Schweitzer Engineering SEL-351P, Quick Start Manual

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5-2 Trip and Target Logic Date Code 990215
SEL-351P Manual Técnico
range for this timer is 4 - 16,000 cycles. See Figure SECTION 5: .2.
More than one trip setting (or all four trip settings TRCOMM, DTT, TRSOTF, and TR) can be
set. For example, in a communications-assisted trip scheme, TRCOMM is set with direction
forward overreaching Level 2 overcurrent elements, TR is set with direction forward
underreaching Level 1 overcurrent elements and other time delayed elements (e.g., Level 2
definite-time overcurrent elements), and TRSOTF is set with nondirectional overcurrent
elements.
Figure SECTION 5: .1: Trip Logic
The TRIP Relay Word bit output of the trip logic in Figure SECTION 5: .1 propagates to the
final trip/close logic in Figure 7.29 . The logic in Figure 7.29 controls dedicated trip and close
output contacts and prevents the trip and close output contacts from being asserted at the same
time.