CN2152343Y

CN2152343Y - Reactance starter for motor

Info

Publication number: CN2152343Y
Application number: CN 93228036
Authority: CN
Inventors: 范懋源; 刘福田
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-04-26
Filing date: 1993-04-26
Publication date: 1994-01-05
Anticipated expiration: 2003-04-26

Abstract

The utility model relates to a reactance starter for motor, comprising a reactor, and a start control circuit. The start control circuit comprises a start button, a stop button, an AC contactor, a time delay relay and an intermediate relay. The utility model is characterized in that the reactor is a three phase reactor which comprises three coils with columnar iron cores and without magnet yoke. Three iron core coils are respectively connected between a three phase major loop and a motor in series for reduced voltage starting. Because the utility model adopts the non yoke type reactor, so the start of the motor is stable. Because of no current switching transformation effect, so the service life of the motor and the starter can be longer. At the same time, the cost of the starter is also decreased, the structure is simple, and the maintenance is convenient.

Description

Reactance starter for motor

The utility model relates to a kind of motor starter.

The motor reduced voltage starter that generally uses mainly contains two kinds at present, a kind of is from the lotus root reduced voltage starter, another kind is a controllable silicon soft-start by lowering voltage device, the former utilizes from the lotus root step-down transformer to add 60% or 80% line voltage to starter in start-up course, the excision single-circuit transformer was added in full voltage on the starter after startup was finished, and made its normal operation.This starter needs a common three-phase contactor and one five contact contactor or three contactors to switch single-circuit transformer, and its cost is higher; Handoff procedure will make motor bear the impact of primary current once more; On-load switches easy scaling loss contact; Inaccurate or contactor adhesion causes the power supply short circuit fault because of time relay action.The latter utilizes the step-down of controllable silicon slicing to make motor keep less starting current in start-up course.Its shortcoming is, utilizes the slicing reduced voltage starting, voltage waveform distortion, and peak current surpasses several times of ammeter indicated values, and is all unfavorable to electrical network and motor; Complex circuit, troublesome maintenance, cost height.

The purpose of this utility model is to overcome above-mentioned the deficiencies in the prior art, provides a kind of start-up course steady, dependable performance, the motor no yoke type reactance starter that cost is low.

Technical solution of the present utility model is: a kind of motor reactance starter, it comprises: reactor, the start-up control circuit of being made up of startup, stop button, A.C. contactor, the time relay, auxiliary relay etc., its special character is that described reactor is the no yoke type reactor, it constitutes a three-phase reactor that does not have yoke by three coils with columnar iron core, and the cross section of columnar iron core can be circular or square or prismatic or rectangle or other shapes.Three iron-core coils are serially connected in respectively between three-phase major loop and the motor, and with the contact of three-phase ac contactor mutually and connect.Described reactor winding has tap, to satisfy the start request of different model motor.

Reactor is a no yoke type, and its magnetic circuit forms by air, so it is not subjected to the restriction of the designing requirement of iron core, can obtain higher magnetic flux density, thereby have very big magnetizing current, satisfies the start request of motor.Adopting the no yoke type reactor can realize the smooth start motor, is to utilize the motor initial stage of operation to be the characteristic of inductive load, promptly with the reactor homophase, therefore under the effect of reactor inductance with the starting current of restrictions motor.When motor speed increased gradually, promptly load was resistive gradually, and terminal voltage of motor rises, electric current descends, and the voltage on the reactor and then descends, and this impels terminal voltage of motor to rise again, so circulation progressively improves motor speed, until reaching nearly synchronizing speed.On the reactor voltage reduce to very low after, by contactor the reactor short circuit is fallen again, motor enters full voltage operation.

The utility model compared with prior art has following characteristics.

1. dependable performance is started steadily, does not have switch current to change, thereby the contacts of contactor no-spark, and motor does not need to bear rush of current once more yet, has prolonged the useful life of motor and starter.Can not cause power supply short circuit simultaneously because of the contactor time-delay discharges.

2. simple in structure, easy to maintenance, cost is low, with from lotus root reduced voltage starting machine than low by about 20% approximately.

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is circuit theory diagrams of the present utility model.

Be described in further detail below in conjunction with accompanying drawing:

As Fig. 1, casing of the present utility model is the frame safeguard structure, and its casing front panel is provided with ammeter, indicator light, starts, stops control button.Reactor, A.C. contactor, auxiliary relay etc. are arranged in the casing.

As Fig. 2, three normally opened contacts of three-phase automatic air-break switch, main A.C. contactor XLL are serially connected in respectively between three-phase major loop and the motor.No yoke reactor is to be that circular iron core and the coil on iron core constitutes by three cross sections, and core of reactor and coil turn should design according to the size of motor power (output).Coil and the normally opened contact XLL two ends that are attempted by the major loop A.C. contactor after the normally opened contact of A.C. contactor QC is connected in series respectively.

The start-up control circuit is same as the prior art, also is by indication LD, UD, HD, starting button QA, stop button TA, A.C. contactor QC, time relay sj ₁, SJ ₂, intermediate relay ZJ, main A.C. contactor XLC etc. connect and compose by diagram.

Also include overload protecting circuit, it is by current transformer LH ₁, LH and the formations such as thermal relay that link to each other with instrument transformer respectively.

During startup, the air automatic switch ZK that closes, the start-up control circuit gets electric, indicator light HD(red light) luminous indication, press start button QA then, A.C. contactor QC action, its normally opened contact X ₃₁, X ₃₂, X ₃₇Closure, normally-closed contact disconnects, and power supply is given motor after the reactor step-down, make it begin to rotate, this moment, indicator light HD went out the UD(amber light) and send indication, after after a while, time relay sj ₁Action, its contacting intermediate relay ZJ, the normally opened contact closure of auxiliary relay is connected main A.C. contactor XLC, be serially connected in the normally opened contact XLC closure in the major loop, with the reactor short circuit, motor obtains full voltage, finish start-up course, this moment, indicator light VD went out the luminous indication of LD green light.Again after after a while, time relay sj ₂Action makes to exchange contact QC release, cuts off the reactor loop.

Claims

1, a kind of motor reactance starter, it comprises: reactor, the start-up control circuit of being made up of startup and stop button, A.C. contactor, the time relay, auxiliary relay etc., it is characterized in that described reactor is the no yoke type reactor, it constitutes a three-phase reactor that does not have yoke by three coils of wire with columnar iron core, three coils of wire are serially connected in respectively between three-phase major loop and the motor, and with the contact of three-phase ac contactor mutually and connect.

2, motor reactance starter according to claim 1 is characterized in that the described reactor coil of wire has tap.