2 Functions
406
7SD5 Manual
C53000-G1176-C169-1
General Trip All trip signals for the protective functions are connected by OR and generate the
message „Relay TRIP“. This can be allocated to LED or output relay.
Terminating the
Trip Signal
Once a trip command is initiated, it is phase segregatedly latched (in the event of
three-pole tripping for each of the three poles) (refer to Figure 2-178). At the same
time, the minimum trip command duration TMin TRIP CMD is started. This ensures
that the command is transmitted to the circuit breaker for a sufficient amount of time,
even if the function which issued the trip signal drops out quickly. The trip commands
can only be terminated when the last protection function dropped out (i.e. functions no
longer pick up) AND the minimum trip signal duration expired.
A further condition for the reset of the trip command is that the circuit breaker has
opened, in the event of single-pole tripping the relevant circuit breaker pole. In the
function control of the device, this is checked by means of the circuit breaker position
feedback (Section „Detection of the Circuit Breaker Position“) and the flow of current.
The residual current PoleOpenCurrent that is certainly undershot when the circuit
breaker pole is open is set in address 1130. Address 1135 Reset Trip CMD deter-
mines under which conditions a trip command is reset. If CurrentOpenPole is set,
the trip command is reset as soon as the current disappears. It is important that the
value set in address 1130 PoleOpenCurrent (see above) is undershot. If Current
AND CB is set, the circuit breaker auxiliary contact must send a message that the
circuit breaker is open. It is a prerequisite for this setting that the position of the auxil-
iary contacts is allocated via a binary input.
Figure 2-178 Storage and termination of the trip command
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