Rockwell Automation 140G-NTK-E12 LSIG and LSIG-MM Release - Manual (Page 16)

DIR 1000587R0002 (L3821)
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3.1.9.5.1 Start-up threshold “G”
The start-up function can be selected in the case where the curve with fixed time is selected.
This function can be enabled and disabled in the protection “G” page.
The function behaves in exactly the same way as protection “S” (see par. 3.1.9.2.2)
3.1.9.6 Protection against phase unbalance “U”
Fixed-time protection - which can be excluded - trips when, for a time greater than or the same as the time t6 set, an unbalance is determined
between two or more phases higher than the set threshold I6. Range: 2 ... 90%, with 1% steps.
Unbalance percentage is therefore calculated
%Unb
where I
max
is the maximum and I
min
is the minimum phase current.
It is possible to disable trip control of protection (“Enable Trip: Off”).
In this case, for the whole duration of the unbalance the CB will not be opened, but only the condition will be signaled by means
of the “warning” LED lit up and a warning message.
When phase current value exceeds 6xIn, function “U” excludes itself because, in this case, the other protections are cut in as
the fault is considered a phase fault.
The protection is not enabled for maximum phase current values lower than 0.3xIn.
3.1.9.7 Protection against overtemperature inside the relay, “OT”
A sensor inside the LSIG-MM unit monitors the temperature of the unit.
This enables signalling of any abnormal temperature conditions, which could cause temporary or continuous failure of the unit’s electronic
components.
This protection has two states of operation:
State of “WARNING TEMPERATURE” with –25 °C < temp. < -20 °C or 70 °C < temp. < 85 °C : the display is turned off and
the “WARNING” LED flashes at 0.5 Hz.
State of “ALARM TEMPERATURE” with temp. < –25 °C or temp. > 85 °C : the display is turned off, the “WARNING” and “ALARM”
LEDs flash 2 Hz and Trip is activated (if enabled, by means of the “OverTemper. Trip = On” parameter).
N.B.:
 In the event of Warning and Alarm, the display is momentarily turned off, to preserve its functionality.
 The monitored temperature cannot be viewed on the display.
Protection is always active, both with auxiliary power supply and in self-powering.
Disabling Trip control of protection means that the LSIG-MM unit can work, with the circuit-breaker closed, in a range of tem-
peratures where correct operation of the electronics is not guaranteed.
3.1.9.8 Load control function
Single loads can be enabled/disabled on the load side before the overload protection L operates and trips the circuit breaker on the supply side.
Current thresholds are lower than those available with protection L, so that the load control can be used to prevent tripping due to overloads. This
function is active when an auxiliary power supply is installed, or power comes from LSIG-MM.
The operating logic involves activation of three contacts when the preset thresholds LC1, LC2 and I
w
are exceeded.
Thresholds LC1 and LC2 are expressed as a percentage of I
1
(current threshold set for protection L) while the “warning current” I
w
is expressed
as an absolute value. The values to be set are given in the following table:
Warning current Iw 0.30 ÷ 10.00 step 0.05xIn
Threshold LC1 50% ÷ 100%, 1% step xI
1
Threshold LC2 50% ÷ 100%, 1% step xI
1