CN201955396U

CN201955396U - Ground measuring display instrument

Info

Publication number: CN201955396U
Application number: CN2009201331877U
Authority: CN
Inventors: 李英岱
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-07-02
Filing date: 2009-07-02
Publication date: 2011-08-31
Anticipated expiration: 2019-07-02

Abstract

The utility model relates to a simple electric device capable of detecting and displaying ground impedance and testing the electrical performance parameters of other parts. The simple electric device adopts the following technical scheme that: a transformer is connected to a 220V main circuit through a voltage division resistor, an electric signal is obtained for the second time, and then a measuring instrument is connected to realize the function of ground impedance as well as voltage and current display; a changeover switch is arranged on the main circuit, one end of the changeover switch is connected with a primary terminal of a convertor, and the other end of the changeover switch is connected with a neutral wire and an earth wire respectively. A test button is connected to three auxiliary circuits between a phase wire and the earth wire through a test resistor, a test variable resistor W1 is connected below a public node of the main and auxiliary circuits, and the other end of W1 is connected with the earth wire. The changeover switch is also connected to a wire incoming end of a power supply to achieve phase-zero conversion.

Description

Ground connection survey shows instrument

Technical field the utility model is that a kind of energy detects, shows that impedance ground also can be to the simple and easy electrical installation of other part electric property parameter testings.

Background technology is along with the progress in epoch, and is human more and more higher to the requirement of Electrical Safety.Therefore be very necessary to frequent detection of the security of office electricity consumption and household electricity and temporary electricity.Particularly office, the moist place of household electricity, the temporary electricity of working-yard and the detection of electrical equipment installation work etc.Good earth then is the important measures of safety utilization of electric power.Now the ground state of operation electrical equipment show mostly be phase, between connect a divider resistance, adopt LED luminotron or neon bulb to show, or utilize the high impedance A.C. voltmeter to show.But the main function of these methods is to show or judge to have or not ground connection, differentiates for the size of impedance ground is then difficult; Or (generally more than thousands of Europe) high impedance A.C. voltmeter just can show when having only impedance ground big.When impedance ground kilo-ohm below the time, these methods can not judge all whether impedance ground qualified.And utilize some other accurate measurement instrument such as earth resistance tester or multifunctional tester to carry out regular detection, some inconvenient parts are all arranged.Play the auxiliary earth rod as needs, can not on-line testing or the like.Therefore it is also not too convenient to carry out regular test with these instrument.

Summary of the invention the utility model provides a kind of electrical installation, and it does not need other auxiliary test units, and energy on-line testing does not simultaneously influence the electricity consumption in other loops, only needs to be inserted into the individual event Three-hole socket during detection and gets final product.When power supply has electricity, push testing button, on instrument, just can know whether the size and the ground connection that demonstrate impedance ground is qualified.Measuring current can according to circumstances be adjusted, and can guarantee that the earth leakage protective device definite value is that 30 milliamperes and 15 MAHs all do not trip.This instrument also has functions such as phase place demonstration, earth leakage protection tripping operation performance test, circuit or the small leakage tests of electrical equipment, line conduction test, electric current and voltage demonstration.

The purpose of this utility model is achieved in that on the 220V major loop, inserts transformer through divider resistance, obtains an electric signal at secondary, inserts measurement instrument, is grounded impedance and voltage, electric current Presentation Function; A switch is arranged on major loop, and terminal of his end and transducer is connected, and the other end can be connected respectively with zero, ground wire through conversion.Insert test button through test resistance on three subsidiary loops between phase line and the ground wire: button 1 connects the impedance ground test loop that R4 is 12MA; Button 2 connects the impedance ground test loop that R5 is 24MA; Button 3 connects the earth leakage protective device trip test loop that R6 is 32MA.Insert 1 kilo-ohm of test variable resistance W1 below the common node in main pair loop, the other end of test resistance links to each other with ground wire.When switch is connected with zero line, can measure loop voltage; When switch is connected with ground wire, energy measurement phase line-to-earth voltage; Measuring instrument on the secondary circuit will be connected in series an adjustable resistance W2.Before the test impedance ground,, make pointer refer to position at 500MA by fine setting W2.(after test finishes, again with the W2 return-to-zero position, with test voltage.) whether pressing

detection button

1 or 2 can to detect impedance ground qualified or show the size of impedance ground.Press test button 1 or button 2 during detection and (during earth leakage protective device definite value 15MA, push AN1, during earth leakage protective device definite value 30MA; push AN2); inject to detect electric current to ground loop, make earthing potential and voltage-to-ground along with the size of impedance ground respective change, thereby realize the purpose of detection.It is low to test a loop precision, and test secondary circuit precision can improve nearly one times.When impedance ground hour (below general kilo-ohm), the variation of pointer and impedance ground linear approximate relationship.Push test button and carry out ground connection when detecting, stake resistance is greater than 4 ohm, and the microampere meter pointer then has slight swing, and impedance ground is bigger, and the beat of pointer is bigger, the size that can read impedance ground according to pointer indicating position.

This instrument can also detect also earth leakage protective tripping operation performance can judge that the loop has or not small electric leakage.The earth leakage protection tripping operation is tested by button AN3.Push the tripping operation of AN3 earth leakage protective device, illustrate that the earth leakage protective device definite value is accurate, trip(ping) circuit is intact.Have or not electric leakage then by push AN1 and AN2 carry out ground state when detecting earth leakage protection whether trip and judge: push the tripping operation of AN1 earth leakage protection; when the protection definite value is 15MA; illustrate that the inaccurate or circuit of earth leakage protective device definite value has extremely slightly electric leakage; if protection definite value 30MA illustrates that then the electric leakage of circuit or equipment is near 20MA.Should search reason this moment, reruns after fixing a breakdown, and can check erroneous ideas at the outset like this.If during protection definite value 30MA, push the tripping operation of AN2 earth leakage protection, illustrate that the inaccurate or circuit of earth leakage protective device definite value has extremely slightly leaks electricity.Phase place shows by three emitting bulbs: LED and neon lamp 1 are bright correct; LED is zero mutually wrong with neon lamp 2 bright explanations; Neon lamp 1 is wrong mutually with neon lamp 2 bright explanations; Three lamps do not work entirely and illustrate that power supply does not have; Have only the LED lamp bright, illustrate to lack ground wire; Have only neon lamp 1 bright, illustrate to lack zero line; Have only neon lamp 2 lamps bright, zero mistake and scarce zero line mutually is described, or wrong mutually and scarce ground wire.Also insert a switch at power inleting terminal, can realize zero conversion mutually.When phase, zero wiring error, can carry out earthing test equally by switch transition.The outside drawing embodiment of this utility model such as figure five, six, seven.

Description of drawings Fig. 1 is the elementary diagram that this utility unit adopts 500 μ A DC ammeter;

Fig. 2 is the elementary diagram that adopts A.C. voltmeter;

Fig. 3 adopts monolithic processor controlled intelligent connection principle block diagram;

Fig. 4 is the connection principle block diagram that utilizes the test of industrial computer telemechanical;

Fig. 5 is the panel figure of this utility unit, and the resistance mark is pressed 12MA measuring current mark;

Fig. 6 is the rear view of this utility unit;

Fig. 7 is the side view of this utility unit;

The principle of embodiment utility model and particular circuit configurations and working condition are provided by following embodiment and accompanying drawing.

Embodiment one: shown in accompanying drawing one, this device primary circuit comprises a fuse FU (0.125A), 4 dropping resistor R1, R2, R3, R7 (R1 is 110K Ω, and R2, R3, R7 are 220K Ω).3 test resistance R4, R5, R6 (being respectively 19.1K Ω, 9.53K Ω, 7.15K Ω) make the electric current of test loop be about 12 milliamperes, 24 milliamperes and 32 milliamperes respectively, and AN1, AN2 are the ground resistance test button, and AN3 is an earth leakage protection trip test button.2 switch K1, K2, K1 is zero switch mutually, K2 is zero ground switch.Normal K1 connects phase line, and K2 connects zero line.An adjustable resistance W1 (1K Ω).W1 is the variable resistor that is used to test, zero setting at ordinary times.A LED lamp and 2 neon bulbs are used for judging phase place.L is and the transformer of the 220V/3.2V of R7 series connection that secondary inserts the microampere meter of one 500 μ A through step-down rectifier filtering.The dial scale of Displaying Meter has increased the scale of voltage and resistance shown in figure six, microampere meter graticule scale still is used for electric current and shows that voltage and resistance scale are drawn by actual measurement.

Plug is inserted the single-phase three-hole socket, and LED lamp and neon lamp 1 are bright, illustrate that phase place is normal.Turn on the power switch K1, open K2 again, check whether voltage V is normal, no abnormally then forward K2 to ground wire, the ground connection table promptly indicates voltage-to-ground V1.At this moment just can judge tentatively by the size that compares V1 and V whether the anti-resistance of ground connection is normal.V1 was more than or equal to V when ground connection was qualified, otherwise stake resistance is defective.For further whether the test impedance ground is normal, adjust variable resistor W1 to maximal value, push AN1, gauge pointer should be indicated on 1K, illustrates that the detection loop is normal.Then W1 is returned zero, push AN1 this moment again, and pointer is motionless, illustrates that impedance ground is qualified.If the beat of pointer, the then size that can judge impedance ground according to the size and the reading of the beat of pointer.If the earth leakage protection definite value is 30MA, can push the AN2 test again, to improve precision, further examine ground state.

Plug is inserted the single-phase three-hole socket, and LED lamp and neon lamp 1 are bright, illustrate that phase place is normal.Turn on the power switch K1, open K2 again, check whether voltage V is normal, no abnormally then forward K2 to ground wire.For test electric leakage and earth leakage protective situation, W1 is returned zero.If the earth leakage protection definite value is 15 milliamperes, push AN1 (12MA) this moment, and earth leakage protection does not trip, and the ground loop leakproof is described; If press AN2 (24MA), the earth leakage protection tripping operation illustrates that the earth leakage protective device trip(ping) circuit is normal.If the earth leakage protection definite value is 30 milliamperes, push AN2 this moment, and earth leakage protection does not trip, and the ground loop leakproof is described.If press AN3 (32MA), the earth leakage protection tripping operation illustrates that earth leakage protective device is normal.

Plug is inserted the single-phase three-hole socket, and LED lamp and neon lamp 2 are bright, and zero mistake mutually is described.The anti-phase K1 that turns on the power switch receives ground wire with K2 again, can detect the state of stake resistance.

Plug is inserted the single-phase three-hole socket, and neon lamp 1 and neon lamp 2 are bright, and mistake mutually is described, turn on the power switch K1, with K2 ground connection, also can test.

Embodiment two: shown in figure two, utilize to connect one behind the transformer L isolated buck and exchange instrument, then form the another kind of ground connection detector that detects usefulness.

Embodiment three: shown in figure three, with different voltages or the current value of test button before and after pushing, sample respectively and carry out A/D conversion back input single-chip microcomputer, can carry out intelligence test by programming.

Embodiment four: shown in figure four, but remote detection.5,6 and 7,8 nodes of

button

1,2 are changed into the relay node of microcomputer telecontrol.

Secondary current is that non-linear decline significantly improves the precision that detects impedance to realize thereby this device has utilized the input of transformer primary voltage to reduce.Make full use of existing electrical instrumentation simultaneously, do not changed its reason structure and performance, only on dial plate, increased some scale values, can increase a kind of new Presentation Function of instrument.This principle of device and simple in structure has wide range of applications, and to important security appliance performance, can make things convenient for and detect and with machine testing.Work about electric power personnel and user be the ground connection and the electric leakage situation of check circuit or electric equipment at any time, thus use consumer that can be relieved.The work about electric power personnel carry ground connection table, for the reliability of checking operational outfit, safety, the electric equipment of checking the building site electricity consumption inerrancy are installed and all have conveniently, succinct, obviously effect reliably.Use it to detect simultaneously, can accomplish to see what is coming from one small clue, take precautions against in advance, and can provide in a large number information accurately for maintenance for small potential safety hazard.It will be work about electric power personnel and huge numbers of families, a kind of new security appliance testing tool is provided, thereby the security appliance prevention work is fulfilled.

Claims

1. simple and easy electrical installation that can detect, show impedance ground, can detect effectively whether impedance ground is qualified, the size of impedance ground, it is characterized in that: on the 220V major loop, insert transformer through divider resistance, obtain an electric signal at secondary, insert electrical equipment Displaying Meter or smart machine, be grounded testing impedance; A switch is arranged on major loop, and its end is connected with transformer terminal, and the other end can be connected respectively with zero, ground wire through conversion; Insert test button through test resistance on three subsidiary loops between phase line and the ground wire; Insert a test variable resistance below the common node in main pair loop, the other end of test resistance links to each other with ground wire; Also insert a switch at power inleting terminal, can realize zero conversion mutually.