ERL L-PRO 4000, User Manual

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4 Protection Functions and Specifications
D02706R02.30 L-PRO 4000 User Manual 4-51
PUTT Logic
The PUTT logic is used for tripping schemes where the local end under-reach
the remote end for close in forward fault conditions, for details see Figure 4.27:
Communication-aided Scheme on page 4-48. The local end sends a permissive
trip signal to the remote end when one of the forward directional elements op-
erates (Zone 1 distance elements). The scheme send signal (permissive transfer
trip send) is time delayed by timer setting TL3, the local end is required to
sense a forward fault for durations greater than TL3. The remote end does not
produce a scheme trip output unless a forward directional fault is detected and
the local end has sent the permissive trip signal. The remote end senses a per-
missive trip receive signal and the scheme trip closes the output contacts and
removes the fault contribution from the remote end. The remote end can act
quicker for fault conditions where the Zone 2 faults would be time delayed un-
less the close in fault condition was not transferred by the scheme send.
4.2 Recording Functions
Introduction
The relay has high speed fault recording and logging functions to allow the
user to analyze faults and to review the operation of the overall protection
scheme. Slow speed swing recording can be used to analyze system stability.
If the relay has reached its recording capacity, new records overwrite the oldest
records.
Fault Recording
The relay provides DFR-quality fault recording, capturing input signal wave-
forms and external input states at a rate of 96 samples per cycle. Each record
also contains the timing of the internal logic produced by the relay (e.g. Device
51 trip). Obtain this information by uploading the records from the relay via
the Relay Control Panel file transfer process and view them with RecordBase
View software.
The quantities recorded are:
• 18 analog channels (6 voltages and 12 currents) @ 96 samples/cycle which
captures up to the 25th harmonic
• External inputs @ 1 ms resolution
• Protection element output signals @ 8 samples/cycle
• ProLogic signals @ 8 samples/cycle
• Active setting group
Parameters that are user-selectable with respect to recording transients:
• Record length (0.2 to 10.0 seconds => 12 to 600 cycles @ 60 Hz Base) with
automatic extension to capture successive triggers
• Recorder triggering by any internal logic or external input signal (e.g. 52 A)
• Pre trigger time configurable between 0.10 to 2.00 seconds