Rockwell Automation 140G-NTK-E12 LSIG and LSIG-MM Release - Manual (Page 6)

DIR 1000587R0002 (L3821)
(6)
2.1.3 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 installed in the CB) IP 30
2.1.4 Protection functions
The LSIG protection unit carries out 5 independent protection functions, i.e.:
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 “Iinst”.
The LSIG unit allows 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 (“alarm” LED) is provided on front side of unit, which is enabled during an alarm for each protection. It is disabled when the
alarm condition ceases or when the protection has been tripped.
The unit has a “backup-protection” function. If the circuit breaker does not open immediately the first time the Trip Coil is hit (partial TC failure),
TRIP commands are sent repeatedly until the circuit breaker opens.
For inverse-time protections, the relationship between trip time and overcurrent is given by the formula: t = k/I 2 .
For fixed-time protections with an adjustable delay, the relationship adopted is as follows: t = k.
2.1.4.1 RMS calculation
All protection functions perform their respective processing cycles on the basis of real rms value of currents (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 I
4
<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.
2.1.4.2 Watchdog
The LSIG unit provides some watchdog functions which can guarantee proper management of relay malfunctions. These functions are as follows:

Rating Plug validity
 Watchdog for proper connection of current sensors (CS). Any faults are indicated by a glowing LED, as explained in par. 2.7.1.
 Watchdog for proper opening solenoid connection (TC). Any faults are indicated by a glowing LED, as explained in par. 2.7.1.
2.1.5 Description of protection functions
2.1.5.1 Protection “L”
"L” is the only protection that cannot be disabled because it is for self-protection against overloading of the relay.
The type of curve that can be set is t=k/I 2 .
Protection trip time - inverse time - is given by the expression:
max
9 t
1
(I / I )
f 1
2
, 1
where l
f
≤ 12In, 1s where l
f
> 12In
I
f
is the fault current and I
1
the protection threshold set by user.
NB: Time expressed in seconds.
2.1.5.2 Protection “S”
This protection can be disabled; it can be of the fixed time (t=k) or inverse time (t=k/I 2 ) type. In the latter case, trip time is given by the expression
max
100 t
2
(I )
f
2
, t
2
/ I
n
where l
f
> l
2
I
f
is the fault current and I
2
the protection threshold set by user.
NB: Time expressed in seconds.
2.1.5.3 Protection “I”
This fixed time (t=k) protection can be disabled and is designed for a nil intentional delay.
2.1.5.4 Protection “G”
This protection can be disabled; it can be of the fixed time (t=k) or inverse time (t=k/i 2 ) type. In the latter case, trip time is given by the expression
where l = l
f
/ l
4
I
f
is the fault current and I
4
the protection threshold set by user.
NB: Time expressed in seconds.