4 Protection settings
4.11 Event logging and waveform capture
32
PXR Electronic trip unit
01/21 MN012005EN
www.eaton.com
The ZSI function is connected to the interface module of the circuit breaker
via three wires, which are marked
•
Zone In (Z
in
),
•
Zone Out (Z
out
),
•
Zone Common (Z
com
).
These signals are compatible with all Eaton circuit breakers that have the ZSI
function. An output signal will be transmitted each time the ground-fault
threshold or the short-time delay threshold is exceeded. This provides
maximum selectivity for coordination with larger upstream circuit breakers.
Depending on the application, a self-locking jumper may be required for the
farthest upstream circuit breaker. If immediate tripping is desired on the last
circuit breaker, the Z
in
wire of that circuit breaker can be left open, while the
Z
out
wire then has to be connected to the Z
in
of the next upstream circuit
breaker. If a time delay is desired on the last circuit breaker, a jumper from
the Z
out
wire of that circuit breaker can be connected to the Z
in
wire of the
same breaker to provide for self-interlocking.
4.11 Event logging and waveform capture
The PXR trip unit records information about events, alarms and trips in
various logs. For “ordinary” events, only the reason and a time-stamp (based
on the trip unit’s real-time clock) will be stored. For more “complex” events,
the real-time values (currents and voltages) will additionally be stored. For the
most important events, additional information, such as the current and
voltage waveforms during the event, will also be stored.
Each log can store a specified number of events and is managed as a first-in-
first-out (FIFO) buffer. When saving the information of the most recent
event, the information of the oldest event will be deleted if the maximum
number of events for the respective log has been exceeded.
