Instruction Manual for DigitalGrounding Resistance Meter

1

Instruction Manual for DigitalGrounding Resistance Meter

Table of Contents

I. Overview…………………………....2II. Open-case Inspection……………....3III. Safety Precautions……………..….4IV. Work Principle…………………....7V. Appearance Description…………...9VI. Technical Characteristics…………10VII. Resistance Measurement Method..12VIII.Battery Installation………………20IX.Troubleshooting…………………...22

2

WarningThe warnings and safety requirementsstated in this manual must be strictlyobserved to ensure safety. Please read theoperating instructions carefully beforeusing this meter.

I. OverviewGrounding Resistance Meter, as aprofessional instrument for measurementof grounding resistance of electricalequipment, is made by improving thecircuit, structure and technology oftraditional ground resistance meter. Witha beautiful and practical fashion style,this meter will provide more completefunction, higher accuracy and moreconvenient operation. Thanks to the

3

dust-and-moisture proof structure, thismeter is better suited to field operation. Itis designed to measure the groundingresistance of grounding systems of avariety of power systems, electricalequipment and lightning protectionequipment, and also to measure ACvoltage.

II. Open-case Inspection1. Grounding resistance meter

1 set2. Canvas bag

1 Pcs3. Ground drill rod

2 Pcs4. Auxiliary testing wire

1 set(including: a piece of 15-meter red

4

wire, 10-meter yellow wire, and5-meter green wire)

5. Simple testing wire1 set(including: a piece of 1.6-meter red

wire and 1.6-meter green wire)6. 5# alkaline battery (LR 6 AA) (1.5V)

x 8 8 Pcs7. Instruction manual

1 copy8. Strap

1 piece

III. Safety Precautions

1. Please read this instruction manualcarefully before using this groundingresistance meter

2. Do not use the grounding resistance

5

meter and measuring wire withdamaged surface.

3. Do not touch the conductor with avoltage of higher than DC 60V orAC36V RMS in order to prevent electricshock, since the said voltage has reachedthe standard of electric shock.4. Before the measurement of resistance,the tester must be completely isolatedwith power circuit in order to ensureaccurate readings and personal safety.

5. The meter shall not be stored at hightemperature; direct sunlight shall beavoided so as not to affect the servicelife of LCD.

6. When the symbol " " which

indicates "low battery" appears, thebattery shall be replaced. Before

6

long-term storage, the batteries shallbe taken out to prevent the damage tometer caused by battery leakage.

7. Special care should be exercisedduring the measurement for bare wires.8. The battery will be disconnected whenan external adapter is used. In this case,the battery cannot be recharged. Note:please select the power supply mode( ) .

9. Grounding resistance testingrequirements:a. The AC grounding resistance shall notbe greater than 4Ω;b. The safety grounding resistance shallnot be greater than 4Ω;c. The DC grounding resistance shall bedetermined according to specificrequirements of computer system;

7

d. Lightning protection groundingresistance shall not be greater than 10Ω;e. For the joint grounding of shieldingsystem, the grounding resistance shallnot be greater than 1Ω;

Warning! ResistanceHigh

Voltage!Dangerous!

AC

Earth Batteryunder-voltage

Doubleinsulation CE complied

IV.Work Principle

The measuring principle of groundingresistance is based on the law of

8

resistance. Insert 4 electrodes (E1, P1, P2,E2) to a certain depth under the ground,and the distance between electrodes shallbe around 20 meters. See the figurebelow:

AC signals act on electrodes E1 and E2,and the current that flows through theearth shall be measured by ammeterthrough electrodes P1 and P2. If thecurrent value is a constant, the measuredvoltage will be proportional to earthresistance. The displayed value dependson swamping resistance; hence, theappropriate range shall be determined

9

according to measured resistance valuesin order to get the best readings. ACsignal is generated by the built-inconverter.

V. Appearance Description

1, 2, 3 and 4: Range selector switch (2 0Ω/200Ω/2000Ω /EARTH VOLTAGE).5: Digital holding switch (HOLD)6: Power Switch: self-locking powerswitch (POWER)7: Testing indicator: this lamp goes onduring the testing if the connection iscorrect.

10

8: Test button.9: LCD: display measurement data andunit symbols.10: Instrument model11: P port: potential pole.12: C port: current pole.13: E port: grounding pole.14: ACV port: voltage pole.15: Power adapter jack ( ).

VI. Technical Characteristics

1. General features(1) Display: 84.8 × 59.8mm

window-type LCD display;Maximum displayed value "1999".

(2) Over-range indication: the firstdigit is "1" when the upper limit isexceeded.

11

(3) Power supply: 5# alkaline batteryLR6 (1.5V) x 8 (can be connected tooptional adapter); under-voltageindication function is provided.

(4)Power consumption:powerconsumption during no-load testing is≤800mw.

(5) Operating environment: 0℃ - 4 0℃ .Relative humidity: 30% - 85%RH.

(6) Overall dimensions: 175（L）×110(W)×70（D）mm

(7)Weight: about 680g (includingbatteries).

2. Technical dataGrounding resistance

12

Measuringrange

Basicaccuracy Resolution

20Ω ±（2%+0.1Ω） 0.01Ω

200Ω±（2%+3d）

0.1Ω

2000Ω 1Ω

Grounding voltage (50Hz - 200Hz)Measuring

range

Basic accuracy Resolution Input

impedance

Overload

protection

200 V ±( 2.0 % + 6 d ) 0.1 V 1 MΩ 200V rms

VII. Resistance Measurement Method

7-1. Battery voltage inspectionAfter the startup, if the battery

symbol is not indicated on the display,it means that the current power is

13

sufficient. When the display flashes orshows this symbol, please replace thebattery in accordance with instructionsin Chapter VIII.

7-2. Testing wire connectionPlease make sure the plug of testing

lead has been completely inserted intothe test side. The loose connection maylead to errors in the measurementresults.

7-3 Test methodDanger: an AC voltage of up to 50V

may occur between E-C or E-Pterminals during the measurement ofgrounding resistance. Do not touch testlead so as to avoid electric shock.

7-3-1Conventional resistancemeasurement method

1) Test lead connection

14

As shown below, insert theauxiliary grounding rods P and C into theground vertically at the point 5-10 metersfrom the grounded object, connect thegreen wire to instrument terminal E, theyellow one to terminal P, and the red oneto terminal C.

Note: Please insert the auxiliarygrounding rod into the ground with highwater content. If the rod is to be insertedinto dry ground, silica-containing groundor the ground with gravels, the groundshall be wetted with water in order toensure that the grounding rod be insertedinto wet ground. In case of cementground, please apply water to thehorizontally placed grounding rod, andcover it with wet towel before the

15

measurement.

2) Grounding voltage measurementPlease set the range selector switch to

Earth Voltage position. If the voltagevalue is displayed on the screen, it meansthere is grounding voltage in the system.Please check if the voltage value is lowerthan 10V. If the value is above 10V, anerror of measured grounding resistancevalue may occur. In this case, please turnoff the power supply of tested groundingdevice, and carry out the measurementafter the grounding voltage drops.3) Grounding resistance measurement

16

Start from the 2000Ω level, and pressthe "TEST" key. Backlight goes on toindicate that a test is in progress. If thedisplayed value is too small, you canchange the level to 200Ω , 20Ω .... Thedisplayed value under this circumstanceis the measured value of groundingresistance.

Note: The symbol " " means the

grounding impedance of auxiliarygrounding rod C is too high. In this case,please check if the connection is loose, orincrease the humidity of ground aroundthe auxiliary grounding rod to reduceground impedance.

Note: Ensure that the wires are notentwined. If the testing wires are

17

entwined with each other, the mutualinduction may occur during the testing in"false connection" condition and willinfluence the readings. If the auxiliarygrounding impedance is too strong, anerror of display value may occur. Ensurethat the auxiliary grounding rods P and Care inserted into wet ground, and all theconnection parts are in full contact.7-3-2. Simple grounding resistancemeasurement method

This is a simple method for theplaces where insertion of auxiliarygrounding rod is not available. For thismethod, a grounding electrode like metalwater pipe, commercial electric powersystem common grounding terminal orstructure grounding terminal, etc. withextremely weak grounding impedance is

18

used instead of auxiliary grounding rodsC and P. Please use simple test leads.

1) Test lead connectionPlease connect the leads according to

the figure below.Note: If the simple test leads suppliedtogether with this instrument are not used,please make a short circuit for terminalsC and P.

2) Grounding voltage measurementPlease set the range selector switch to

19

Earth Voltage position. If the voltagevalue is displayed on the screen, it meansthere is grounding voltage in the system.Please check if the voltage value is lowerthan 10V. If the value is above 10V, anerror of measured grounding resistancevalue may occur. In this case, please turnoff the power supply of tested groundingdevice, and carry out the measurementafter the grounding voltage drops.3) Grounding resistance measurementStart from the 2000Ω level. Please

press the "TEST" button. The backlightgoes on to indicate a test is in progress. Ifthe displayed value is too small, pleaseswitch to the 200Ω /20Ω level. Thevalue displayed in this case is thegrounding resistance value. Please turnoff the power switch after the test is

20

completed in order to save power.

Note: ● The measured current is about2mA. The circuit breaker will not beactuated even if a leakage circuit breakeris connected.

● The real grounding resistancevalue RX is subject to thefollowing formula:

RX = RE - rere: grounding resistance of

common ground terminal ofcommercial power systemetc.

Re: instrument groundingresistance reading

VIII. Battery Installation

21

When the battery power is low, a " "symbol will appear on the screen, whichmeans the battery needs to be replaced.Turn off the instrument and take out thebatteries.Unscrew the screws at battery door witha screwdriver.Open the battery door.Load a new battery (pay attention topolarity).Close the battery cover and tighten thescrews.

Step I Step II

22

IX.Troubleshooting

If your meter can't operate properly, thefollowing methods can help you quicklyresolve general problems. If the faults arestill not removed, please contact theservice center or distributor.

Symptom Check position andmethod

No display● Power supply is not

connected;● Replace the battery.

symbol

occurs● Replace the battery.

Big displayerror ● Replace the battery.

23

This manual is subject to change withoutnotice.The contents of this manual areconsidered correct. If you find someerrors and omissions therein, pleasecontact the manufacturer.We are not responsible for any accidentand hazard due to user's faulty operation.The functions described in this manualcannot be taken as the reason for usingthis product for special purposes.

601E-4105-000A