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The shield ust only earthed the circuit-breaker the supply-side relay (ZSI side). 13. 11.2.
A
The axim length cable for zone selectivity, between units, 300 meters.
13.2.
The ZSO output can connected maximum ZSI relays the supply side the selectivity chain.
Model L2234 Apparatus Scale
L 2778
Doc.
13.3 Protection "I"
The protection enabled/disabled from the menu.
The following logical table implemented manage the Zone Selectivity Input (ZSI) and Zone Selectivity Output (ZSO) signals:
Z one tiv ity Imax ZSI ZSO signal rip T
Excluded trip
Excluded trip
Excluded YES programmed
Excluded YES programmed
Inserted trip
Inserted trip
Inserted YES 1
Inserted YES programmed
The time t2must set value higher than equal tselectivity +50ms, the the supply side, not required the first one the chain.
Operation only guaranteed when there auxiliary voltage.n remain operational.2.The zone selectivity function, guaranteed only auxiliary voltage provided, enables the area the fault isolated, only isolating the part
of plant nearest the fault, while keeping the rest the plant operational. 2
Page No.3 Zone selectivity "S"
As practical example, the figure above shows fault the load side the "Relay 1a" isolated the latter without the "Relay the "Relay
0" being affected; fault immediately downstream from the "Relay will isolated the latter without the "Relay being affected, thus ensuring
that the Areas 2.. the wiring has been done correctly, all the zone
selectivity inputs the last circuit-breakers the chain and all the outputs the circuit-breakers the head each chain must empty. Mo.2.
This function can activated through hand-held PR010/T unit via SD-Testbus2 and SD-Pocket softwares through remote system via system
bus.
13.9.
NB: Time expressed seconds.5 Protection "G"
This protection can disabled; can the fixed time (t=k) inverse time (t= k/i2) type; the latter case, the trip time given the expression:
' where If/I4 the fault current and the protection threshold.9.9.
The function can enabled from the menu the protection "I" page.1 Start-up threshold "I"
The start-up function can selected.2.2).9.9.9.3.2.2.
The function behaves exactly the same way the protection "S" (see par.
46/158
.2).
Use corded shielded o-w ire cable (see note par.9.. This function has one fixed-time protection curve only.
This protection goes when the closed, within time window ranging from 500ms and with threshold set customer, using
the same algorithm protection This protection can disabled and alternative protection "I".
13.
In the case where zone selectivity "S" active, during the trip the relay for "I", the ZSO output signal activated any case guarantee correct
operation the relay the supply side.
13.
This done connecting all the zone selectivity outputs the releases belonging the same zone one another (ZSO K51/SZout) and taking
this signal the zone selectivity input (ZSI K51/SZin) the next release the supply side.2.4 Protection against closing short-circuit
The MCR function used protect the system against closing, any, short-circuit, and operates only when Vaux PR120/V installed.
A
It ssib isa the trip tro the ctio ("Enable rip: Off").
For tio rth lt, irc it-b alarm
co itio sig ("A larm LED lit and alarm essage)