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2.2 easuring Function
A current measuring function (ammeter) available all versions the PR121/P unit. This function can activated through PR010/T test unit.n°. Any anomalies are indicated the LED coming on, explained par. 98% with condensation
IP 30
Model L2234 Apparatus Scale
L 2778
Doc.
For the inverse-time protections, the relationship between trip time and overcurrent given the formula: /I2.
With auxiliary voltage, the protection records historical the maximum current read.: Beyond 15..B. 2
Page No.
If the waveform has deformation beyond the declared limit (6.
For the fixed-time protections with adjustable delay, the relationship adopted follows: k.. +90°C
0% .
12. 12..2.
The PR121/P unit allows the neutral pole's current signal beprocessed using different relationships with the value the phases. protectionagainst instantaneous short-circuit high currents "Iinst".2..
The characteristics the power pack are given the table below. 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.7. protection against overload with inverse time "L";
2.
The unit also has "backup protection" function.5.
N. +70°C
-40°C .
12.
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.
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..4 unication bus
Local bus rear connector; RS485 physical interface, Modbus protocol.
□ atchdog for proper current sensor connection (CS).e.1.
12.5xIn current the Ne, the protection considered being set 100%.
□ atchdog for proper opening solenoid connection (TC).The presence the auxiliary power supply enables the relay unit used even with the circuit-breaker open.3 atchdog
The PR121/P unit provides some watchdog functions guarantee the proper management relay malfunctions. 12.3@2In), the tolerance for the calculation the true rms value will increase.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.. protection against short-circuit with adjustable delay "S";
3.
-25°C . protectionagainst earth fault with adjustable delay "G";
5.5In< I4<0.8In] and greater than 4In [where I4<0,5In].7.
32/158
.
This function can accessed through PR10/T test unit only via test bus and through HMI030 via local bus.
12. These functions are follows:
□ Rating PLUG validity.2. Ifthe sensors are disconnected there Rating Plug error, when activated, opening command
is issued due the being activated.2.:
1.5. Any anomalies are indicated the LED coming on, explained par.1.5.5 Protection functions
The PR121/P unit provides independent protection functions, i.
Test bus front test connector.
□ atchdog for protection against Trip. protectionagainst instantaneous short-circuit "I";
4
