JPS58143431U

JPS58143431U - motor protection relay

Info

Publication number: JPS58143431U
Application number: JP3829182U
Authority: JP
Inventors: 正己榊原
Original assignee: 三菱電機株式会社
Priority date: 1982-03-18
Filing date: 1982-03-18
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
すプロ□ツク図である。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
は起動時不平衡率判定回路、１４ｂ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、３０
は起動検出回路、２４は起動時間設定器、２２．３２は
アンド回路、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 the 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
14b is a startup unbalance rate determination circuit, 14b is an operation unbalance rate determination circuit, 16 is an antiphase detection circuit, 20 is a relay circuit, and 30
24 is a startup detection circuit, 24 is a startup time setter, 22.32 is an AND 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 a relay circuit that opens the main circuit when at least one of the overcurrent signal, unbalanced signal, and antiphase signal is output. In the motor protection relay including, the unbalance rate determination circuit is a circuit that sets a high setting standard value of the unbalance rate at the time of starting the motor, and sets the setting standard value low after a predetermined time has elapsed after the motor starting, The anti-phase detection circuit is configured to detect anti-phase connection of the motor by analyzing the load current of the motor main circuit. A motor protection relay characterized by being provided with a reverse phase signal stop device that blocks output.

(2) Utility model registration 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 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 passed after startup, the unbalance rate determining circuit determines the unbalance rate of the load current. A motor protection relay that is characterized by making respective determinations.

(3) Scope of claims for utility model registration (1) or (2)
In the motor protection relay described above, 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 time after the motor starts, and when both the start detection signal and the anti-phase signal are output. A motor protection relay comprising: an AND circuit that outputs an antiphase signal.