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N.5 Protection functions
The PR121/P unit provides independent protection functions, i.: Beyond 15.
12.
-25°C .. 12.
□ atchdog for proper opening solenoid connection (TC). protectionagainst earth fault with adjustable delay "G";
5. protectionagainst instantaneous short-circuit "I";
4. This function can activated through PR010/T test unit.
12.
The unit also has "backup protection" function.
The PR121/P unit allows the neutral pole's current signal beprocessed using different relationships with the value the phases.5xIn current the Ne, the protection considered being set 100%.2.5.
With auxiliary voltage, the protection records historical the maximum current read. These functions are follows:
□ Rating PLUG validity. Any anomalies are indicated the LED coming on, explained par.
12.2.
For the inverse-time protections, the relationship between trip time and overcurrent given the formula: /I2. 2
Page No.
A timing indication ("alarm" LED) provided the front the unit, which enabled during alarm for each protection; disabled when the
alarm condition ceases when the protection has been tripped... Any anomalies are indicated the LED coming on, explained par...
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.5.4 unication bus
Local bus rear connector; RS485 physical interface, Modbus protocol.2.n°. 98% with condensation
IP 30
Model L2234 Apparatus Scale
L 2778
Doc. protection against short-circuit with adjustable delay "S";
3.1.3@2In), the tolerance for the calculation the true rms value will increase.7. +90°C
0% .:
1.
The characteristics the power pack are given the table below.The presence the auxiliary power supply enables the relay unit used even with the circuit-breaker open.8In] and greater than 4In [where I4<0,5In]. the circuit-breaker does not open immediately the first time the Trip Coil hit (partial failure),
TRIP commands are sent repeatedly until the circuit-breaker opens.2.
This function can accessed through PR10/T test unit only via test bus and through HMI030 via local bus.2.1..
C ris tic 121/P
Auxiliary voltage
(galvanically separated) 24V ±20%
Maximum ripple 5%
Inrush current 24V ~10A for ms
Rated power 24V ~2W
1 iro ris tic s
Operating temperature
Storage temperature
Relative humidity
Degree protection (with PR121/P installed the circuit-breaker)
12.1 Calculating the RMS
All the protection functions their respective processing the basis the real rms value the currents (the protection disabled for current
values greater than 8In [where I4>0,8In], greater than 6In [where 0.3 atchdog
The PR121/P unit provides some watchdog functions guarantee the proper management relay malfunctions. protectionagainst instantaneous short-circuit high currents "Iinst". Ifthe sensors are disconnected there Rating Plug error, when activated, opening command
is issued due the being activated.B.
For the fixed-time protections with adjustable delay, the relationship adopted follows: k.
If the waveform has deformation beyond the declared limit (6. protection against overload with inverse time "L";
2.5.
Test bus front test connector.
□ atchdog for proper current sensor connection (CS).2 easuring Function
A current measuring function (ammeter) available all versions the PR121/P unit.5In< I4<0.7. +70°C
-40°C . 12.
□ atchdog for protection against Trip.e.
12
