JPH11206001A - Protector for motor - Google Patents

Protector for motor

Info

Publication number
JPH11206001A
JPH11206001A JP119498A JP119498A JPH11206001A JP H11206001 A JPH11206001 A JP H11206001A JP 119498 A JP119498 A JP 119498A JP 119498 A JP119498 A JP 119498A JP H11206001 A JPH11206001 A JP H11206001A
Authority
JP
Japan
Prior art keywords
relay
motor
induction motor
current
starting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP119498A
Other languages
Japanese (ja)
Inventor
Masahiko Sakuraba
雅彦 桜庭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
Original Assignee
Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Meidensha Corp, Meidensha Electric Manufacturing Co Ltd filed Critical Meidensha Corp
Priority to JP119498A priority Critical patent/JPH11206001A/en
Publication of JPH11206001A publication Critical patent/JPH11206001A/en
Pending legal-status Critical Current

Links

Landscapes

  • Emergency Protection Circuit Devices (AREA)
  • Protection Of Generators And Motors (AREA)

Abstract

PROBLEM TO BE SOLVED: To accurately and swiftly detect delays in starting of a motor. SOLUTION: An induction motor IM is provided with a three-phase power supply via an electromagnetic contactor VCS. A sequence control circuit is provided with a power supply via a transformer PT for obtaining a control supply voltage. A phase U and a phase W of the three-phase power supply UVW provided to the induction motor 1M are provided a with a current transformer CT, respectively. The secondary-side outputs of the current transformers CT are supplied to a 2E-relay 2ERY which detects overloading and disconnection in the induction motor IM. The 2E-relay 2ERY is provided with a start delay detection relay SRY on its output side. The start delay detection relay SRY monitors current every second, for example, and compares the present current value with the previous value. If the current value has not decreased, that is, the current value is constant regardless of the lapse of time, the start delay detection relay SRY sends out a contact signal. The contact SRYb of the sequence circuit is turned off by the contact signal, to stop the starting of the induction motor IM.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】この発明は、電動機の始動時
における電動機の保護装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor protection device at the time of starting the motor.

【0002】[0002]

【従来の技術】通常、電動機を過電流等から保護するた
めには、サーマルリレーやタイマー等を使用している。
サーマルリレーは、電動機の許容過電流−時間特性以内
に電流が減衰しない場合に、図2に示すように、電動機
の始動渋滞(電動機の始動時、始動が停止して始動電流
が一定になってしまうこと)と見なす方法で、始動渋滞
そのものの検出ではない。また、サーマルリレーは、精
度が悪いため、電動機が、正規の始動時間以上の時間、
拘束されても支障が生じないように設計されている。
2. Description of the Related Art Normally, a thermal relay, a timer, and the like are used to protect an electric motor from an overcurrent or the like.
When the current does not decay within the allowable overcurrent-time characteristic of the motor, as shown in FIG. 2, the thermal relay starts congesting the motor (when the motor is started, the starting stops and the starting current becomes constant). This is not the detection of the start congestion itself. In addition, thermal relays have poor accuracy, so the motor will run for longer than the normal starting time,
It is designed so that there is no problem even if it is restrained.

【0003】電動機の始動中の発熱量は、始動時間だけ
拘束された場合の発熱量の1/2〜1/3程度である。このた
め、通常、電動機は、始動時間に相当する時間、拘束さ
れても支障が生じないように構成されている。
The amount of heat generated during start-up of the electric motor is about 1/2 to 1/3 of the amount of heat generated when the motor is restricted for the start-up time. For this reason, usually, the electric motor is configured such that no trouble occurs even if the electric motor is restrained for a time corresponding to the starting time.

【0004】また、タイマーによる電動機の保護の場
合、始動渋滞がどうかの判定は、最低電圧での始動時間
以内に始動が完了したかどうかによって判定している。
[0004] In the case of protecting the motor by a timer, it is determined whether or not there is congestion in the starting operation based on whether or not the starting is completed within the starting time at the minimum voltage.

【0005】[0005]

【発明が解決しようとする課題】上記のように、サーマ
ルリレーによる電動機の保護は、始動時間に相当する時
間、拘束されても支障が生じないように構成されている
ため、始動渋滞が発生して直ちに電源から切り離されて
保護させる場合に比べて2〜3倍の熱容量を持つように
しなければならない。
As described above, the protection of the electric motor by the thermal relay is configured so as not to cause any trouble even if the electric motor is restrained for a time corresponding to the starting time. It must have a heat capacity two to three times that of the case where the power supply is immediately disconnected from the power supply and protected.

【0006】また、タイマーによる電動機の保護の場合
には、電動機は最大電圧でも最低電圧での始動時間以上
の許容拘束時間をもった熱特性とする必要があるため、
ブロアなどの重慣性負荷では構成が極めて困難になる。
Further, in the case of protecting the motor by a timer, the motor must have a thermal characteristic having an allowable restraining time longer than the starting time at the minimum voltage even at the maximum voltage.
A heavy inertial load such as a blower makes the configuration extremely difficult.

【0007】さらに、電動機の許容拘束時間は、電源電
圧の変動によって変化するが、上記リレーでは、電源電
圧の変動による自動補正ができない。従って、電動機
は、上記リレーが確実に動作するまでの時間、始動渋滞
に十分耐える必要がある。
Further, the allowable restraint time of the motor changes due to the fluctuation of the power supply voltage. However, the above-mentioned relay cannot automatically correct the fluctuation due to the fluctuation of the power supply voltage. Therefore, it is necessary that the electric motor sufficiently withstand the start traffic until the relay operates reliably.

【0008】この発明は上記の事情に鑑みてなされたも
ので、電動機の始動渋滞を正確かつ迅速に検出できるよ
うにした電動機の保護装置を提供することを課題とす
る。
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a motor protection device capable of accurately and quickly detecting a start-up congestion of a motor.

【0009】[0009]

【課題を解決するための手段】この発明は、上記の課題
を達成するために、電磁接触器と、この電磁接触器を介
して三相電源が供給される誘導電動機と、この誘導電動
機の過負荷や断線を検出する第1リレーと、この第1リ
レーの入力側あるいは出力側に設けられ、誘導電動機の
始動電流が前回値と比較して減少していないときに動作
する第2リレーとを備え、第2リレーが動作したとき、
前記電磁接触器を開放させるようにしたことを特徴とす
るものである。
SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an electromagnetic contactor, an induction motor to which three-phase power is supplied via the electromagnetic contactor, and an overdrive of the induction motor. A first relay for detecting a load or disconnection, and a second relay provided on the input side or the output side of the first relay and operating when the starting current of the induction motor has not decreased from the previous value. When the second relay is activated,
The electromagnetic contactor is opened.

【0010】[0010]

【発明の実施の形態】以下この発明の実施の形態を図面
に基づいて説明する。図1はこの発明の実施の形態を述
べる回路構成図で、図1において、IMは誘導電動機、VC
Sは電磁接触器、PTは制御電源電圧を得るための変圧器
である。誘導電動機IMに供給する三相電源UVWのU相と
W相にはそれぞれ変流器CTが設けられる。
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram illustrating an embodiment of the present invention. In FIG. 1, IM denotes an induction motor, VC
S is an electromagnetic contactor, and PT is a transformer for obtaining the control power supply voltage. Current transformers CT are provided for the U-phase and the W-phase of the three-phase power supply UVW supplied to the induction motor IM, respectively.

【0011】変流器CTの2次側の出力は、誘導電動機IM
の過負荷や断線を検出する2Eリレー2ERYに供給され
る。2Eリレー2ERYの出力側には始動渋滞検出リレー
SRYを設ける。この始動渋滞検出リレーSRYは、例えば、
1秒毎に電流を監視し、前回値と比較して減少していな
い場合、すなわち図2に示すように時間の経過にかかわ
らず電流が一定値になる場合、には接点信号を送出す
る。この接点信号で後述のシーケンス回路の接点SRYbを
オフさせる。なお、Aは電流計である。
The output of the secondary side of the current transformer CT is an induction motor IM.
Is supplied to a 2E relay 2ERY for detecting an overload or a disconnection of the relay. 2E relay 2ERY output start congestion detection relay
SRY is provided. This start traffic jam detection relay SRY is, for example,
The current is monitored every second and a contact signal is sent if the current has not decreased from the previous value, that is, if the current has a constant value regardless of the lapse of time as shown in FIG. The contact signal turns off a contact SRYb of a sequence circuit described later. A is an ammeter.

【0012】図2に示すように、電動機の始動電流は、
回転速度の上昇とともに、減少するが、途中で始動渋滞
を生じた場合、電流はその時点で変化(減少)しなくな
る。従って、前記始動渋滞検出リレーSRYによって、始
動完了前に電流が減少しなくなったかどうかを検出する
と、誘導電動機IMの始動渋滞の発生が、即時に検出でき
るようになる。
As shown in FIG. 2, the starting current of the motor is
The current decreases as the rotation speed increases. However, if a start congestion occurs on the way, the current does not change (decrease) at that time. Accordingly, when the start congestion detection relay SRY detects whether or not the current has stopped decreasing before the start is completed, the occurrence of the start congestion of the induction motor IM can be immediately detected.

【0013】前記シーケンス回路は、誘導電動機IMの運
転を行う制御回路で、運転スイッチSWを押すと、電磁接
触器VCSの励磁コイルVCSXが付勢されて電磁接触器VCSが
投入され、接点VCSXaにより励磁コイルVCSXは自己保持
される。運転を開始した誘導電動機IMの始動電流は、図
2に示すような特性で時間の経過とともに、減少して行
く。しかし、始動途中で渋滞したときには、電流の減少
がなくなり、一定となる。
The sequence circuit is a control circuit for operating the induction motor IM. When the operation switch SW is pressed, the exciting coil VCSX of the electromagnetic contactor VCS is energized, and the electromagnetic contactor VCS is turned on. The excitation coil VCSX is held by itself. The starting current of the induction motor IM that has started operation decreases with time with the characteristics shown in FIG. However, when there is traffic congestion during the start, the current does not decrease and becomes constant.

【0014】すると、この一定電流を始動渋滞検出リレ
ーSRYが検出し、その接点SRYbをオフさせるため、シー
ケンス回路中の励磁コイルVCSXは消勢され、電磁接触器
VCSを開放する。これにより、誘導電動機IMの始動は停
止される。
Then, the starting congestion detection relay SRY detects this constant current and turns off its contact SRYb, so that the excitation coil VCSX in the sequence circuit is deenergized and the electromagnetic contactor
Release VCS. Thereby, the starting of the induction motor IM is stopped.

【0015】なお、シーケンス回路中の停止スイッチSW
は、運転停止用のものであり、2ERYbは、2Eリレー
が過負荷等を検出したときに、一定時限後にオフする接
点である。
The stop switch SW in the sequence circuit
Is a contact for stopping the operation, and 2ERYb is a contact that turns off after a certain time limit when the 2E relay detects an overload or the like.

【0016】[0016]

【発明の効果】以上述べたように、この発明によれば、
電動機の始動渋滞が即時に検出できるため、小さな許容
拘束時間特性の電動機の採用が可能となるとともに、電
動機の許容拘束時間を大きくするため、電動機の形状を
大型化したり、回転子バーの形状を特殊に形成したりす
ることが不要となる利点がある。また、始動渋滞検出リ
レーは電流の増減だけの比較のため、絶対値は問題にな
らなくなり、電流値と時限特性をその都度設定する必要
が省ける利点があるとともに、変圧器などの電源側の過
負荷耐量が小さくて済むようなる。さらに、負荷側の要
因による始動渋滞の場合でも、即時に検出できるため、
負荷設備でのトラブルが軽微なうちに対策着手が可能と
なる。
As described above, according to the present invention,
Since the starting congestion of the motor can be immediately detected, it is possible to employ a motor having a small allowable restraint time characteristic. There is an advantage that special formation is not required. Since the starting congestion detection relay compares only the increase and decrease of the current, the absolute value does not matter, so there is an advantage that it is not necessary to set the current value and the time characteristic each time. The load tolerance can be reduced. Furthermore, even in the case of starting congestion due to factors on the load side, it can be detected immediately,
It is possible to start measures while the trouble in the load equipment is minor.

【図面の簡単な説明】[Brief description of the drawings]

【図1】この発明の実施の形態を述べる回路構成図。FIG. 1 is a circuit configuration diagram illustrating an embodiment of the present invention.

【図2】電動機の始動電流と始動渋滞したときの時間−
電流特性図。
FIG. 2 shows the starting current of the electric motor and the time when the starting congestion occurs.
FIG.

【符号の説明】[Explanation of symbols]

SRY…始動渋滞検出リレー VCS…電磁接触器 IM…誘導電動機 2ERY…リレー CT…変流器 SRY… Start congestion detection relay VCS… Electromagnetic contactor IM… Induction motor 2ERY… Relay CT… Current transformer

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 電磁接触器と、この電磁接触器を介して
三相電源が供給される誘導電動機と、この誘導電動機の
過負荷や断線を検出する第1リレーと、この第1リレー
の入力側あるいは出力側に設けられ、誘導電動機の始動
電流が前回値と比較して減少していないときに動作する
第2リレーとを備え、第2リレーが動作したとき、前記
電磁接触器を開放させるようにしたことを特徴とする電
動機の保護装置。
1. An electromagnetic contactor, an induction motor to which three-phase power is supplied via the electromagnetic contactor, a first relay for detecting an overload or disconnection of the induction motor, and an input of the first relay And a second relay that is provided on the output side or the output side, and that operates when the starting current of the induction motor has not decreased from the previous value. When the second relay operates, the electromagnetic contactor is opened. A protective device for an electric motor, characterized in that:
JP119498A 1998-01-07 1998-01-07 Protector for motor Pending JPH11206001A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP119498A JPH11206001A (en) 1998-01-07 1998-01-07 Protector for motor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP119498A JPH11206001A (en) 1998-01-07 1998-01-07 Protector for motor

Publications (1)

Publication Number Publication Date
JPH11206001A true JPH11206001A (en) 1999-07-30

Family

ID=11494659

Family Applications (1)

Application Number Title Priority Date Filing Date
JP119498A Pending JPH11206001A (en) 1998-01-07 1998-01-07 Protector for motor

Country Status (1)

Country Link
JP (1) JPH11206001A (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103311889A (en) * 2013-06-29 2013-09-18 襄垣县树元电器有限公司 Manual switching protection circuit for dual power supplies
WO2019124396A1 (en) * 2017-12-18 2019-06-27 ダイキン工業株式会社 Air conditioner
US11365335B2 (en) 2017-12-18 2022-06-21 Daikin Industries, Ltd. Composition comprising refrigerant, use thereof, refrigerating machine having same, and method for operating said refrigerating machine
US11435118B2 (en) 2017-12-18 2022-09-06 Daikin Industries, Ltd. Heat source unit and refrigeration cycle apparatus
US11441802B2 (en) 2017-12-18 2022-09-13 Daikin Industries, Ltd. Air conditioning apparatus
US11441819B2 (en) 2017-12-18 2022-09-13 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11492527B2 (en) 2017-12-18 2022-11-08 Daikin Industries, Ltd. Composition containing refrigerant, use of said composition, refrigerator having said composition, and method for operating said refrigerator
US11493244B2 (en) 2017-12-18 2022-11-08 Daikin Industries, Ltd. Air-conditioning unit
US11506425B2 (en) 2017-12-18 2022-11-22 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11535781B2 (en) 2017-12-18 2022-12-27 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11549695B2 (en) 2017-12-18 2023-01-10 Daikin Industries, Ltd. Heat exchange unit
US11549041B2 (en) 2017-12-18 2023-01-10 Daikin Industries, Ltd. Composition containing refrigerant, use of said composition, refrigerator having said composition, and method for operating said refrigerator
US11820933B2 (en) 2017-12-18 2023-11-21 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11906207B2 (en) 2017-12-18 2024-02-20 Daikin Industries, Ltd. Refrigeration apparatus

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103311889A (en) * 2013-06-29 2013-09-18 襄垣县树元电器有限公司 Manual switching protection circuit for dual power supplies
WO2019124396A1 (en) * 2017-12-18 2019-06-27 ダイキン工業株式会社 Air conditioner
US11365335B2 (en) 2017-12-18 2022-06-21 Daikin Industries, Ltd. Composition comprising refrigerant, use thereof, refrigerating machine having same, and method for operating said refrigerating machine
US11435118B2 (en) 2017-12-18 2022-09-06 Daikin Industries, Ltd. Heat source unit and refrigeration cycle apparatus
US11441802B2 (en) 2017-12-18 2022-09-13 Daikin Industries, Ltd. Air conditioning apparatus
US11441819B2 (en) 2017-12-18 2022-09-13 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11492527B2 (en) 2017-12-18 2022-11-08 Daikin Industries, Ltd. Composition containing refrigerant, use of said composition, refrigerator having said composition, and method for operating said refrigerator
US11493244B2 (en) 2017-12-18 2022-11-08 Daikin Industries, Ltd. Air-conditioning unit
US11506425B2 (en) 2017-12-18 2022-11-22 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11535781B2 (en) 2017-12-18 2022-12-27 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11549695B2 (en) 2017-12-18 2023-01-10 Daikin Industries, Ltd. Heat exchange unit
US11549041B2 (en) 2017-12-18 2023-01-10 Daikin Industries, Ltd. Composition containing refrigerant, use of said composition, refrigerator having said composition, and method for operating said refrigerator
US11820933B2 (en) 2017-12-18 2023-11-21 Daikin Industries, Ltd. Refrigeration cycle apparatus
US11906207B2 (en) 2017-12-18 2024-02-20 Daikin Industries, Ltd. Refrigeration apparatus

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