JPS58143432U

JPS58143432U - motor protection relay

Info

Publication number: JPS58143432U
Application number: JP3931682U
Authority: JP
Inventors: 正己榊原; 岡戸　弘行; 博飯田; 長尾　良章; 近藤　一三; 和田　勇一
Original assignee: 三菱電機株式会社
Priority date: 1982-03-19
Filing date: 1982-03-19
Publication date: 1983-09-27

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

第１図は従来のモータ保護リレーの構成を示すブロック
図、第２図は本考案に係るモータ保護リレーの構成を示
すブロック図である。各図中同一部材には同一符号を付し、１０は変流器、１
２は過電流検出回路、１４は不平衡率判定回路、１４ａ
は起動待不平衡率判定回路、ｉ４ｂは運転時不平衡率判
定回路、１６は反相検出回路、２０はリレー回路、３２
は起動検出回路、２４は起動時間設定器、２２．３４は
アンド回路、３０は電源電圧検出回路、１８．２８はオ
ア回路、２６はノット回路である。FIG. 1 is a block diagram showing the structure of a conventional motor protection relay, and FIG. 2 is a block diagram showing the structure of a motor protection relay according to the present invention. Identical members in each figure are given the same reference numerals; 10 is a current transformer; 1 is a current transformer;
2 is an overcurrent detection circuit; 14 is an unbalance rate determination circuit; 14a
is a start-up unbalance rate determination circuit, i4b is an operation unbalance rate determination circuit, 16 is an antiphase detection circuit, 20 is a relay circuit, 32
24 is a startup detection circuit, 24 is a startup time setter, 22.34 is an AND circuit, 30 is a power supply voltage detection circuit, 18.28 is an OR circuit, and 26 is a NOT circuit.

Claims

[Scope of utility model registration request]

(1) A current transformer that detects the load current of the three-phase motor main circuit, an overcurrent detection circuit that outputs an overcurrent signal when the load current exceeds a set reference value, and an unbalance rate of the load current. an unbalance rate determination circuit that calculates the unbalance rate and outputs an unbalance signal when the unbalance rate exceeds a set reference value; and an unbalance rate determination circuit that determines whether the motor is connected in positive phase or in reverse phase and when the motor is connected in reverse phase. an anti-phase detection circuit that outputs an anti-phase signal to the overcurrent signal, an unbalanced signal, and an anti-phase signal;
a relay circuit that opens the main circuit when one signal is output; The anti-phase detection circuit consists of a circuit that sets the set reference value low after the elapse of time, and the anti-phase detection circuit consists of a circuit that analyzes the power supply voltage of the motor main circuit to detect anti-phase connection of the motor. A motor protection relay characterized in that it is provided with an anti-phase signal stop device that prevents output of an anti-phase signal to a relay circuit after a predetermined period of time has elapsed after activation.

(2) Utility Model Registration Scope of Claim (1) In the motor protection relay described in claim (1), the unbalance rate determination circuit includes a start-up unbalance rate determination circuit with a high set standard value and an operation time with a low set standard value. When starting the motor, the -unbalance rate of the load current is determined by the starting unbalance rate determining circuit, and after a predetermined time has elapsed after startup, the running unbalance rate determining circuit determines the -unbalance rate of the load current. A motor protection relay characterized by:

(3) In the motor protection relay described in utility model registration claim (1) or (2), the anti-phase signal stop device includes a start detection circuit that detects the start of the motor and outputs a start detection signal for a predetermined period of time after the motor starts. and an AND circuit that outputs an anti-phase signal only when the start detection signal and the anti-phase signal are both output.