Seg MRD1-T, Manual

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18 TB MRD1-T 10.01 E
4.6.6 Parametrizing blocking
Blocking of protective function
The MRD1 offers a configurable blocking function.
When applying a voltage to terminals D8-E8 all protec-
tive functions are blocked that are configured for block-
ing. In case of active blocking the output relays don’t
act, but the device shows the fictive trip by means of
Trip-LED.
A minimum hold time can be set for the blocking. During
this time, starting from the begin of external blocking, all
protective functions are blocked, also in case the exter-
nal blocking may was released. In case of longer con-
tinuous external blocking the blocking can be stopped
after a maximum hold time t
max
for enabling the relay to
trip in case of ongoing faults.
wirksame Blockierzeit
effective block. time
ext. Block. Eingang
ext. blockage input
t
min
t
t
max
!
Note:
Repeated impulse at the blocking time within tmin restart
the hold times.
Assignment of functions to output relays
The MRD1 offers 5 output relays. Relay number 5 is
preassigned to the selftest function of the relay and is
working with zero-signal current principle. Output relays
1 – 4, and 6 – 10 are open-circuit relays and can be
assigned to internal logic functions.