EARTH RESISTANCE TESTER
Wuhan Kangda Electrical CO., LTD
Address: 30 ShuCheng Road XiongChu Avenue HongShan
http://www.chinakddq.com WUHAN KANGDA ELECTRICAL CO., LTD
Tel: +86-27-8738 1005 8739 9915 8738 3472
Fax: +86-27- 8738 6393
●To ensure the accuracy and reliability of the instrument, protect
Dear Users: For your safety and the
it from damaging environmental conditions such as excessive
proper use of the instrument, please read all of
humidity, direct sunlight and rain and avoid physical damage such
as knocks or falls. the instructions carefully before operation.
7. Accessories Safety requirements meet IEC61010-1:2001
Test leads (red, yellow, green, black, 1.5m each) Performance standard Q/KD 05-2004
Two metal probes
Test wires (20m & 40m)
Instruction Manual ● Earth resistance measurement of various earth installations.
Certificate of Quality ● Measurement of low resistance conductor
Carry-case ● Four-pole measuring technology, suitable for ground
8×1.5V ( LR6 ) batteries resistivity measurement.
● Anti-disturbance to earth voltage (up to 5V).
● 3 1/2 LCD digital display.
● 20V AC voltage meter.
● Low power consumption and powered by 8×1.5V batteries.
● Low battery indication “ ”.
● “OPEN CIRCUIT” indication on LCD.
● Portable and easy-to-operate.
-8 - -1 -
2. Specifications 4.5 Conductor Resistance Measurement
2.1 Earth Resistance Test
● Measuring Ranges：
0～19.99Ω 20～199.9Ω 200~1999Ω
● Measuring Current
Base Error： (5% RDG + 2d)
Error caused by earth voltage：2% ACV 50Hz ≤5V
Error caused by auxiliary earth resistance：≤2%
Where the potential terminal RP≤50k； Fig.4 Conductor Resistance Measurement
or the current terminal Rc≤1k (20 position) Connect C1 to P1 and C2 to P2. Then connect each end of the
Rc≤10k (200 or 2000 position) conductor under test to C2, P2 and C1, P1 respectively. Select a
2.2 Earth Voltage Measurement proper range, then press the TEST button and read the resistance
value R from the Display.
Measuring Ranges ＆Accuracy：
(0～19.99)V; (5% of RDG+2d)
5.Turn Off Power Supply
Input Impedance： ＞300kΩ Function switch at AC.V position, Press TEST ON-OFF button
2.3 Others can turn on/off the power supply. The LCD will be turned off when
Insulation Resistance: ≥20M(500V) power supply is turned off.
Withstand Voltage: AC 1.5kV 50Hz 1min
Operating Temperature &. Humidity: -10℃~ +50oC≤85%RH
●If the instrument is to be stored for long periods, the batteries
Storage Temperature &. Humidity: -15℃~ +55oC ≤90%RH should be removed to avoid potential damage to the instrument
Power Supply: 8×1.5V ( R6, LR6 ) batteries due to leaking batteries.
Power Consumption: ≤150mA ●Ensure the instrument is kept clean. Cleaning is recommended
using a dry cloth when necessary.
Weight: Approx. 0.8kg
4.4 Earth Resistivity Measurement 3. Instrument Layout
Fig.3 Earth Resistivity Measurement
Insert four metal probes into the ground every “a” centimeter
along a line within the measured area. The burying depth of the
metal probe should be about 1/20 of the distance “a”. According
to Fig.3, the probes are connected to C1, P1, P2 and C2 by four
wires respectively. Press the TEST button, read the resistance
value R from the LCD after the Current Output Indicator is
turned on. The measured earth resistivity is calculated by equation
Where: R: measured resistance value ()
a: distance between each probe (cm) 1. Battery case(back) 4. Potential terminal 7. Open circuit alarm
: measured earth resistivity (·cm) 2.Fuction switch 5. Current terminal 8. Current output indicator
3. LCD 6. Low battery sign 9. ON-OFF / TEST button
4. Operating Instructions
4.1 Batteries check and replace
If the sign “ ” is displayed on LCD when the instrument is -4-
powered, it indicates the batteries should be replaced.
4.2 Earth Voltage Measurement
Fig.2 Earth Resistance Measurement
● to to
Connect probe E′ C2 and P2 terminals, P′ P1 terminal and
C′ C1 terminal by test wires.
● Select a desired measuring range.
● When the Current Output Indicator Lamp (LED) is turned on,
Fig.1 Earth Voltage Measurement
it shows the output test current is turned on, The measured earth
As shown in Fig.1, the probes E′ P′ connected to the C2 & P2 resistance value will be displayed on the LCD.
terminals. Set Function switch at AC.V position. Press the ● Pressing TEST ON-OFF button, the test current can be
ON-OFF button to turn on the power, Then read the AC.V value turned on/off .
from the LCD.
4.3 Earth Resistance Measurement
a) If the loop C2E′ C1 is open or the resistance value of
● Use the tested earth probe E′as the starting point, locate the
positions for potential probe P′ current probe C′
and along a auxiliary resistance RC exceeds the upper limit, OPEN
straight line as shown in Fig.2 with 20 meters space between E′P′ CIRCUIT will be displayed on the LCD. Please check the loop
and P′ . or take measures to decrease the value of RC.
b) In order to get accurate measurements, the position of potential
probe P′should be placed as near to the middle of E′and C′