more of the IEDs binary outputs, as well as to other functions within the IED requiring
this signal.
AND
BLOCK
TRIN
Operation Mode
=
Enabled
OR
t
tTripMin
TRIP
Program
= 3 phase
ANSI10000266-1-en.vsd
ANSI10000266 V1 EN
Figure 427: Simplified logic diagram for three pole trip
SMPPTRC (94) function for single-pole and two-pole tripping has additional phase
segregated inputs for this, as well as inputs for faulted phase selection. The latter inputs
enable single- pole and two-pole tripping for those functions which do not have their
own phase selection capability, and therefore which have just a single trip output and
not phase segregated trip outputs for routing through the phase segregated trip inputs of
the expanded SMPPTRC (94) function. Examples of such protection functions are the
residual overcurrent protections. The expanded SMPPTRC (94) function has two
inputs for these functions, one for impedance tripping (for example, carrier-aided
tripping commands from the scheme communication logic), and one for ground fault
tripping (for example, tripping output from a residual overcurrent protection).
Additional logic, including a timer tWaitForPHS, secures a three-phase trip command
for these protection functions in the absence of the required phase selection signals.
The expanded SMPPTRC (94) function has three trip outputs TR_A, TR_B, TR_C
(besides the trip output TRIP), one per phase, for connection to one or more of the
IEDs binary outputs, as well as to other functions within the IED requiring these
signals. There are also separate output signals indicating single-pole, two-pole or three-
pole trip. These signals are important for cooperation with the autorecloser SMBRREC
(79) function.
The expanded SMPPTRC (94) function is equipped with logic which secures correct
operation for evolving faults as well as for reclosing on to persistent faults. A special
input is also provided which disables single- pole and two-pole tripping, forcing all
tripping to be three-pole.
In multi-breaker arrangements, one SMPPTRC (94) function block is used for each
breaker. This can be the case if single pole tripping and autoreclosing is used.
Section 14 1MRK505222-UUS C
Logic
860
Technical reference manual
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