR and AND operators. In the free-form example,
use a protection SEL
OGIC control equation variable for the result. In
the protection group settings example, use the input of a timer, as
shown in Table 3.2 5.
EXAMPLE 3.25 Converting SEL-311
Series Relay SEL
OGIC Control Equation Timers
If you have the following SEL
OGIC control equation timer in an SEL-311
series relay, convert it as shown below.
SV1 = IN101
SV1PU = 5.25
SV1DO = 3.5
OUT101 = SV1T
In the SEL-421, use the format shown below.
#
# Free-form programming conversion of timer
#
PCT01PU := 5.25 # Pickup of 5.25 cycles
PCT01DO := 3.5 # Dropout of 3.5 cycles
PCT01IN := IN101 # Use the timer to monitor IN101
In the output settings, set OUT101 as shown below:
OUT101 := PCT01Q
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