CN207964948U - A kind of earth resistance tester - Google Patents
A kind of earth resistance tester Download PDFInfo
- Publication number
- CN207964948U CN207964948U CN201721929807.9U CN201721929807U CN207964948U CN 207964948 U CN207964948 U CN 207964948U CN 201721929807 U CN201721929807 U CN 201721929807U CN 207964948 U CN207964948 U CN 207964948U
- Authority
- CN
- China
- Prior art keywords
- circuit
- test
- resistance
- power supply
- connects
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model discloses a kind of earth resistance tester.Earth resistance tester is using the L phase lines of the power supply system at ground connection to be measured, N zero curves, PE ground wires, the monitoring measurement ground connection dotted state to be measured under conditions of not using auxiliary line.Earth resistance tester includes：Test circuit；Positive input terminal connects L phase lines, and negative input end connects the test power supply of N zero curves；Positive input terminal connects L phase lines, and negative input end connects the test regulated power supply of PE ground wires.Test circuit includes：Control circuit；Under the Pulse Width Control of pulse output end, the reference pulse for providing constant current output provides circuit；The output for the positive output end for testing power supply is converted to the exchange constant current output for injecting earth point to be measured by exchange constant current output circuit under the control of reference pulse；Two sample circuits sample N zero curves respectively and PE ground wires obtain sampled voltage, and are sent into a pair of of differential input end, and control circuit is made thus to obtain the potential difference between N zero curves and PE ground wires.
Description
Technical field
The utility model is related to a kind of grounding monitor apparatus field more particularly to a kind of earth resistance testers.
Background technology
In distribution system, system earth is the most key safety measure.At present using the side of period Site Detection
Method is safeguarded, is passed through the connection state laid interim auxiliary earth polar measurement of Grounding Resistance value and estimate ground path when detection, is judged
Whether earthed system closes rule.Two line measurements as shown in Figure 1, tester form survey by testing connecting line, earthing pole, the earth
Circuit is measured, the ground resistance of earth point to be measured is measured.
Invention content
It can not adopted using the L phase lines of Devices to test, N zero curves, PE ground wires the purpose of this utility model is to provide a kind of
The ground state of earth point to be measured and the earth resistance tester of grounding resistance are measured with monitoring under conditions of auxiliary line.
The utility model is realized using following technical scheme：A kind of earth resistance tester comprising：
Test circuit is used to test the potential difference between the N zero curves of Devices to test and PE ground wires；
Power supply circuit is tested, positive input terminal connects the L phase lines of Devices to test, and negative input end connects N zero curves；And
Regulated power supply is tested, positive input terminal connects L phase lines, and negative input end connects PE ground wires；
Wherein, the test circuit includes：
Control circuit, with pulse output end, a pair of of differential input end；
Reference pulse provides circuit, two input terminal is separately connected the test positive output end of power supply circuit and described
Test the positive output end of regulated power supply；The reference pulse provides circuit under the Pulse Width Control of pulse output end, provides constant current
The reference pulse of output；
Constant current output circuit is exchanged, input terminal connects the positive output end of the test power supply circuit, the exchange constant current
Output circuit is converted to injection under the control of the reference pulse, by the output of the positive output end of the test power supply circuit and waits for
Survey the exchange constant current input of ground terminal；And
Two sample circuits sample N zero curves respectively and PE ground wires obtain corresponding sampled voltage, and it is right to be respectively fed to this
Differential input end makes the control circuit thus obtain the potential difference between N zero curves and PE ground wires.
As being further improved for said program, the test circuit further includes two filter circuits, two sampled voltages
Respectively by being re-fed into this to differential input end after the filtering of described two filter circuits.
As being further improved for said program, the test power supply circuit includes：
Resistance R1, one end connect L phase lines；
Diode D1, anode connect the other end of resistance R1, and cathode connects the reference pulse and provides circuit simultaneously
Constant current output circuit is exchanged with described；
Capacitance C1, one end connect the cathode of diode D1, and the other end connects N zero curves；And
Resistance R3 is connected in parallel on capacitance C1.
As being further improved for said program, the test regulated power supply includes：
Resistance R2, one end connect L phase lines；
Diode D2, anode connect the other end of resistance R2, and cathode connects the reference pulse and provides circuit；
Capacitance C2, one end connect the cathode of diode D2, and the other end connects PE ground wires；And
Zener diode Dz1, cathode connect the cathode of diode D2, and anode connects PE ground wires.
As being further improved for said program, the reference pulse provides circuit and includes：
Resistance R4, one end connect the test power supply circuit；
Photodiode OP1, anode connect the other end of resistance R4, and cathode connects pulse output end, collector
The test regulated power supply is connected, emitter connects the exchange constant current output circuit.
As being further improved for said program, the exchange constant current output circuit includes：
Resistance R8, one end connect the test power supply circuit；
Junction field effect transistor J1, collector connect the other end of resistance R8, and base stage connects the reference pulse
Circuit is provided；And
Resistance R5, one end connect the reference pulse and provide circuit, and the other end connects junction field effect transistor J1
Emitter and form exchange constant current output end OUT, the exchange constant current output end OUT connection PE ground wires simultaneously access described to be measured
Earth point.
As being further improved for said program, the earth resistance tester further includes the display for connecting control circuit
Device.
As being further improved for said program, the earth resistance tester further include connect control circuit operation by
Button, assigning instruction to the control circuit by the operation button makes pulse output end export pulse；And/or the ground connection
Resistance monitor further includes the telecommunication circuit for connecting control circuit, and instruction is assigned to the control circuit by the telecommunication circuit
Pulse output end is set to export pulse.
The utility model also provides a kind of grounding monitor method, is applied to the ground resistance inspection described in any one of the above
It surveys in instrument comprising following steps：
The reference pulse provides the level being electrically connected on the positive output end of the test regulated power supply described in
Regulated power supply is tested to stablize in a steady state value；
The reference pulse provides circuit under the Pulse Width Control of pulse output end, provides the reference pulse of constant current output；
Under the control of the reference pulse, form exchange constant current output injection the earth is the exchange constant current output circuit
The earth point to be measured of Devices to test；
The electric current of the fixed frequency and size of injecting the earth flows back through PE ground wire-N zero curves all the way, to be measured is connect through described all the way
The ground terminal-of distribution end described in the place-earth point to be measured to the line resistance Rg- between the ground terminal of the distribution end of Devices to test
N zero curves flow back；
Through two sampling circuit samples, this of input control circuit obtains N zero curves to differential input end by Differential Input
Potential difference between PE ground wires, to calculate " PE ground wire-N zero curves " and " earth point-earth point to be measured to be measured
To between the ground terminal of the distribution end of Devices to test line resistance Rg- described in distribution end ground terminal-N zero curves " resistance value.
As being further improved for said program, when PE ground wires disconnect, the grounding monitor method be changed into L phase lines and
Two collimation methods of N zero curves go to measure the ground resistance of the Devices to test, read grounding resistance in real time.
The utility model can be supervised using the L phase lines of Devices to test, N zero curves, PE ground wires under conditions of not using auxiliary line
The ground state of Devices to test is measured, and when PE ground wires break, grounding monitor can be changed into two line measurements ground connection electricity
Resistance, reads grounding resistance in real time.
Description of the drawings
Fig. 1 is system earth Site Detection method schematic diagram in current distribution system.
Fig. 2 is the structural schematic diagram for the earth resistance tester that the utility model embodiment provides.
Fig. 3 is the circuit diagram of earth resistance tester in Fig. 2.
Fig. 4 is the grounding monitor method schematic diagram of earth resistance tester in Fig. 2.
Specific implementation mode
In order to make the purpose of the utility model, technical solutions and advantages more clearly understood, below in conjunction with attached drawing and implementation
Example, the present invention will be further described in detail.It should be appreciated that specific embodiment described herein is only explaining this
Utility model is not used to limit the utility model.
The earth resistance tester of the utility model is auxiliary not using using the L phase lines of Devices to test, N zero curves, PE ground wires
Under conditions of index contour monitoring measure Devices to test ground state, as shown in Fig. 2, earth resistance tester include test circuit 1,
Test power supply circuit 2, test regulated power supply 3.
Test circuit 1 is used to test the potential difference between the N zero curves of Devices to test and PE ground wires.Test power supply circuit 2
Positive input terminal connects the L phase lines of Devices to test, and negative input end connects N zero curves.The positive input terminal for testing regulated power supply 3 connects L
Phase line, negative input end connect PE ground wires.
Test circuit 1 includes control circuit 4, reference pulse provides circuit 5, exchange constant current output circuit 6, two samples electricity
7, two, road filter circuit 8, display 9, operation button 10, telecommunication circuit 11.
Control circuit 4 is using with pulse output end P, the MCU of a pair of of differential input end ADC1, ADC2.
Two input terminals that reference pulse provides circuit 5 are separately connected the positive output end of test power supply circuit 2 and test steady
The positive output end of voltage source 3.Reference pulse provides circuit 5 under the Pulse Width Control of pulse output end P, provides the base of constant current output
Quasi- pulse.
The positive output end of the input terminal connecting test power supply circuit 2 of constant current output circuit 6 is exchanged, constant current output circuit is exchanged
6 under the control of the reference pulse, and the output for the positive output end for testing power supply circuit 2 is converted to setting for injection Devices to test
The exchange constant current output of the ground terminal at standby end 12.
Two sample circuits 7 sample N zero curves respectively and PE ground wires obtain corresponding sampled voltage, and are respectively fed to this to difference
Divide input terminal ADC1, ADC2, control circuit 4 is made thus to obtain the potential difference between N zero curves and PE ground wires.In order to improve potential difference
Exact value, two sampled voltages respectively by be re-fed into after the filtering of two filter circuits 8 this to differential input end ADC1,
ADC2。
Display 9 connects control circuit 4, thinks data information to be shown for display control circuit 4.
Operation button 10 connects control circuit 4, and assigning instruction to control circuit 4 by operation button 10 makes pulse output end
Export pulse.
Telecommunication circuit 11 connects control circuit 4, and assigning instruction to control circuit 4 by telecommunication circuit 11 makes pulse output end
P exports pulse.Telecommunication circuit 11 can be that RS232 telecommunication circuits can also be RS485 telecommunication circuits etc..
The earth resistance tester of the utility model, corresponding grounding monitor method include the following steps：
It is electric by testing voltage stabilizing that reference pulse provides the level that circuit 5 is connected on the positive output end of test regulated power supply 3
Stablize in a steady state value in source 3；
Reference pulse provides circuit 5 under the Pulse Width Control of pulse output end P, provides the reference pulse of constant current output；
Constant current output circuit 6 is exchanged under the control of the reference pulse, exchange constant current output injection the earth is formed and waits for
The ground terminal of the equipment end 12 of measurement equipment；
The electric current of the fixed frequency and size of injecting the earth flows back through PE ground wire-N zero curves all the way, all the way through the equipment end
Described in the ground terminal to the line resistance Rg- between the ground terminal of the distribution end 13 of Devices to test of the 12 ground terminal-equipment end 12
Ground terminal-N the zero curves of distribution end 13 flow back；
It is sampled through two sample circuits 7, differential input end ADC1, ADC2 of input control circuit 4 are obtained by Differential Input
Go out the potential difference between N zero curves and PE ground wires, to calculate " PE ground wire-N zero curves " and " ground terminal-of the equipment end 12
Distribution end 13 connects described in the ground terminal of the equipment end 12 to the line resistance Rg- between the ground terminal of the distribution end 13 of Devices to test
The resistance value of ground terminal-N zero curves ".
When PE ground wires disconnect, the grounding monitor method is changed into L phase lines and two collimation methods of N zero curves go to wait for described in measurement
The ground resistance of measurement equipment, reads grounding resistance in real time.For the realization method of the utility model of preferably illustrating, this practicality
Novel circuit is realized as shown in subsequent embodiment 1.
Embodiment 1
Referring to Fig. 3, the earth resistance tester of the utility model is using the L phase lines of Devices to test, N zero curves, PE ground wires,
Monitoring measures the ground state of Devices to test under conditions of not using auxiliary line.The earth resistance tester includes test electricity
Road, the test regulated power supply tested power supply circuit, voltage stabilizing electricity is provided the test circuit to test circuit power supply.
In the present embodiment, using test power supply circuit below, the test power supply circuit includes resistance R1, diode
D1, capacitance C1, resistance R3.One end of resistance R1 connects L phase lines, the anode of the other end connection diode D1 of resistance R1, two poles
Pipe D1 cathode connecting test circuit (following article introduction, the cathode of diode D1 simultaneously the resistance R4 of connecting test circuit and
Resistance R8).The cathode of one end connection diode D1 of capacitance C1, the other end of capacitance C1 connect N zero curves.Resistance R3 is connected in parallel on electricity
Hold on C1.
In the present embodiment, using test regulated power supply below, the test regulated power supply includes resistance R2, diode
D2, capacitance C2, zener diode Dz1.One end of resistance R2 connects L phase lines, the sun of the other end connection diode D2 of resistance R2
Pole, diode D2 cathode connecting test circuit (following article introduction, the photoelectricity two of the cathode connecting test circuit of diode D2
The collector of pole pipe OP1).The cathode of one end connection diode D2 of capacitance C2, the other end connect PE ground wires.Zener diode
The cathode of the cathode connection diode D2 of Dz1, the anode of zener diode Dz1 connect PE ground wires.Capacitance C1 and capacitance C2 may be used
To use electrolytic capacitor, as shown in Figure 3.
The test circuit includes control circuit MCU, capacitance-resistance RC1, resistance R6, capacitance-resistance RC2, resistance R7, resistance R4, photoelectricity
Diode OP1, resistance R8, junction field effect transistor J1, resistance R5.Wherein, the full name in English of junction field effect transistor is
Junction Field-Effect Transistor, referred to as JFET.
There is control circuit MCU a pair of of differential input end ADC1, ADC2, pulse output end P such as to use chip MDS
8HC908 just has a pair of of differential input end ADC1, ADC2, pulse output end P.
One end of capacitance-resistance RC1 connects differential input end ADC1, one end of the other end connection resistance R6 of capacitance-resistance RC1, resistance
The other end of R6 connects N zero curves.One end of capacitance-resistance RC2 connects differential input end ADC2, the other end connection resistance R7 of resistance RC2
One end, the other end of resistance R7 connects PE ground wires.
One end of resistance R4 connects the cathode of the diode D1 of the test power supply circuit, and the other end of resistance R4 connects light
The anode of electric diode OP1.The cathode of photodiode OP1 connects pulse output end P, and the collector of photodiode OP1 connects
Connect the cathode of the diode D2 of the test regulated power supply, one end of the emitter connection resistance R5 of photodiode OP1.Resistance
The emitter of the other end connection junction field effect transistor J1 of R5 simultaneously forms exchange constant current output end OUT, and junction field is brilliant
The emitter of the base stage connection photodiode OP1 of body pipe J1, the collector connection resistance R8's of junction field effect transistor J1
One end, the other end of resistance R8 connect the cathode of the diode D1 of the test power supply circuit.The exchange constant current output end OUT
Connection PE ground wires and the earth point to be measured for accessing Devices to test.
The test circuit may also include the accessories circuit such as display, operation button, telecommunication circuit.As display can be adopted
With LCD display, display connects control circuit MCU, and can be used for real-time display control circuit MCU needs every letter to be shown
Breath.For another example operation button, operation button connect control circuit MCU, and assigning instruction to control circuit MCU by operation button makes arteries and veins
Rush output end P output pulses.For another example telecommunication circuit, telecommunication circuit connects control circuit MCU, by telecommunication circuit to control circuit
MCU, which assigns instruction, makes pulse output end P export pulse, and RS232 communications, which may be used, in telecommunication circuit to use RS485 to communicate
Or other communication modes.
In monitoring, grounding monitor method includes the following steps the earth resistance tester：
The level of Vb is stablized by the test regulated power supply in a steady state value at the collector of photodiode OP1,
Junction field effect transistor J1 control pole constant voltages, junction field effect transistor J1 is given to collect after photodiode OP1 conductings
Constant current is exported at electrode when the level constant of Vb, the constant current is in exchange constant current output end OUT injection the earth；
The electric current of the fixed frequency and size of injecting the earth flows back through PE ground wire-N zero curves all the way, to be measured is connect through described all the way
The ground terminal-of distribution end described in the place-earth point to be measured to the line resistance Rg- between the ground terminal of the distribution end of Devices to test
N zero curves flow back；
It is sampled through resistance R6, resistance R7, after capacitance-resistance RC1, capacitance-resistance RC2 second order capacitance-resistance filters, the difference of input control circuit MCU
Point input terminal ADC1, ADC2, circuit potential difference is obtained by Differential Input, to calculate " PE ground wire-N zero curves " with it is " described
Distribution end described in the earth point-earth point to be measured to be measured to the line resistance Rg- between the ground terminal of the distribution end of Devices to test
The resistance value of ground terminal-N zero curves ".
When PE ground wires disconnect, the earth resistance tester is changed into two collimation methods of L phase lines and N zero curves from grounding monitor
The ground resistance for removing to measure the Devices to test, reads grounding resistance in real time.
The civilian electricity consumption ground impedance relay in China uses TNC-S, in electrical transformer room to each electricity consumption building three-phase five-wire mode, N
Zero curve is electrical equipment current loop, and PE is grounded for Electrical Safety.As shown in figure 4, earth resistance tester utilizes feeder ear
Neutral earthing is to measure auxiliary earth, measures line as auxiliary earth using N zero curves, power-supply system ground wire waits for for monitoring
Survey ground connection.It is grounded Injection Current to electricity consumption end system when earth resistance tester measures, when the three-phase five-wire mode of system is complete
When；For an Injection Current part by the reflux of PE, N, another part is flowed to by the earth arrives power supply ground terminal, flows back through N zero curves,
Measure the parallel value that resistance value is two circuits；When PE is lacked, due under normal circumstances, the PEN of feeder ear it is minimum, survey
Measure the power frequency electric resistance value that result is electricity consumption end.
Embodiment 2
In order to be better understood from the content of embodiment 1, more specifical realization method is used in example 2.
The selected value of primary circuit elements：R1=100 Ω, R2=470 Ω, R3=1M Ω, R4=470K Ω, R5=10K
Ω, R6=R7=100K Ω, R8=500 Ω, P1=MC3020, D1=D2=LM513, DZ1=36V voltage stabilizing, J1=P export arteries and veins
Rush frequency f=800hz.R1, D1, C1, R3 constitute the primary circuit elements of test power supply circuit；R2, D2, C2, DZ1 constitute test
The primary circuit elements of regulated power supply maintain constant level in Vb points, the reference pulse of constant current output, OP1 and J1 are provided for J1
Under the Pulse Width Control of MCU outputs, the exchange constant current output of OUT points is formed.
Testing procedure is as follows.
1. under operation button or RS232 instruction controls, the P output 800HZ pulses (through level conversion) of MCU control OP1
Break-make.
2. the level of Vb points gives J1 control pole constant voltages since the effect of Dz1 is constant after 36V, OP1 conductings, J1 is in Vb
Permanent timing output constant current, constant current inject the earth in OUT points.
3. the electric current of the fixed frequency and size of injecting the earth flows back through PE ground wires-N all the way, all the way through GND (equipment end)-
Rg-GND (distribution end)-N zero curves flow back.
4. being sampled through R6, R7, after RC1, RC2 second order capacitance-resistance filter, ADC1, ADC2 Differential Input of MCU is inputted, is obtained back
Road potential difference.To calculate the resistance of (PE ground wire-N zero curves) and (GND (equipment end)-Rg-GND (distribution end)-N zero curves)
Value.
5. when PE ground wires disconnect, measured value is the power frequency grounding resistance value that two step method measures.
In conclusion there are following technical essentials for the earth resistance tester of the utility model：
1) utilize L N PE ground wires connect, under conditions of not using other auxiliary lines, monitoring grounding state；
2) when PE ground wires break, grounding monitor is changed into two line measurement ground resistances, reads grounding resistance in real time.
The above is only the preferred embodiment of the utility model only, is not intended to limit the utility model, all at this
All any modification, equivalent and improvement etc., should be included in the utility model made by within the spirit and principle of utility model
Protection domain within.
Claims (8)
1. a kind of earth resistance tester, with the L phase lines of Devices to test, N zero curves, PE ground wires, in the condition for not using auxiliary line
Lower monitoring measures the ground state of earth point to be measured and the earth resistance tester of grounding resistance,
It is characterized in that, it includes：
Test circuit is used to test the potential difference between the N zero curves of Devices to test and PE ground wires；
Power supply is tested, positive input terminal connects the L phase lines of Devices to test, and negative input end connects N zero curves；Test voltage stabilizing electricity
Source, positive input terminal connect L phase lines, and negative input end connects PE ground wires；
Wherein, the test circuit includes：
Control circuit, with pulse output end, a pair of of differential input end；
Reference pulse provides circuit, two input terminal is separately connected the positive output end and control circuit of the test regulated power supply
Pulse output end；The reference pulse provides circuit under the Pulse Width Control of the pulse output end of control circuit, provides constant current
Reference pulse needed for output；
Constant current output circuit is exchanged, input terminal connects the positive output end of the test power supply, the exchange constant current output
The output of the positive output end of the test power supply is converted under the control of the reference pulse and injects to be measured connect by circuit
The exchange constant current output of the ground terminal in place；
Two sample circuits sample N zero curves respectively and PE ground wires obtain corresponding sampled voltage, and are respectively fed to controller
A pair of of differential input end makes the control circuit thus obtain the potential difference between N zero curves and PE ground wires.
2. earth resistance tester as described in claim 1, it is characterised in that：The test circuit further includes two filtered electricals
Road, two sampled voltages after the filtering of described two filter circuits respectively by being re-fed into a pair of of differential input end.
3. earth resistance tester as described in claim 1, it is characterised in that：The test power supply circuit includes：
Resistance R1, one end connect L phase lines；
Diode D1, anode connect the other end of resistance R1, and cathode connects the reference pulse and provides circuit and institute simultaneously
State exchange constant current output circuit；
Capacitance C1, one end connect the cathode of diode D1, and the other end connects N zero curves；And
Resistance R3 is connected in parallel on capacitance C1.
4. earth resistance tester as described in claim 1, it is characterised in that：The test regulated power supply includes：
Resistance R2, one end connect L phase lines；
Diode D2, anode connect the other end of resistance R2, and cathode connects the reference pulse and provides circuit；
Capacitance C2, one end connect the cathode of diode D2, and the other end connects PE ground wires；And
Zener diode Dz1, cathode connect the cathode of diode D2, and anode connects PE ground wires.
5. earth resistance tester as described in claim 1, it is characterised in that：The reference pulse provides circuit：
Resistance R4, one end connect the test power supply circuit；
Photodiode OP1, anode connect the other end of resistance R4, and cathode connects pulse output end, collector connection
The test regulated power supply, emitter connect the exchange constant current output circuit.
6. earth resistance tester as described in claim 1, it is characterised in that：The exchange constant current output circuit includes：
Resistance R8, one end connect the test power supply circuit；
Junction field effect transistor J1, collector connect the other end of resistance R8, and base stage connects the reference pulse and provides
Circuit；And
Resistance R5, one end connect the reference pulse and provide circuit, and the other end connects the hair of junction field effect transistor J1
Emitter-base bandgap grading simultaneously forms exchange constant current output end OUT, and the exchange constant current output end OUT connection PE ground wires simultaneously access the ground connection to be measured
Point.
7. earth resistance tester as described in claim 1, it is characterised in that：The earth resistance tester further includes connection
The display of control circuit.
8. earth resistance tester as described in claim 1, it is characterised in that：The earth resistance tester further includes connection
The operation button of control circuit, assigning instruction to the control circuit by the operation button makes pulse output end export arteries and veins
Punching；And/or the earth resistance tester further includes the telecommunication circuit for connecting control circuit, by the telecommunication circuit to institute
State control circuit assign instruction make pulse output end export pulse.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721929807.9U CN207964948U (en) | 2017-12-31 | 2017-12-31 | A kind of earth resistance tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721929807.9U CN207964948U (en) | 2017-12-31 | 2017-12-31 | A kind of earth resistance tester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207964948U true CN207964948U (en) | 2018-10-12 |
Family
ID=63730289
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721929807.9U Active CN207964948U (en) | 2017-12-31 | 2017-12-31 | A kind of earth resistance tester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207964948U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107907745A (en) * | 2017-12-31 | 2018-04-13 | 广东立信防雷科技有限公司 | A kind of earth resistance tester and its grounding monitor method |
-
2017
- 2017-12-31 CN CN201721929807.9U patent/CN207964948U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107907745A (en) * | 2017-12-31 | 2018-04-13 | 广东立信防雷科技有限公司 | A kind of earth resistance tester and its grounding monitor method |
| CN107907745B (en) * | 2017-12-31 | 2024-07-09 | 广东立信防雷科技有限公司 | Grounding monitoring method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105954594B (en) | A kind of reverse short distance measurement method and device of Novel connecting ground network ground resistance | |
| CN107907745A (en) | A kind of earth resistance tester and its grounding monitor method | |
| CN204832351U (en) | Small resistance and insulation resistance's integrated tester | |
| CN109444673A (en) | A kind of bunch of cables injection conducted susceptibility test macro and method | |
| CN203572883U (en) | Novel intelligent frequency-conversion large-current grounding impedance measuring instrument | |
| CN105510859A (en) | System and method for evaluating electronic transformer | |
| CN207964948U (en) | A kind of earth resistance tester | |
| CN205958652U (en) | Ground resistance detector | |
| CN204228947U (en) | A kind of single-phase real load electric energy table calibration equipment | |
| CN105896645A (en) | Charging function detection method, apparatus, and system for mobile terminal | |
| CN113125839A (en) | Non-isolated voltage sampling circuit, voltage sampling system and electric quantity metering device | |
| CN106443549B (en) | A kind of analog AC resistance device for calibration battery internal resistance test device | |
| CN211014495U (en) | AC-DC integrated charging pile test platform | |
| CN208224387U (en) | Integrated power transformation integrated test system | |
| CN208283463U (en) | A kind of Insulation Resistance Tester | |
| CN207502708U (en) | A kind of Three Phase Alternating-current Electrical Energy Meters verification system | |
| CN106374834A (en) | Voltage-ampere characteristic measurement circuit and method of solar cell | |
| CN207516439U (en) | Alternating current acquisition module and detection device | |
| CN205787074U (en) | A kind of grounding device tester anti-Hz noise capability evaluation device | |
| CN201527459U (en) | Tracker of grounding point of power overhead line | |
| CN104502673B (en) | The current true virtual value transmitter of AC/DC universal | |
| CN103675470A (en) | N*M dimension resistor network measuring device | |
| CN206450761U (en) | Exempt from the device that dismounting ground wire tests steel tower grounding resistance | |
| CN207742325U (en) | The calibration of direct current energy meter and test fixture | |
| Goulart et al. | Automated system for measuring electrical three-phase power components |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |