CN2144363Y

CN2144363Y - Motor protection contactor

Info

Publication number: CN2144363Y
Application number: CN 92244280
Authority: CN
Inventors: 张开雄; 双浩云
Original assignee: Individual
Current assignee: Shuang Haorong
Priority date: 1992-12-10
Filing date: 1992-12-10
Publication date: 1993-10-20
Anticipated expiration: 2002-12-10

Abstract

The utility model relates to a motor protection contactor used for exception to occur in electric operating conditions. A protective circuit is arranged in a casing (3). In circuits, phase failure voltage signals detected by a voltage stabilizing diode DW and overload and short circuit current signals detected by two parallel current mutual inductors LH with the same polarity are respectively output onto a control pole in an or gate protection outlet circuit via a triode T[2] in a phase failure protective circuit, a triode T[3] and a thyristor KG[1] in an overload and short circuit protective circuit. The positive pole of a KG[2] is connected with the positive pole of a three-phase bridge rectifier Z[1], and the negative pole of the KG[2] is connected with a motor operation control loop. The motor protection contactor has the advantages of reliable performance, convenient use, little power consumption and assurance of no burning of the motor.

Description

Motor protection contactor

The utility model is that unusual protective device, particularly a kind of motor protection contactor appear in a kind of relevant electric operating mode.

In order to prevent motor when moving, lack the phenomenon generation that a live wire or overload are burnt motor for a certain reason, generally adopt electroheating type, voltage-type and current mode protector to solve.Because preceding type is that thermal relay can not guarantee electric motor normal working well, substituted by back two kinds just gradually now.The voltage-type protector, its phase failure signal takes out from the common point of the divider resistance of three-phase firewire series connection, and this is suitable for using on the motor of star connection, owing to the effect of motor windings induced potential, can not in time cut off the electricity supply after the phase failure; Also having a kind of connection, then is that three sampling resistance are connected into star, from taking-up phase failure signal between neutral point and the ground, and this connection, under the unbalanced situation of threephase load, the not phase failure also is easy to tripping operation, and influence is produced.The operation principle of current mode protector is the punching instrument transformer to be installed in detect phase failure signal on the three-phase firewire, drives relay work through amplifier and cuts off the electricity supply.This protector easily burns amplifier tube when induced current is big, and the cost height, and trouble is installed.Secondly, no matter voltage-type or current mode, structure is complicated, components and parts are many and all need to match with A.C. contactor, makes troubles to installation.Moreover protector is made independent complete machine, protect under the consciousness situation about differing people, it just become available can no product, therefore, do not reach the economic and social benefit of expection.

The purpose of this utility model is at above-mentioned defective, and a kind of motor protection contactor is provided, and no matter is when the phase failure or overload, short circuit, no matter the also motor of which kind of connection or three-phase imbalance, it all has very reliable protection effect to motor.

The purpose of this utility model is achieved in that in its shell and is provided with the phase failure; overload; short-circuit protection circuit; adopt voltage stabilizing didoe DW to take out phase failure voltage signal from the three-phase bridge rectifier Z2 that three-phase self coupling step-down transformer B links to each other; adopt two current transformer LH of same polarity parallel connection to detect overload; the short circuit current signal; this two signal is the triode T2 in open-phase protection circuit respectively; overload; T3 in the short-circuit protection circuit; controllable silicon KG1; transport to or door protection outlet circuit in KG2 control utmost point G on; the G utmost point is through R17 ground connection; the KG2 positive pole connects three-phase bridge rectifier Z1 positive pole; the KG2 negative pole links to each other with the motor rotation control loop; stop botton TN just is being connected in parallel on KG2; on the negative pole, the T2 emitter; the T3 collector electrode is connected on the three terminal integrated voltage stabilizer SW output that starts slowly in the power circuit.

In the aforementioned schemes, A.C. contactor shell and arc-extinguish chamber are fastened on the above-mentioned shell that the phase failure, overload, short-circuit protection circuit are housed by bolt.In the A.C. contactor shell, the mechanical locking device that A.C. contactor is housed and moves by the control contact that mechanical arm, release are formed.The trip coil two ends are serially connected in the no-voltage trip circuit that links to each other with the KG2 negative pole.The effect of no-voltage trip circuit is that the assurance motor is cut off the electricity supply when decompression (phase failure), stops motor rotation.In the no-voltage trip circuit, trip coil one termination KG3, KG2 negative pole, another termination C6 and Z1 negative pole, another termination of C6 D20 negative pole, KG3 positive pole and R16, the R16 other end and KG3 control utmost point ground connection.The D20 positive pole connects the Z1 positive pole.This is a kind of user friendly motor protecting device that A.C. contactor, the phase failure and overload, short-circuit protection are combined together.

And aforesaidly a kind ofly do not have and the motor protecting device that combines together of A.C. contactor; in its motor rotation control loop, can seal in a relay normally-closed contact, so that a fault-signal process or a door protection outlet circuit remove to trigger this relay; cut off the motor power supply circuits, the protection motor does not burn.

Take place for fear of the phenomenon that jeopardizes personal safety because of electric leakage, can such scheme or door protection outlet circuit in, be connected on its D17 positive pole by D18 and capacitor C 4 in parallel, the electric-leakage detection circuit that resistance R 7 is formed.

The utility model operation principle is: motor starts in the usual way, moves.When the phase failure or motor occurring and overload, short circuit and leaky occur; respectively by each detecting element, judgment component output fault-signal; a process or a door protection outlet circuit remove to trigger the controllable silicon KG1 control utmost point; the KG1 conducting; thereby make relay or mechanical locking device action in the motor rotation control loop; cut off the motor power supply circuits, be unlikely with the protection motor and burn.Adopt the effect that starts power circuit slowly to be, when avoiding motor start-up, starting current surpasses normal 5～7 times of misoperations that caused.

The utility model has the advantages that:

Detecting element in the one, phase failure part is few, and dependable performance, the no matter motor or the three-phase imbalance of which kind of connection, and the motor after the phase failure all can in time be subjected to 100% protection.

Its two, easy to use, do not need debugging, the gear that the user only needs by-pass cock to arrive with power of motor coupling gets final product, and the precision height, can not burn when motor overload, short circuit.

Its three, make things convenient for the user, the existing independent phase failure, overload, short-circuit protector have the phase failure, overload, the short-circuit protector that combine together with A.C. contactor CJ again.And protector is planted in the back, no matter the CJ of which kind of capacity, power consumption is few during its operation; several watts of power consumption zero points only, tripping operation moment power consumption is 3W just also, and existing various commercially available motor protecter; CJ with the 20A capacity is an example, power consumption 9W during operation, and with the CJ capacity of coupling increase and power consumption increase.In addition, the back plants that protector also can be avoided taking place because of those not strong users of protection consciousness because the loss of not adorning motor protecter and being brought.

Its four, produce easily, debugging is simple, cost is lower.

Fig. 1 is the utility model outline drawing;

Fig. 2 is the utility model circuit theory diagrams;

Fig. 3 is a mechanical locking device structural representation of the present utility model.

The utility model is described in further detail below in conjunction with accompanying drawing:

As shown in Figure 1: arc-extinguish chamber 1, shell 2, shell 3 are used bolted successively.The mechanical locking device that A.C. contactor CJ is housed in the shell 2 and moves by the control contact that mechanical arm 16, release are formed.The phase failure, overload, short-circuit protection circuit are housed in the shell 3.On the housing face of shell 3, be provided with power of motor selector switch 4, the overload protection indicator light 5 of adjusting, overload protection are adjusted and are adjusted potentiometer 6 and the phase failure detects indicator light 7.On the shell 2 housing faces, two current transformers 8 are housed, after electric power connection line 9 passed the current transformer cavity in the circuit, its termination linked to each other with arc-extinguish chamber 1 housing by A.C. contactor CJ outlet terminal and hold-down screw 10.Above sequence number 4,5,6,7,8 is respectively K, LED 1, W, LED2, the LH in Fig. 2 circuit.

As shown in Figure 2, circuit of the present utility model comprises electric power loop, starts electric power loop, open-phase protection circuit, overload and short-circuit protection circuit, electric-leakage detection circuit or parts such as door protection outlet circuit and no-voltage trip loop slowly.

The utility model is provided with two kinds of electric motor protecting contactors that combine (see figure 1) together and do not have CJ with A.C. contactor CJ, and except that the former many no-voltage trip loop features, surplus circuit is formed identical.Concrete condition is as follows.

Power circuit: form by three-phase self coupling reducing transformer B and three-phase bridge rectifier Z1, Z2.B coil primary side end head links to each other with A, B, C three-phase power line respectively, and secondary has two groups of taps to join with Z1, Z2 respectively.B provides the voltage of two groups of electric pressures after Z1, Z2 rectification, uses for protection.Z1, Z2 are made up of six diodes respectively.

Slowly start electric power loop: form by three terminal integrated voltage stabilizer SW, capacitor C 1 and C5, resistance R 11, R12 and R13, triode T1 and diode D19.SW imports the anodal and voltage stabilizing didoe DW negative pole of termination Z2, and connects R11, T1 collector electrode and C5 earth terminal through C1; The SW output connects the other end and the SW public land of R13, T1 emitter, R11 respectively through R12, connect the R13 other end, T1 base stage and C5 non-ground-end through the D19 positive pole.

Or door protection outlet circuit: form by D15, D16, D17, divider resistance R14 and R15, controllable silicon KG2 and R17.D15, D16, D17 positive pole connect the KG1 negative pole of T2 collector electrode, overload and the short-circuit protection circuit of open-phase protection circuit, the D18 negative pole of detection of electrical leakage part respectively, and its negative pole is connected to the tie point of R14, R15.R14 other end ground connection.On another termination of R15 KG2 control utmost point G.The KG2 positive pole connects the Z1 positive pole, and KG2 control utmost point G is parallel with stop botton TN through R17 ground connection on the KG2 positive and negative electrode.

Narrate remainder circuit structure among Fig. 2 below in conjunction with the utility model course of work:

One, open phase protection:

Circuit is formed and is comprised DW, LED2, R8, R9, R10, R17 and T2.The DW negative pole connects the Z2 positive pole; The DW positive pole connects R9 and T2 base stage through R8, meets R17 through the LED2 negative pole again.The T2 collector electrode connects the D15 positive pole and through R10 ground connection, the T2 emitter connects the SW output.R9 and R17 other end ground connection.

When DW detection signal (without voltage stabilizing) is higher than the DW puncture voltage, the DW conducting, after R8, R9 dividing potential drop, be added to the T2 base stage, because T2 adopts silicon PNP switching tube, so during the three-phase normal power supply, T2 base stage forward bias, T2 is blocking state, its collector electrode output negative signal, and negative signal is D15 and instead ends partially, or the no positive voltage of door is exported.When certain breaks mutually in the three-phase alternating-current supply; the DW blocking-up; make the T2 base stage be negative bias; the T2 conducting; its collector electrode output positive voltage makes the D15 conducting, removes to trigger KG2 after R14, R15 dividing potential drop, makes the relay or the mechanical locking device action that are serially connected in the motor rotation control loop; cut off major loop CJ, thereby the protection motor does not burn.

Two, overload, short-circuit protection

C2 and full-wave rectifier are parallel on the secondary of the LH that two same polarities link to each other.The lever arm tail end of K switch links to each other with the positive terminal of full-wave rectifier D13, D14, head end then be connected on the T3 base stage on power of motor select circuit to link to each other.The T3 emitter connects on the D16 positive pole through the KG1 negative pole, and meets C3, R6 in parallel through LED1.The T3 collector electrode connects the SW output.C3, R6 other end ground connection.KG1 positive pole, the control utmost point are parallel with R5.

Power of motor selects circuit to be made up of 4 (or＞,＜4) resistance (R1, R2, R3, R4) and adjustable resistance W and R18.Four resistance one ends are connected to W, and the other end is empty, can join with K lever arm head end successively, form power of motor and select gear.The W other end and central point connect the T3 base stage and through R18 ground connection.

LH detects overload, short circuit current signal, after D13, D14 full-wave rectification, drop to R1 or R2 or R3 or R4 and go up (concrete voltage drop value is decided on the value of T3 base stage shutoff voltage critical point), fine setting W, LED1 is in bright, the critical point between putting out, and this moment, the motor running current was adjusted in 1.3 times (1.3 times of electric currents that are considered as transshipping).

When motor normally moves, not conducting of T3 and no-output.When current of electric surpasses 1.3 times and when above, the T3 conducting, C3, C6 pick up counting.If in allowing overload time, overload current disappears, and then KG1 still blocks, the output of fault-free signal.As arrived the permission overload time and also disappeared; then T3 exports fault-signal (positive voltage); after the R5 step-down, trigger the KG1 conducting; so D16 conducting; after R14, R15 dividing potential drop, go to trigger the KG2 conducting; make the relay or the mechanical locking device action that are serially connected in the motor rotation control loop, cut off major loop CJ, thereby the protection motor is not burnt.If it is very fast that overload current rises, then C3 is filled very soon, and the time of cutting off the electricity supply shortens.Therefore, this circuit has the over-load inverse time-lag characteristic, so this circuit has overload and short-circuit protection function concurrently.

Three, earth leakage protective

Form by C4, R7, D18.C4, R7 parallel connection, one end ground connection, the other end meets D17 through the D18 negative pole.

If motor damages because of fixed subcoil insulating and when meeting sb. at the airport shell generation leaky, leakage current enters D17 through C4, R7 step-down, removes to trigger KG2, makes the relay or the mechanical locking device action that are serially connected in the motor rotation control loop, cut off the CJ loop, thereby prevent that the accident of human electric shock from taking place.

As shown in Figure 3, mechanical locking device of the present utility model is positioned at shell 2, and it is made up of mechanical arm 16, release.Mechanical arm 16 be "

" shape, its body of rod middle part relies on fulcrum 17 to be connected on the shell 2; Its left end links to each other with CJ moving contact 15, down is CJ mechanism again, promptly decides contact 14, spring 13, electromagnet 12 and coil 11; Its right-hand member latch arm has a groove for latch 18 cooperations.The release that links to each other with shell 2 inner supports is made up of latch 18, armature 19 and coil 20.Latch 18 tail ends are fixed on armature 19 middle parts.Coil 20(is TQ among Fig. 2) inner chamber is provided with iron core.TQ is serially connected in the no-voltage trip loop.

No-voltage trip loop as shown in Figure 2, the negative pole of TQ one termination KG2 and KG3, another termination C6 and Z1 negative pole, another termination of C6 D20 negative pole, KG3 positive pole and R16, the R16 other end and the KG3 control utmost point are connected to ground, and the D20 positive pole connects the Z1 positive pole.

This mechanical locking device operation principle is: when or door D15, D16, D17 in arbitrary road when having positive voltage to arrive, after R14, R15 dividing potential drop, remove to trigger KG2 control utmost point G, make the KG2 conducting, so TQ gets, iron core adhesive armature 19, make latch 18 head ends break away from mechanical arm 16 grooves, major loop CJ contact disconnects, and motor shuts down; During the TQ dead electricity, iron core magnetic force disappears, and armature resets under spring (not drawing) effect.(press start button HN) when restarting, latch inserts groove again, and so the combination of CJ contact is motor entry into service again.If motor is quit work, as long as press stop botton TN.

Claims

1; a kind of motor protection contactor; its shell is provided with the phase failure in (3); overload; short-circuit protection circuit; it is characterized in that voltage stabilizing didoe DW takes out phase failure voltage signal from the three-phase bridge rectifier Z2 that three-phase self coupling step-down transformer B links to each other; two current transformer LH by the same polarity parallel connection detect overload; the short circuit current signal; this two signal is the triode T2 in open-phase protection circuit respectively; overload; T3 in the short-circuit protection circuit; controllable silicon KG1; transport to or door protection outlet circuit on the control utmost point G of KG2; the KG2 positive pole connects three-phase bridge rectifier Z1 positive pole; the KG2 negative pole links to each other with the motor rotation control loop, the T2 emitter; the T3 collector electrode is connected to and starts slowly in the power circuit on the three terminal integrated voltage stabilizer SW output.

2, contactor according to claim 1; it is characterized in that being equipped with on the shell (3) of the phase failure, overload, short-circuit protection circuit; the shell that useful bolt is attached thereto (2), arc-extinguish chamber (1); shell is provided with A.C. contactor CJ and mechanical locking device in (2); mechanical locking device is made up of mechanical arm (16), release; release is called for short TQ by latch (18), armature (19) and coil 20() form, TQ is serially connected in the no-voltage trip loop, and an iron core is arranged in the TQ cavity.

3, contactor according to claim 2 is characterized in that in the described no-voltage trip loop, the negative pole of TQ one termination KG2, KG3, another termination C6 and Z1 negative pole, another termination of C6 D20 negative pole, KG3 positive pole, and connect the KG3 control utmost point and ground connection through R16, the D20 positive pole connects the Z1 positive pole.

4, contactor according to claim 1 and 2 is characterized in that by in D18 and in parallel capacitor C 4, the electric-leakage detection circuit that resistance R 7 is formed, C4, R7 one end ground connection, the other end through the D18 negative pole with or door protection outlet circuit in the D17 positive pole link to each other.

5, contactor according to claim 1 is characterized in that in the open-phase protection circuit that the DW negative pole connects the Z2 positive pole; the DW positive pole connects R9 and T2 base stage through R8; meet R17 through LED 2 negative poles, R9 and R17 other end ground connection, it is anodal and through R10 ground connection that the T2 collector electrode meets D15.

6, contactor according to claim 1; it is characterized in that in overload, the short-circuit protection circuit; LH secondary two ends also are connected to C2 and full-wave rectifier D13, D14; the lever arm tail end of K switch links to each other with D13, D14 are anodal; head end then be connected on the T3 base stage on power of motor select circuit to link to each other; the T3 emitter through the KG1 negative pole connect or door protection outlet circuit in the D16 positive pole on, connect C3, R6, C3, R6 other end ground connection in parallel through the LED1 negative pole.

7, contactor according to claim 6 is characterized in that resistance R 1, R2, R3, R4 one end are parallel on adjustable resistance W one end in the power of motor selection circuit, and the W other end and central contact link to each other with the T3 base stage.

8, contactor according to claim 1, it is characterized in that starting slowly in the power circuit, the SW output connects R13, T1 emitter, R11 and SW public land through R12 respectively, meet the R13 other end, T1 base stage and C5 through the D19 positive pole, the other end ground connection of C5 and R11 and meet T1 collector electrode and C1, another termination of C1 SW input and DW negative pole.