User Manual

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xed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ashes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ash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