CN2351767Y

CN2351767Y - Insulation resistance automatic display device for electric machine

Info

Publication number: CN2351767Y
Application number: CN 99201225
Authority: CN
Inventors: 刘丽娟; 范富荣; 秦保华; 高志勇
Original assignee: ZHONGQUANCHENG ELECTRONIC CO Ltd TIANJIN
Current assignee: ZHONGQUANCHENG ELECTRONIC CO Ltd TIANJIN
Priority date: 1999-02-02
Filing date: 1999-02-02
Publication date: 1999-12-01
Anticipated expiration: 2009-02-02

Abstract

The utility model relates to an insulation resistance automatic display device for electric machines, which is used for measuring the bale of the electric machine and a resistance value between iron cores. The power circuit of the utility model is composed of a transformer T, and a voltage stabilizing circuit is composed of a three-terminal voltage stabilizing block IC< 1 >; a time delay circuit is composed of a time-base circuit block IC< 2 >, and a test circuit is composed of a test table I; an executive circuit is composed of two relays J and J< 1 >, and a protective circuit is composed of a relay J< 2 >; a lamp circuit is composed of lamps L< 1 > and L< 2 >. The utility model has the advantages of conveniently measuring the insulation value of the electric machine at any moment, no need of dismounting the electric machine during detection and enabling the down time of the electric machine as little as possible.

Description

Electrical machine insulation resistance automatic display

The utility model relates to the proving installation of electrical machine insulation resistance.

The application of motor is very widely, and people need regular or irregular insulating resistance value to motor to detect in order to guarantee the normal operation of motor usually.During detection, operating personnel need motor and operating circuit disconnection just can be carried out, and the measurement of the insulating resistance value of heavy-duty motor and fire proof motor is more difficult.Measure for insulating resistance value, not only will shut down, and increased many complicated operations, even take motor apart these motors.Therefore very inconvenient, and, in commercial production, measurement to electrical machine insulation resistance also is not omissible, if detect untimelyly, it is unreliable that in a single day the line bag of motor and the shell of motor insulate, gently then can burn motor, heavy then can cause the accident, bring serious loss to production.Therefore, people wish to have a kind of automatic measurement display device of electrical machine insulation resistance, the insulation resistance of testing and demonstrate motor easily that can be at any time, and the time that motor is shut down is few as much as possible.

The purpose of this utility model is to provide a kind of automatic testing equipment of electrical machine insulation resistance, can measure automatically electrical machine insulation resistance, and need not make any preliminary work.When need measuring, as long as press the motor stop botton, treat that motor stops inertia and rotates after, this display shows automatically by the insulating resistance value of measured motor, after having surveyed, presses the start button again, motor recovery normal operation, this display quits work immediately.Therefore can be compressed to the stop time of motor minimumly, and simple to operation, can measure the insulation resistance of motor at any time.

The purpose of this utility model is achieved in that

A kind of electrical machine insulation resistance automatic display is used to measure the line bag of motor and the resistance value between iron core, mainly is made of power circuit, rectification circuit, mu balanced circuit, delay circuit, test circuit, executive circuit; It is characterized in that:

Described power circuit is made of transformer T, and the tap 1 of the elementary winding of transformer T is connected with post head N, and tap 3 is connected with binding post P through fuse F1, switch SW 1; Secondary winding of transformer is connected with the input end of rectification circuit;

Rectification circuit is interconnected to full-wave rectification bridge by diode D1, D2, D3, D4 and constitutes; Input end Z1, the Z2 of this rectifier bridge is connected with the

tap

9,6 of the secondary winding of transformer T respectively; The output terminal of rectifier bridge is Z3, Z4; Z3 is the earth potential output terminal, and Z4 is the positive potential output terminal;

Mu balanced circuit is made of three-terminal voltage-stabilizing ic chip 1, and the pin one of IC1 is connected with the Z4 of rectifier bridge end; The pin 3 of IC1 is connected with the Z3 of rectifier bridge end; The pin two of IC1 is an output terminal;

Delay circuit is by time base circuit ic chip 2, resistance R 2, R3, R4, and capacitor C 4, inductance L and selector switch SW2 constitute; The pin one of ic chip 2 is connected with earth potential; The pin 4,8 of IC2 is connected with the pin two of IC1; The pin 3 of IC2 is a signal output part; One end of resistance R 2 is connected with the pin two of IC1, other end resistance in series R3, the R4 of R2, capacitor C 4 back earthing potentials; Inductance L one end is connected on the contact between resistance R 4 and the capacitor C 4, and the other end of L is connected with earth potential through resistance R 5, capacitor C 5; The moving contact 4 of selector switch SW2 is connected with the pin two, 6 of IC2; The stationary contact 1 of SW2 is connected on the contact between resistance R 2 and the R3, and the stationary contact 2 of SW2 is connected on the contact between resistance R 3 and the R4; The moving contact 4 of SW2 also is connected on the contact between resistance R 4 and the capacitor C 4;

Test circuit is made of test chart I, and the positive potential input end V+ of I is connected with the pin two of IC1 through fuse F2; The negative potential input end V-earthing potential of I; The test anode L of I is connected with binding post mL through resistance R 8; The test negative terminal E of I is connected with binding post mE through resistance R 7;

Executive circuit is made of relay J, J1, and coil one end of relay J is connected with the pin 3 of IC2, and the other end of the coil of J is connected with the pin two of IC1; Behind the coil of the normally opened contact J-1 series relay J1 of relay J, be connected between the tap 1 and tap 3 of the elementary winding of transformer T; The normally opened contact J1-1 of relay J 1 is connected between the test anode L and binding post mL of test chart I; The normally opened contact J1-3 of relay J 1 is connected between the test negative terminal E and binding post mE of test chart I.

It also is provided with holding circuit, and this holding circuit is made of relay J 2, and the coil of relay J 2 is connected between the tap 1 and tap 3 of elementary winding of transformer T; The normally closed contact J2-1 of relay J 2 is in parallel with the branch road of capacitor C 5, resistance R 5.

It also is provided with lighting circuit, and lighting circuit is made of bulb L1 and L2, and bulb L1 is connected between the secondary winding tap 6 and tap 8 of transformer T, and bulb L2 is in parallel with L1.

The model of ic chip 1 is 7812, and the model of ic chip 2 is 555, and the model of test chart I is PC32-3.

The utility model has following positive beneficial effect:

1. the utility model is connected the outside of motor, and measuring junction only is connected with motor housing with motor power supply live wire; Need not dismantle motor during measurement, make the stop time of motor few as much as possible.

2. the utility model utilizes relay to control the test lead of test chart and being electrically connected by measured motor; And be provided with delay circuit and holding circuit; Therefore when motor rotation, this display does not detect, when the motor stall, time-delay through tens seconds, this display enters the measurement show state automatically, and when motor restarted, this display stopped to measure demonstration immediately, therefore realized automatic test, can measure the insulating resistance value of motor at any time easily motor.

Now in conjunction with the accompanying drawings the utility model is described in further detail as follows with preferred embodiment:

Fig. 1 is circuit theory diagrams of the present utility model;

Fig. 2 is the control circuit that prior motor starts and stops;

Fig. 3 is the utility model user mode reference diagram.

Electrical machine insulation resistance automatic display of the present utility model, can measure the insulating resistance value of motor, just can measure the line bag of motor and the resistance value between iron core, under normal circumstances, resistance value should be very big between the line bag of motor and iron core, and promptly line bag and iron core insulate, otherwise motor will damage, or burnt, therefore, in commercial production, should often measure the insulating resistance value of motor.

See also Fig. 1, power circuit of the present utility model is made of transformer T, the elementary winding of transformer T and secondary winding all are many taps windings, this is because line voltage is generally 660V, 380V, 220V, 127V in commercial production, so the utility model is to there being a plurality of taps, to mate with electrical network.Mu balanced circuit is made of three-terminal regulator block 7812, delay circuit is made of time base circuit piece 555,555 are connected into the timer working method in this circuit, its time regularly is by pin two, the size decision of the threshold voltage of 6 inputs, after this device starts, the voltage stabilizing of the pin two output of IC1 is by resistance R 2, R3, R4 is to capacitor C 4 chargings, voltage when capacitor C 4 two ends reaches the IC2 pin two, during the threshold voltage of 6 ends, and the IC2 conducting, the pin 3 of IC2 becomes electronegative potential, electric current can be imported, relay J action, the pin two of IC2, the threshold voltage of 6 inputs is from resistance R 2, R3, the intrinsic standoff ratio of R4, therefore can change pin two by the moving contact that changes switch SW2,6 threshold voltage has also just changed the delay time of timer.Executive circuit is made of relay J and J1, after the timing of timer has arrived, the pin 3 of IC2 becomes electronegative potential, electric current just can flow into, and the coil of relay J gets electric, its normally opened contact J-1 closure, and then relay J 1 coil gets, the J1-1 closure, the J1-3 closure, test chart I can test.

See also Fig. 2, Fig. 2 is existing modal electric motor starting and the control circuit that stops, C is an A.C. contactor among the figure, contact Ca, Cb, Cc is three normally opened contacts of C, be connected on live wire A respectively, B, on the C, M is a motor, and N is a zero line, Co also is the normally opened contact of C, when pressing the button a, the coil of A.C. contactor C gets electric, its normally opened contact Ca, Cb, the Cc closure, three-phase firewire A, B, C powers to motor M, motor M starts, and Co is also closed simultaneously, with button a self-locking, if motor M is stopped, only need press the button b, the coil losing electricity of A.C. contactor C at this moment, its normally opened contact Ca, Cb, Cc opens, three-phase firewire A, B, C and motor M disconnect, and motor M stops.Contact CL is the normally closed contact of A.C. contactor C, and the spare time extremely need not generally speaking.

See also Fig. 3, when the utility model uses binding post P is electrically connected with a live wire of motor M by the normally closed contact CL of A.C. contactor C, its tie point is between any normally opened contact of electrical network and A.C. contactor C, be between A and the Ca, between B and the Cb or between C and the Cc, be between C and the Cc among this figure.Post head N is connected with the zero line N of motor M.Binding post mL is electrically connected with a live wire of motor M, and its tie point is between the arbitrary normally opened contact and motor M of A.C. contactor C, and promptly between Ca and the M, between Cb and the M or between Cc and the M, this figure is between Cc and the M.Binding post mE is electrically connected with the shell of motor M.

Principle of work of the present utility model is as follows:

Closing Switch SW1, line voltage are added on the elementary winding of transformer T, and after transformer T step-down, the low-tension current of the secondary winding of T output becomes Rectified alternating current after the rectifier bridge rectification; Again after three-terminal regulator block 7812 voltage stabilizings, by 7812 the pin two output DC resistance R 2 of flowing through, R3, R4 is to capacitor C 4 chargings, rise to the pin two of IC2 when the voltage at capacitor C 4 two ends, during 6 required threshold voltages, the IC2 conducting, the pin 3 of IC2 becomes electronegative potential, electric current just can be imported, and the time that capacitor C 4 chargings are boosted is delay time, when the pin 3 of IC2 becomes electronegative potential, the coil of relay J gets, its normally opened contact J-1 closure, the coil of relay J 1 gets electric, its normally opened contact J1-1, the J1-3 closure, test chart I just can measure the live wire of motor M and the resistance value between shell, and is presented on the instrument display window.Because of the live wire of motor links to each other with the line bag, the shell of motor links to each other with iron core, so measure the resistance value of the live wire and the shell of motor, also just measures the resistance value of motor lines bag and iron core, has promptly measured the insulating resistance value of motor.

Delay circuit is set is because the motor that has during test turns round, when pressing motor stop button b, though the live wire of motor M is cut off, but motor is because inertia also can rotate for a moment, and at this moment motor M is equivalent to a generator, if connect test chart I this moment, the electric current that motor M is sent can pour in down a chimney into test chart I, and instrument is damaged, therefore will be through after the IC2 time-delay, connect test chart I again, test, when restarting motor M, in case press the button a, the coil of A.C. contactor C just, its normally closed contact CL just opens, and cuts off the power circuit of this display, has also just disconnected being electrically connected of motor M and test chart I.

Holding circuit is made of relay J 2, during Closing Switch SW1, because of the coil of relay J 2 gets; its normally closed contact J2-1 opens; so the electric charge on the capacitor C 4 does not bleed off, the last maintenance of C4 higher voltage is greater than the IC2 pin two; 6 threshold voltages that require; 3 pin of IC2 have electric current to flow into, and the coil of relay J gets electric, its normally opened contact J-1 closure; the coil of relay J 1 gets; its normally opened contact J1-1; the J1-3 closure, test chart I is in test mode, if people's close push button a starter motor M is arranged this moment; because of the coil of A.C. contactor C gets; its normally closed contact CL disconnects, the coil losing electricity of relay J 2, and normally closed contact J2-1 connects; at this moment; capacitor C 4 is passed through L; normally closed contact J2-1 discharge, the L impedance is very little, and the electric current on the capacitor C 4 can bleed off immediately; the coil losing electricity of relay J; J-1 opens, the coil losing electricity of relay J 1, J1-1; J1-3 opens, and test chart I is disconnected with being electrically connected immediately of motor M.Reached the purpose of protection test chart I.Thereby when having accomplished motor rotation, test chart I does not test.After the motor stall, test chart I enters test mode through time-delay, and when treating that motor restarts, test chart I stops test immediately.Realized automatic working method, therefore simple to operate, can test motor easily at any time, during test, need not dismantle motor, make the stand-by time of motor be compressed to minimum.

Lighting circuit is made up of bulb I1, L2, and L1, L2 are that the display window for test chart I provides illumination, and the display window of test chart I also can be seen clearly in dark surrounds.

Claims

1. an electrical machine insulation resistance automatic display is used to measure the line bag of motor and the resistance value between iron core, mainly is made of power circuit, rectification circuit, mu balanced circuit, delay circuit, test circuit, executive circuit; It is characterized in that:

Rectification circuit is interconnected to full-wave rectification bridge by diode D1, D2, D3, D4 and constitutes; Input end Z1, the Z2 of this rectifier bridge is connected with the tap 9,6 of the secondary winding of transformer T respectively; The output terminal of rectifier bridge is Z3, Z4; Z3 is the earth potential output terminal, and Z4 is the positive potential output terminal;

Delay circuit is by time base circuit ic chip 2, resistance R 22, R3, R4, and capacitor C 4, inductance L and selector switch SW2 constitute; The pin one of ic chip 2 is connected with earth potential; The pin 4,8 of IC2 is connected with the pin two of IC1; The pin 3 of IC2 is a signal output part; One end of resistance R 2 is connected with the pin two of IC1, other end resistance in series R3, the R4 of R2, capacitor C 4 back earthing potentials; Inductance L one end is connected on the contact between resistance R 4 and the capacitor C 4, and the other end of L is connected with earth potential through resistance R 5, capacitor C 5; The moving contact 4 of selector switch SW2 is connected with the pin two, 6 of IC2; The stationary contact 1 of SW2 is connected on the contact between resistance R 2 and the R3, and the stationary contact 2 of SW2 is connected on the contact between resistance R 3 and the R4; The moving contact 4 of SW2 also is connected on the contact between resistance R 4 and the capacitor C 4;

2. electrical machine insulation resistance automatic display as claimed in claim 1, it is characterized in that: it also is provided with holding circuit, and this holding circuit is made of relay J 2, and the coil of relay J 2 is connected between the tap 1 and tap 3 of elementary winding of transformer T; The normally closed contact J2-1 of relay J 2 is in parallel with the branch road of capacitor C 5, resistance R 5.

3. electrical machine insulation resistance automatic display as claimed in claim 1, it is characterized in that: it also is provided with lighting circuit, and lighting circuit is made of bulb L1 and L2, and bulb L1 is connected between the secondary winding tap 6 and tap 8 of transformer T, and bulb L2 is in parallel with L1.

4. electrical machine insulation resistance automatic display as claimed in claim 1 is characterized in that: the model of ic chip 1 is 7812, and the model of ic chip 2 is 555, and the model of test chart I is PC32-3.