CN2087786U

CN2087786U - Current-leakage voltage-withstand combined tester

Info

Publication number: CN2087786U
Application number: CN 90215553
Authority: CN
Inventors: 张钧华
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-12-15
Filing date: 1990-12-15
Publication date: 1991-10-30

Abstract

The utility model relates to a current-leakage voltage-withstand combined tester, belonging to the technical field of the testing instrument of insulation resistance. The utility model combines a current-leakage tester and a voltage-withstand tester into one instrument; conversion of two testing states is realized by a switch a plurality of relays; two digital voltmeters are respectively used for displaying the high-voltage magnitude and the magnitude of leakage current of a voltage-withstand test or the magnitude of working voltage and the magnitude of the leakage current of a current-leakage current test. The high-voltage side of a high-voltage transformer is provided with a low-voltage tap; the high-voltage magnitude can be displayed on a digital meter via a high-voltage testing push button; a plurality of luminous tubes are arranged on a panel to indicate the operating state of the instrument of the utility model.

Description

Current-leakage voltage-withstand combined tester

The utility model belongs to the insulation measurement Instrument technology field.

Leakage current is two kinds of different notions with withstand voltage test, and their difference is: leakage current is meant that instrument or equipment etc. are operated under the condition of rated voltage or 1.1 times of rated voltages, cabinet when insulation leakage current over the ground.It has reflected when being connected on instrument on the electrical network, and how whether casing have numb electric situation and degree.Withstand voltage test be meant this instrument within a certain period of time under high-pressure situations (for example general 220 volts of instruments, withstand voltage be 1500 volts 1 minute) ability to bear, the leakage current under high pressure conditions is presented as the size of insulation resistance.Earial drainage and withstand voltage index have all been required for general instrument and equipment.And at present domestic and international leakage current tester and Hi-pot Tester all are separate, and all show reading with pointer reometer or voltage table.Generally also have only the leakage current overload-alarm and do not have the numerical value demonstration for Hi-pot Tester.For electrical equipment factory, must promptly buy Hi-pot Tester and buy leakage current tester again, counter investment will be high like this, and the reading accuracy of the pointer table of existing this instrument is not high.

The purpose of this utility model is that above-mentioned two kinds of surveying instruments are united two into one, and constitutes the withstand voltage comprehensive tester of earial drainage, and to reduce the equipment investment of applying unit, changing pointer ammeter simultaneously is digital ammeter, improves reading accuracy.

Formation of the present utility model is respectively to high-tension transformer or the power supply of earial drainage voltage transformer with an adjustable transformer, show the high tension voltage value of voltage-withstand test state and the operational voltage value and the leakage current values of high pressure leakage current value or leakage current testing state respectively with two electric current and voltage displays, carry out the conversion of two kinds of test modes with a plurality of relays that are contained in the test mode switch on the instrument panel and are contained in the machine.A low pressure tap is arranged in the high-pressure side of high-tension transformer, the principle that is directly proportional with the number of turn according to the transformer secondary voltage, the voltage of low pressure tap can reflect the output high-voltage value of high-tension transformer, simultaneously after the low pressure tap, start the alarm for high voltage circuit, can conveniently reach the high pressure of determining this tester safely and whether produce by a high pressure test button and commutator tube and relay.

Accompanying drawing 1 is an outside drawing of the present utility model;

Accompanying drawing 2 is electrical schematics of the present utility model.

The utility model is described in further detail below in conjunction with drawings and Examples.Label declaration in the accompanying drawing 1 is as follows: 1. adjustable transformer adjusting pressuring knob; 2. power switch; 3. test mode switch; 4. high voltage startup button; 5. high pressure test button; 6. the power supply power supply state switch in the leakage current testing state; 7. electric power polarity switch; 8. ann reset button; 9. high-voltage output end; 10. high tension loop end; 11. high pressure time dalay indicator light; 12. the supply socket that leakage current testing is used; 13. high pressure delay time selector switch; 14. high-voltage and current-limitation selector switch; 15. high pressure output reading pilot lamp; 16. digital voltmeter; 17. alarm for high voltage pilot lamp; 18. leakage current reading pilot lamp; 19. leakage current testing status indicator lamp; 20. leakage current range switch; 21. high pressure output indicator; 22. high pressure leakage current reading pilot lamp; 23. power light; 24. digital voltmeter; 25. leakage current testing operating voltage reading pilot lamp.As shown in Figure 2, energized switch 2, transformer B4 starts working, and power light 23 is bright.In state selecting circuit 28,3 dozens of state selecting switch are pressed high voltage startup button 4, by relay J 5-2 normally closed interlock in the voltage-withstand test position, connect adjustable transformer B1, make relay J 1 action make state selecting circuit 28 self-lockings by relay J 3-1 normally closed interlock simultaneously.Adjustable transformer B1 can be respectively to high-tension transformer B2 or earial drainage voltage transformer B3 power supply by relay contact J5-4.In the high-pressure side of high voltage variable device B2 a low pressure tap is arranged.Can on digital voltmeter 16, show the high tension voltage value by divider resistance 1R1,1W1 in the low pressure tap.Connect a high pressure test button 5 after the low pressure tap, press high pressure test button 5, low-voltage constitutes current return by commutator tube and polarity relay J2, at this moment there is not high impedance load in the current return, electric current is bigger, and the current-limiting resistance in the high-voltage and current-limitation circuit 27 is to the not influence of startup of relay J 2.Relay J 2 actions cause relay J 3 actions, and the action of relay J 3 starts warning circuit 30 on the one hand, and alarm for high voltage pilot lamp 17 is bright, alarm for high voltage news Chinese percussion instrument SP sounding has illustrated high pressure output, on the other hand, dissengaged positions is selected the self-locking state of circuit 28, cutoff high.The method whether this detection high pressure produces is convenient, directly perceived, and safety.When the high pressure detected state, because relay J 2 is polarity relays, the reset button 8 that only pushes for emergency, polarity relay J2 is task again, reports to the police and eliminates.Behind the high voltage startup, between high-voltage output end 9 and high tension loop end 10, connect high impedance load, it is measurand, after the commutator tube rectification, through current-limiting circuit and divider resistance 1R2,1W2 and the high tension loop of 1R3 formation, voltage drop on the divider resistance 1W2 has reflected the value of high pressure leakage current, shows this value on the digital voltmeter 24.Five grades of current limliting selector switch 14 are arranged in high-voltage and current-limitation circuit 27, and cut-off current is selected in 0.5mA, 1mA, 2mA, 5mA, 10mA respectively.In this state, owing to insert high impedance load, voltage drop mainly drops on the high-voltage load, and therefore, at this moment polarized relay J2 is failure to actuate.In state selecting circuit 28, because relay J 1 action and self-locking, cause status display circuit 29 repeat circuit contact J1-2 action, make that high pressure output reading pilot lamp 15 is bright, what expression digital voltmeter 16 showed is the high tension voltage value, unit is a kilovolt, high pressure output indicator 21 is bright, and expression has high pressure output now, and high pressure leakage current reading pilot lamp 22 is bright, what expression digital voltmeter 24 showed is the high pressure leakage current value, and unit is a milliampere.In high pressure delay circuit 26, because the action of relay J 1 causes relay J 1-3 action, this action makes high pressure time dalay indicator light 11 bright on the one hand, and electric capacity 2C1 is by resistance 2R charging simultaneously, when the approaching abundance of electric capacity, amplifier work, the output high level makes transistor turns, relay J 4 actions, relay J 3 actions, warning circuit is reported to the police, high pressure cut-off.Delay selection switch 13 is arranged in high pressure delay circuit 26, discharge and recharge R value in the time constant according to RC, select delay time to be respectively 15 seconds, 30 seconds, 60 seconds, 120 seconds and manual control, when manual shelves, RC time-delay shelves all disconnect, transistor always can conducting, and high pressure is kept always, till manual shelves change time-delay shelves or manual power over to and cut off.In high pressure delay circuit 26, also have a time of fire alarming that constitutes by 2R3,2W5,2R5 to prolong circuit, after this RC delay circuit can make high pressure cut-off, warning news Chinese percussion instrument SP in the alarm for high voltage circuit 30 rings three times, and the alarm for high voltage pilot lamp dodges three times, expression " time arrives ".

When the leakage current testing state, state switch 3 is dialled to the earial drainage shelves from withstand voltage shelves, switch 3 pushes 2 positions from 1 position in state selecting circuit 28, switch 3 pushes 4 positions from 3 positions in warning circuit 30, at this moment relay J 7, J8 action, relay J 5 in the state selecting circuit 28, J6 action, thus make status display circuit 29 and leak each corresponding relay contact action in the sample circuit 31, and this tester becomes the leakage current testing state by withstand voltage state exchange.When the earial drainage test mode, earial drainage current indication pilot lamp 18 in the status display circuit 29 is bright, what expression digital voltmeter 16 showed is leakage current values, earial drainage test mode pilot lamp 19 is bright, the expression instrument is operated in the earial drainage test mode, leakage current testing operating voltage reading pilot lamp 25 is bright, and what expression digital voltmeter 24 showed is earial drainage test job magnitude of voltage.An electric power polarity switch 7 is arranged in state selecting circuit 28, can change the electric power polarity of the supply socket 12 that leakage current testing uses by relay J 6, a power supply state switch 6 is arranged in earial drainage sample circuit 31, the earial drainage testing power supply can be done the conversion of normal power supply or single phase power supply.Also have a leakage current range switch 20 in earial drainage sample circuit 31, range selector 20 is three-pole switch, and by the range of divider resistance change digital voltmeter 16, the scaling position of digital voltmeter 16 is moved backward simultaneously.Consider that leakage current testing is an intermittently used, so the capacity of design leakage current transformer B3 is less than or equal to 1/2nd of measurand capacity, for the sake of security, on earial drainage voltage transformer B3, electrothermal relay J9 has been installed, if transformer is overheated, then electrothermal relay J9 action, warning circuit 30 starts and reports to the police, treat that the transformer temperature reduces, report to the police to imitate and remove that leakage current testing can be proceeded again.

The utility model with withstand voltage test and leakage current testing molten be a machine, can reduce the equipment investment of metrological service, electric equipment products manufacturing enterprise, and the measuring accuracy height, easy to use.

Claims

1, the withstand voltage comprehensive tester of earial drainage, by adjustable transformer B1, high-tension transformer B2, earial drainage transformer B3, electric current and voltage display 16,24 and housing constitute, it is characterized in that adjustable transformer B1 by relay contact J5-4 respectively to high-tension transformer B2 or earial drainage voltage transformer B3 power supply, state selecting circuit 28 is by state selecting switch 3 and many relay contact is constituted, and also has a RC time of fire alarming that is made of 2C3,2W5,2R5 to prolong circuit in high pressure delay circuit 26.

2, tester as claimed in claim 1 is characterized in that electric current and voltage display 16,24, all adopts digital voltmeter.

3, tester as claimed in claim 1 or 2, there is a low pressure tap high-pressure side that it is characterized in that high-tension transformer B2, connect digital voltmeter 16 input ends by divider resistance 1R1,1W1 and relay contact J7-1, the low pressure tap constitutes the low-tension current loop by high pressure test button 5, commutator tube and polarity relay J2.

4, tester as claimed in claim 1 is characterized in that the capacity of earial drainage voltage transformer B3 is less than or equal to 1/2nd of measurand capacity.