Functions
282
7UM62 Manual
C53000-G1176-C149-3
2.44.2 Processing Tripping Logic
2.44.2.1 Functional Description
General trip
The tripping signals for all protective functions are connected by ”OR” and generate a
message ”
General TRIP
” indicating that the device has initiated a trip signal.
This annunciation, like individual trip indications, can be allocated to an LED or an
output relay. It can also be used as a sum event.
Terminating the
Tripping Signal
•
If a protective function is set to
Block Relay
, it is blocked for the activation of the
output relay. The other protective functions are not affected by this.
•
A trip command once transmitted is stored (see Figure 2-131). At the same time,
the minimum trip command duration
is started. This trip signal
duration timer ensures the trip signal 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 signal is only terminated after all protection Functions drop out AND
the minimum trip signal duration expires.
•
Finally, it is possible to latch the trip signal until it is manually reset (lockout
function). This allows to lock the circuit breaker against reclosing until the cause of
the malfunction has been clarified and the lockout has been manually reset. The
reset takes place either by pressing the LED reset key or by activating an
appropriately masked binary input (”
”). A precondition, of course, is
that the circuit breaker trip coil – as usual – remains energized at the circuit breaker
as long as the trip signal is present, and that the trip coil current is interrupted by the
auxiliary contacts of the circuit breaker.
Figure 2-131 Terminating the Trip Signal, Example of a Protective Function
2.44.2.2 Settings for the Tripping Logic
Trip and Close
Command Duration
The setting of the minimum trip signal duration at address
was already discussed in Subsection 2.3. This time is valid for all protective functions
T
S
R
Q
&
Tripping, e.g. I>
S
R
Q
Lockout function
(Output relay stored)
Lockout reset
(using LED–Reset)
Block.Relais
, e.g. I>
&
Relay
triggering
