CN201994635U

CN201994635U - Auto-transformer protective device

Info

Publication number: CN201994635U
Application number: CN2011201339876U
Authority: CN
Inventors: 李建民; 赵姜坤
Original assignee: QUJING QIANKUN PAPER CO Ltd
Current assignee: QUJING QIANKUN PAPER CO Ltd
Priority date: 2011-04-29
Filing date: 2011-04-29
Publication date: 2011-09-28
Anticipated expiration: 2021-04-29

Abstract

Provided is an auto-transformer protective device. By the adoption of the auto-transformer protective device on existing auto-coupling voltage reduction starting control circuits, auxiliary contacts of existing electric appliance components are utilized, a pair of normally closed auxiliary contacts of a master contactor is connected in series to a path of winding of an intermediate relay, another pair of normally open auxiliary contacts is connected to a path of winding of the master contactor, and time delay break contacts of a time relay is connected in series to a path of winding of a conversion contactor. The auto-transformer protective device has the advantages of protecting an auto-transformer from being burnt out and prolonging service life of the intermediate relay.

Description

The autotransformer protective device

Technical field

The utility model relates to the fault secure circuit of AC asynchronous motor self coupling reduced voltage starter, can guarantee the not impaired device of self coupling reduced voltage starter and motor when especially element breaks down in self coupling reduced voltage starter running or before starting.

Background technology

At present, on the market self coupling reduced-voltage starting control cabinet be a kind ofly be widely used, reduced-voltage starting complete sets of products that cost performance is higher, AC asynchronous motor generally adopts this device to carry out reduced-voltage starting.The situation that this device inner member breaks down in the use happens occasionally, and particularly auxiliary relay can cause autotransformer to burn out after damaging.The value of autotransformer accounts for 70% in the self coupling reduced-voltage starting control cabinet, will bring than the large economy loss to the user in case damage, and also might burn out motor when serious.

As among Fig. 1 when the starter motor M, press start button SB2, move the corresponding main and auxiliary contact that helps of conversion contactor KM1, KM2, the back self-sustaining of loosing one's grip is switched on, KM2 gets electric back time relay KT and gets electric and by the time delays closing contact KT that sets, after the KT closure auxiliary relay KA get electric, KA corresponding contacts closure, main contactor KM3 gets and electricly correspondingly main and auxiliaryly helps contact action and finish self coupling reduced-voltage starting process.If auxiliary relay KA fault occurring is failure to actuate and will causes main contactor KM3 can't get the electric KM2 of causing and KM1 in running order always time, generating heat thereby the excision that can't finish autotransformer TA causes autotransformer TA and motor series operation burns out in this process.

Summary of the invention

In order to overcome in the present self coupling reduced-voltage starting control cabinet; after auxiliary relay breaks down before startup and in the running and damages; cause the deficiency that autotransformer burns out in the self coupling reduced-voltage starting control cabinet; the utility model provides a kind of autotransformer protective device, and this device can be realized the protection of autotransformer when auxiliary relay breaks down and reduce breakdown loss.

The technical scheme that its technical problem of the utility model device solves is taked is: on self coupling reduced-voltage starting control circuit, utilize the auxiliary contact of existing electric elements, with the pair of series in the normally closed auxiliary contact of main contactor in the auxiliary relay path of winding, another is connected in the main contactor path of winding often driving auxiliary contact, and the time-delay break contact of the time relay of connecting on conversion contactor coil branch road.

The utility model is in series with an auxiliary relay normally opened contact on the main contactor path of winding, a pair of main contactor in parallel often drives auxiliary contact on this contact, the a pair of self-holding contact of often opening is arranged on the path of winding of auxiliary relay, the normally closed auxiliary contact of a pair of main contactor of series connection before this contact, on the path of winding of switching relay with connect between the self-holding contact time-delay break contact of a pair of time relay of often opening of switching relay.

The utility model beneficial effect is: after this protective device can break down at the auxiliary relay of self coupling reduced voltage starter; autotransformer can't excise and cause heating to burn out; and when not increasing equipment, prolong the useful life of element; simple in structure; easy to operate; invest for a short time, effect is remarkable.

The utility model technology is described further as embodiment below in conjunction with Fig. 2.

Description of drawings

Fig. 1 is the electric elements connection diagram of prior art;

Fig. 2 is an electric component syndeton schematic diagram of the present utility model.

Embodiment

As Fig. 2, series connection one auxiliary relay normally opened contact KA on the path of winding of KM3, a pair of KM3's in parallel often drives auxiliary contact on this contact, purpose is to guarantee after auxiliary relay KA dead electricity the back self-sustaining of can switching on of main contactor KM3 coil, has on the path of winding of auxiliary relay KA that a pair of KA's often open self-holding contact; The normally closed auxiliary contact KM3 of a pair of main contactor KM3 of series connection before this contact, purpose is to finish reduced-voltage starting relief auxiliary relay in motor M to deactivate, and avoids long-time energising to cause shorten useful life; On the path of winding of switching relay KM2 with connect in the middle of the self-holding contact KM2 time-delay break contact of a pair of time relay KT of often opening of KM2, purpose is after auxiliary relay KA breaks down, main contactor KM3 can't get electronic work and can not finish conversion between autotransformer TA decompression starting and the operate as normal, make the long-time big electric current operation of autotransformer TA and produce heating and burn out, and after middle relay K A breaks down, owing to the effect of the time relay time-delay break contact KT motor is normally started after pressing start button SB2, remind operating personnel to check, loss is dropped to bottom line so that in time fix a breakdown.

Claims

1. autotransformer protective device; it is characterized in that: on self coupling reduced-voltage starting control circuit; utilize the auxiliary contact of existing electric elements; with the pair of series in the normally closed auxiliary contact of main contactor in the auxiliary relay path of winding; another is connected in the main contactor path of winding often driving auxiliary contact, and the time-delay break contact of the time relay of connecting on conversion contactor coil branch road.

2. autotransformer protective device according to claim 1; it is characterized in that: on the main contactor path of winding, be in series with an auxiliary relay normally opened contact; a pair of main contactor in parallel often drives auxiliary contact on this contact; the a pair of self-holding contact of often opening is arranged on the path of winding of auxiliary relay; the normally closed auxiliary contact of a pair of main contactor of series connection before this contact, on the path of winding of switching relay with connect between the self-holding contact time-delay break contact of a pair of time relay of often opening of switching relay.