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12.
The function can enabled from the menu the protection "I" page.4 Protection “MCR” against closing short-circuit
The MCR function used protect the system against closing, any, short-circuit.. 11.2.9.3 Protection “I”
The protection enabled/disabled from the menu.2.B. -20 temp.
A Disabling the Trip control the protection means that the PR122/DC unit could work, with the circuit-breaker closed, a
range temperatures where correct operation the electronics not guaranteed.
A
The maximum length cable for zone selectivity, between two units, 300 meters.
This protection has two states operation:
State “WARNING TEMPERATURE” with
and the "WARNING" LED flashes 0.
Usecorded shielded two-wire cable (see note par.
■ The monitored temperature not visible the display.5 Protection against overtemperature inside the relay “OT”
There sensor inside the PR122/DC unit that monitors the temperature the unit.2)..
or
o r
Model 3447 Apparatus cale
d 1SDH000635R0002
Page No.9.n remain operational.2.
The ZSO outputcan connected maximum ZSI relays the supply side the selectivity chain.
This enables the signalling any abnormal temperature conditions, which could cause temporary continuous malfunctions the unit's electronic
components. °C
temp.
The shield must only earthed the circuit-breaker the supply-side relay (ZSI side).
The following logical table implemented manage the Zone Selectivity Input (ZSI) and Zone Selectivity Output (ZSO) signals:
Zone selectivity Imax ZSI signal ZSO signal Trip 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.
The protection always active, both with auxiliary supply and self-supply.2). Trip On" parameter)
N.
12.9.:
■ the event Warning and Alarm, the display turned off, preserve its functionality.2.
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”.
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. °C
the display turned off
: the display turned off,
the "WARNING" and “ALARM” Leds flash 2Hz and the Trip activated (if enabled means the "Over Temper.
The function behaves exactly the same way the protection "S" (see par. -25 temp.3.5Hz
State “ALARM TEMPERATURE” with
-25 temp.2.
This function can activated through hand-held PR010/T unit via SD-Testbus2 and SD-Pocket softwares through remote system via system
bus.
Operation only guaranteed when there auxiliary voltage.2. 12.9.1 Start-up threshold “I”
The start-up function can selected.
12. This function has one fixed-time protection curve only.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.
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.9.
12.2
