Schweitzer Engineering SEL-351P - Directional Control Provided by Torque Control Settings

Date Code 990430 Loss-of-Potential, Load Encroachment, and Directional Element Logic 4-35
SEL-351P Manual Técnico
directional elements, SEL OGIC Control Equation setting E32IV should be deasserted to logical 0.
In this example, this is accomplished by connecting a circuit breaker auxiliary contact from the
identified circuit breaker to the SEL-351P:
E32IV = IN106 (52a connected to optoisolated input IN106)
Almost any desired control can be set in SEL
OGIC Control Equation setting E32IV.
D IRECTIONAL C ONTROL P ROVIDED BY T ORQUE C ONTROL S ETTINGS
For most applications, the level direction settings DIR1 through DIR4 are used to set overcurrent
elements direction forward, reverse, or nondirectional.
Table SECTION 4: .1 shows the
overcurrent elements that are controlled by each level direction setting. Note in
Table SECTION
4: .1 that all the time-overcurrent elements (51_T elements) are controlled by the DIR1 level
direction setting. See
Figure SECTION 4: .14, Figure SECTION 4: .15, Figure SECTION 4:
.20, and
Figure SECTION 4: .21.
In most communications-assisted trip schemes, the levels are set as follows (see Figure 5.4):
Level 1 overcurrent elements set direction forward (DIR1 = F)
Level 2 overcurrent elements set direction forward (DIR2 = F)
Level 3 overcurrent elements set direction reverse (DIR3 = R)
Suppose that the Level 1 overcurrent elements should be set as follows:
67P1 direction forward
67G1 direction forward
51P1T direction forward
51P2T direction reverse
51N1T nondirectional
51G1T direction forward
To accomplish this, the DIR1 setting is “turned off,” and the corresponding SEL
OGIC Control
Equation torque control settings for the above overcurrent elements are used to make the
elements directional (forward or reverse) or nondirectional. The required settings are:
DIR1 = N (“turned off”; see
Figure SECTION 4: .14, Figure SECTION 4:
.15,
Figure SECTION 4: .20, and Figure SECTION 4: .21)
67P1TC = 32PF (direction forward; see Figure 3.3)
67G1TC = 32GF (direction forward; see Figure 3.10)
51P1TC = 32PF (direction forward; see Figure 3.14)
51P2TC = 32PR (direction reverse; see Figure 3.15)
51N1TC = 1 (nondirectional; see Figure 3.16)
51G1TC = 32GF (direction forward; see Figure 3.18)
This is just one example of using SEL
OGIC Control Equation torque control settings to make
overcurrent elements directional (forward or reverse) or nondirectional. This example discussed
only Level 1 overcurrent elements (controlled by level direction setting DIR1). The same setting
principles can apply to the other levels as well. Many variations are possible.