Rockwell Automation 140G-NTK-E12 LSIG and LSIG-MM Release - Manual (Page 13)

DIR 1000587R0002 (L3821)
(13)
3.1.2.2 Auxiliary power supply
External auxiliary power supply is provided using a galvanically-separated power pack.
Since auxiliary voltage needs to be isolated from the ground, “galvanically separated converters” in accordance with IEC
standard 60950 (UL 1950) or equivalent IEC 60364-41 and CEI 64-8, have to be used to guarantee a current in common mode
or leakage current (as defined in IEC 478/1 and CEI 22/3) no greater than 3.5 mA.
Presence of the auxiliary power supply enables the relay unit to be used even with the circuit breaker open, as well as powering all the modules.
The characteristics of the power pack are given in the table below.
Characteristics LSIG-MM Version
Auxiliary voltage
(galvanically separated) 24V DC ±20%
Maximum ripple 5%
Inrush current @ 24 V ~2 A for 5 ms
Rated power @ 24 V ~3 W
3.1.3 Environmental characteristics
Operating temperature
-25 °C ... +70 °C
Storage temperature -40 °C ... +90 °C
Relative humidity 0% ... 98% with condensation
Degree of protection (with LSIG-MM installed in the CB) IP 30
3.1.4 Description of input/output
3.1.4.1 Binary input
- K14/K15: this input allows activating MM protection.
The input is connected on K14 and K15 connectors.
The signal is 0 (MM not active) ... 24 V (MM active)
It is important to fulfill the right polarity:
K14 (+)
K15 (-)
3.1.4.2 Binary output
- 95S/98S: this output gives a feedback on MM protection status.
If MM protection is active, the contact is closed, otherwise is open.
3.1.5 Communication bus
External system bus, RS 485 physical interface, Modbus RTU protocol, baud rate 9600-19200 bps.
3.1.6 Protection functions
The LSIG-MM units carry out the following independent protection functions:
1. Protection against overload with inverse time “L”;
2. Protection against short-circuit with adjustable delay “S”;
3. Protection against instantaneous short-circuit “I”;
4. Protection against earth fault with adjustable delay “G”;
5. Protection against instantaneous short circuit at high currents “I inst”;
6. Protection against phase unbalance “U”;
7. Protection against overtemperature “OT”;
8. Protection for maintenance mode “MM”;
The LSIG-MM units allow processing of current signal of neutral pole with different relationships relative to the value of the phases.
N.B.: Beyond 15.5xIn of current on the Ne, the protection is considered as being set to 100%.
A timing indication (message + “alarm” LED) is provided on unit’s display, which is activated during a protection alarm. It is disabled when the
alarm condition ceases or when the protection has been tripped. When the circuit breaker opens, the page with “Trip” data is displayed (when “i
Test” is pressed, or automatically when a Vaux is installed).
3.1.6.1 RMS calculation
All protection functions perform their respective processing on the basis of the real rms value of currents and voltages (protection G is disabled
for current values greater than 8In (where I
4
≥ 0.8In), greater than 6In (where 0.5In≤ I
4
<0.8In) and greater than 4In (where I4<0.5In).
If the waveform is distorted beyond the established limit (6.3@2 In), the tolerance for the calculation of the true rms value will increase.
3.1.6.2 Harmonic distortion
The LSIG-MM units signal that a peak factor of 2.1 has been exceeded through a warning message and “warning” LED lighting up (remember
that IEC 60947-2 standard annex “F” provides that the protection unit must operate correctly with a peak factor ≤ 2.1, up to 2xIn).