RO98911B1

RO98911B1 - Device for protection against biphase operation and overload

Info

Publication number: RO98911B1
Application number: RO129462A
Authority: RO
Inventors: Marius-Mihael Costan
Original assignee: îNTREPRINDEREA "ELECTROCONTACT"
Priority date: 1987-08-17
Filing date: 1987-08-17
Publication date: 1990-04-30

Abstract

Inventia se refera la un dispozitiv de protectie antibifazica si la suprasarcina, care realizeaza protectia pe toate trei fazele de alimentare ale unui motor, prin controlul curentului unei singure faze, având posibilitatea de a sesiza atât depasirea unei valori prestabilite cât si anularea sau scaderea la o valoare foarte mica a curentului controlat. Dispozitivul este alcatuit dintr-un circuit de intrare-prescriere înseriat cu faza controlata, tensiunea furnizata de acesta fiind prelucrata cu ajutorul unui circuit de obtinere a modulului tensiunii si a unui compaator, impulsurile de tensiune obtinute dupa comparator fiind introduse într-un analizor al duratei impulsurilor conectat la un circuit monostabil retriggerabil, care comanda una din intrarile unui circuit logic SI, cealalta intrare a circuitului logic SI fiind conectata la un circuit de temporizare declansat de tensiunea de alimentare, iar iesirea circuitului logic SI comandând un element de executie care controleaza alimentarea bobinei contactorului, blocul de alimentare a dispozitivului si bobina contactorului primind tensiune de la faza retelei corespunzatoare fazei controlate a motorului.The invention relates to an antibiotic and overload protection device that protects all three power phases of an engine by controlling the current of a single phase, having the possibility to sense both the overrun of a preset value and the cancellation or decrease to a very low value of controlled current. The device consists of an input-prescribing circuit connected to the controlled phase, the voltage supplied by it being processed by means of a circuit for obtaining the voltage module and a compactor, the voltage pulses obtained after the comparator being introduced into a time analyzer of the pulses connected to a retrigable monostable circuit which controls one of the inputs of an SI logic circuit, the other input of the SI logic circuit being connected to a timing circuit triggered by the supply voltage, and the output of the logic circuit SI by commanding a controlling element controlling the supply the contactor coil, the device supply block and the contactor coil receive voltage from the phase of the network corresponding to the controlled phase of the motor.