Smart earth leakage protection - Circutor

Industrial earth leakage protectionDefinitionWhen the earth leakage protection systemdetects a fault current, it acts on theelectrical installation being protected,opening the circuit while interruptingthe supply of electrical energy, thus preventingthe danger of electrocution forpersons when the fault current reachesdangerous values, either as a result ofdirect or indirect contact, including anypotential damage caused to goods andmaterials.An earth leakage protection system iscomposed of three clearly different parts:}}Detecting element or sensor}}Relay}}Circuit breakerceived by the sensor and either sendsthe trigger signal to the associated circuitbreaker or not, depending on thesensitivity and delay time values programmed.Circuit breaker: This element acts asthe current interrupting element. It canbe a circuit breaker (with trigger coil), acontact, etc.These three elements can be found inCIRCUTOR's products with differentconfigurations:}}All elements separately}}Relay with internal transformerDetecting element or sensor: Currenttransformer that detects the earthleakage current of active conductors inan installation, sending a proportionalsignal to the relay. It can have a toroidalor rectangular geometry, depending onthe arrangement of plates or the wiringof the installation location.The correct operation of the sensor requiresthe path of capacitors to be asperfectly aligned as possible.Relay: Smart protection element. Itmeasures and treats the signal re-Immunised earth leakage protectionNowadays, "sympathy" or unwantedtriggers are quite common in modern installations.In these cases, one or moreearth leakage switches are triggered simultaneously,protecting an installationfrom the leakage currents sent to earthas a result of capacitive effects causedby the installation.Said capacitive effects can explained bytwo reasons:}}The installation's cables cause earthingcondensation effects. The longer thecable, the greater the capacity effect}}The capacitors of EMI filters in theequipment with electronic power regulationThe different loads or consumption of aninstallation can be classified in two maingroups, depending on the type of insulationfrom earth:Loads with no earthed capacitorsThe insulation existing between the unitand the earthing elements can be representedwith a pure Ohmic resistance.If the resistance is not high enough, nocurrent will pass through the earthingelements. The leakage current is zero(current passing to earth under normalconditions).In case there is an insulation fault, currentwill pass through earthing elements,the so-called fault earthed current, I d.P1-4