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.B.2. The fault current defined the following
formula: _
^ la
In the case when the circuit does not show any fault, the module the sum these currents always nil; vice versa the value the fault current
will take increasingly large value depending the size the fault. This operating mode enabled default.2.2.
13.
The function can enabled and disabled the protection "G" page.
This protection has two states operation:
State “WARNING TEMPERATURE” with
the "WARNING" LED flashes 0.
Zone selectivity "G" can active the same time zone selectivity "S".
53/108
.9.
13.3xIn.
The percentage unbalance therefore calculated ------— 100 where the maximum and the minimum phase current.6. 13.2.
A Disabling the Trip control the protection means that the PR123/DC unit could work, with the circuit-breaker closed, a
range temperatures where correct operation the electronics not guaranteed.
The protection always active, both with auxiliary supply and self-powering.
13.3).2.
max
or
or
Model 3447
Apparatus Emax DC
Scale
D 1SDH000635R0002
Page No.9.
This provided inside the release calculating the vectorial sum the currents the two polarities. -25°C temp. 13.6.
I . 85°C
: the display turned off and
: the display turned off,
the "WARNING" and “ALARM” leds flash 2Hz and Trip activated (if enabled means the "Over Temper.9.8 Protection against overtemperature inside the relay “OT”
There sensor inside the PR123/DC unit that monitors the temperature the unit. Range: .9.
The protection not enabled for maximum phase current values lower than 0. 85°C
temp.
A
It possible disable the trip control the protection ("Enable Trip: Off").
■ The monitored temperature not visible the display. the latter case, the trip time given the expression
- 2max where If/I4 the fault current and the protection threshold.9.9.13.2.6 Protection “G”
This protection can disabled; can the fixed time (t=k) inverse time (t= k/i2) type.2.
The function behaves exactly the same way the protection "S" (see par.5Hz. 90% steps.
NB: Time expressed seconds.2 Zone selectivity “G”
The zone selectivity function can enabled providing the fixed time curve, and the function assured only auxiliary voltage provided.~ max min ~
A possible disable the trip control the protection ("Enable Trip: Off"). Trip On" parameter).
When the value the phase current above 6xIn, the function "U" excludes itself because, thiscase, the
other protections intervene because the fault considered phase fault.
This enables the signalling any abnormal temperature conditions, which could cause temporary continuous malfunctions the unit's electronic
components.:
■ the event Warning and Alarm, the display momentarily turned off, preserve its functionality.
13. -20°C 70°C temp.2).9.
For the whole duration the earth fault, circuit-breaker opening does not take place, but only the alarm condition signaled
("Alarm" LED lit and alarm message).
N.
State “ALARM TEMPERATURE” with
-25°C temp.
In that case, for the whole duration the unbalance the will not opened, but only the conditionwill be
signaled means the "warning" LED lit and warning message.2.1 Start-up threshold “G”
The start-up function can selected the case where the curve with fixed time selected.
The behavior and wiring the function are identical those indicated for zone selectivity "S" (see par.2..7 Protection against phase unbalance “U”
The protection with fixed time, which can excluded, trips the case when, for time greater than the same the time set, unbalance
is determined between two more phases higher than the set threshold I6
