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There sensor inside the PR123/P unit that monitors the temperature the unit.Na 2
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It indispensable for the star center connected openly earth and for not used neutral conductor too(as inthe TNC system),
making protection according the system.B.
The behavior and wiring the function are identical those indicated for zone selectivity "S" (see par.
The function can enabled and disabled the protection "G" page.
The induced current the winding the toroid proportional the fault current which, this case, only transits the above-mentioned toroid.
The function behaves exactly the same way the protection "S" (see par.8 Protection against phase unbalance "
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 I6.2.
W hen the value the phase rre above 6xIn, the ctio "U" xcludes its because, iscase, the
o tio rve because the sid phase fault.2..In the latter case, the trip time given the expression
j where If/I4 the fault current and the protection threshold.100 where the maximum and the minimum phase current.
A
The external toroid ust connected the PR123/P means corded shielded o-w ire cable (see note par.
14.: can used also with for external neutral. 14.. 85°C the display turned off and
State "ALARM TEMPERATURE" with temp.
14.) which has star-configured windings.2.
-25°C temp.
The protections and Gext can enabled simultaneously.tio "
This protection can disabled; can the fixed time (t=k) inverse time (t= k/i2) type.9. Trip On" parameter).1 Start-up threshold "G"
The start-up function can selected the case where the curve with fixed time selected.2.2.7.3xIn.3).9.
The protection not enabled for axim phase current values lower than 0.9. This operating mode enabled default. -20°C 70°C temp.2).9.
Zone selectivity "G" can active the same time zone selectivity "S".
The percentage unbalance therefore calculated _E22-ehl .
The shield ust earthed both the circuit-breaker side and the toroid side.
A
it ssib isa the trip tro the ctio ("Enable rip: Off").
N. Range: .
or
Model 2234 Apparatus Scale
L2778
Doc.2.
in case, the hole duration the unbalance the ill not opened,but only the itio ill be
sig eans the arning" LED lit and rning essage.
For the hole duration the earth fault, circuit-breaker opening does not take place, but only the alarm condition signaled
("Alarm" LED lit and alarm message).2)
w ith not exce ding 15m. 14.
I .
NB: Time expressed seconds.
To work this mode, "Ground protection" must selected the Circuit-breaker Settings menu.
This enables the signalling any abnormal temperature conditions, which could cause temporary continuous malfunctions the unit's electronic
components. 11.2 Zone selectivity "
The zone selectivity function can enabled providing the fixed time curve, the wiring and the zone selectivity "G" enabling alternative the one for
"D" have been selected and the function assured only auxiliary voltage provided. The fault current defined the following formula:
I n
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.1x In(where Inisthe
rated current the hom opolar toroidal transformer; the settings available are 100, 250, 400, 800A). 85°C the display turned off,
the "WARNING" and "ALARM" leds flash 2Hz and Trip activated (if enabled means the "Over Temper.2.2.
This protection has two states operation:
State "WARNING TEMPERATURE" with
the "WARNING" LED flashes 0.
P rotection with external "Source round eturn"
Also called "Source Ground return", this can carried out when there the need check operation machine (transformer, generatoror
motor etc.
The PR123/P unit can provide two different types earth fault protection, sim ultaneously:
In ctio G
This provided inside the release vectorially summing the phase and neutral currents.7.1 max min 1
A
it ssib isa the trip tro the ctio ("Enable rip: Off").The minimum allowable threshold for the Gext protection 0.
The protection assured physically positioning external toroid the cable connected from the star center the machine the earthing
connection point.
14.9. 90% steps.5Hz. -25°C temp
