3143 EARTH HiTESTER INSTRUCTION MANUAL
Contents Introduction Inspection Safety Notes Notes on Use i i ii vi Chapter 1 Outline 1 1.1 Product Outline 1.2 Features 1.3 Names and Functions of Parts Chapter 2 Specifications Chapter 3 Measurement Procedure 1 2 4 7 11 3.1 Measurement Preliminaries 3.2 Measuring method 12 13 Chapter 4 Technical Information 19 4.1 About Ground Resistance 4.2 Principle of Conventional Measurement of Ground Resistance (Fall-of-Potential Method) 4.3 Principle of Measurement on Which This Instrument is Based 4.
.5 Sample Measurement (Measurement of Ground Resistance for Overhead Telecommunications Equipment and Various Types of Protectors) 26 Chapter 5 Precautions concerning Measurement 29 Chapter 6 Maintenance and Service 31 6.1 6.2 6.3 6.
i ――――――――――――――――――――――――――― Introduction Thank you for purchasing the HIOKI 3143 EARTH HiTESTER. To obtain maximum performance from the instrument, please read this manual first, and keep it handy for future reference. Inspection When you receive the instrument, inspect it carefully to ensure that no damage occurred during shipping. In particular, check the accessories, panel knob, and connectors.
ii ――――――――――――――――――――――――――― Safety Notes WARNING This instrument is designed to comply with IEC 61010 Safety Standards, and has been thoroughly tested for safety prior to shipment. However, mishandling during use could result in injury or death, as well as damage to the instrument. Be certain that you understand the instructions and precautions in the manual before use. We disclaim any responsibility for accidents or injuries not resulting directly from instrument defects.
iii ――――――――――――――――――――――――――― The following symbols in this manual indicate the relative importance of cautions and warnings. DANGER Indicates that incorrect operation presents an extreme hazard that could result in serious injury or death to the user. WARNING Indicates that incorrect operation presents a significant hazard that could result in serious injury or death to the user. CAUTION Indicates that incorrect operation presents a possibility of injury to the user or damage to the instrument.
iv ――――――――――――――――――――――――――― Measurement categories (Overvoltage categories) This instrument complies with CAT I safety requirements. To ensure safe operation of measurement instruments, IEC 61010 establishes safety standards for various electrical environments, categorized as CAT I to CAT IV, and called measurement categories. These are defined as follows. CAT I: Secondary electrical circuits that are connected to a wall outlet through a transformer or similar device.
v ――――――――――――――――――――――――――― Higher-numbered categories correspond to electrical environments with greater momentary energy. So a measurement device designed for CAT III environments can endure greater momentary energy than a device designed for CAT II. Using a measurement instrument in an environment designated with a highernumbered category than that for which the instrument is rated could result in a severe accident, and must be carefully avoided.
vi ――――――――――――――――――――――――――― Notes on Use Follow these precautions to ensure safe operation and to obtain the full benefits of the various functions. Preliminary Checks Before using the instrument the first time, verify that it operates normally to ensure that the no damage occurred during storage or shipping. If you find any damage, contact your dealer or Hioki representative.
vii ――――――――――――――――――――――――――― DANGER The ground and return measurement terminals of this instrument are designed to measure ground resistance. Accidental connection of the terminals to a commercial power source or potential-bearing object may result in electric shock. Exercise extreme care. WARNING Do not allow the instrument to get wet, and do not take measurements with wet hands. This may cause an electric shock.
viii ――――――――――――――――――――――――――― WARNING To avoid electric shock, turn the power switch off and disconnect the measurement cables before replacing the batteries. To avoid the possibility of explosion, do not short circuit, disassemble or incinerate batteries. Handle and dispose of batteries in accordance with local regulations. CAUTION Do not store or use the instrument where it could be exposed to direct sunlight, high temperature or humidity, or condensation.
ix ――――――――――――――――――――――――――― CAUTION To avoid corrosion from battery leakage, remove the batteries from the instrument if it is to be stored for a long time. To avoid damage to the instrument, protect it from physical shock when transporting and handling. Be especially careful to avoid physical shock from dropping.
x ――――――――――――――――――――――――――― ―――――――――――――――――――――――― Notes on Use
1 ――――――――――――――――――――――――――― Chapter 1 Outline 1.1 Product Outline In contrast to conventional 3-pole type ground resistance meters, this instrument allows easy measurement of ground resistances, with no need to drive auxiliary earthing electrodes into the ground - whether soil or asphalt. This is particularly useful when ground resistances need to be measured in urban environments, in which driving auxiliary earthing electrodes into the ground is not easy or practical.
2 ――――――――――――――――――――――――――― Return Cable Measurement Cable Grounded body being measured (Bar-type earthing electrode) Ground Figure 1 1.2 Features (1) No need to drive auxiliary earthing electrodes into the ground Allows easy measurement of ground resistances, simply by connecting the earthing electrode to the measurement terminals (Ground side) of the instrument and the return line (red line) to the other terminal (Return side) and placing the return line on the ground.
3 ――――――――――――――――――――――――――― (3) Reduces the effects of ground voltage The instrument uses a synchronous detection system, with the return line placed directly on the ground in an electrically insulated state. This reduces the adverse effects of higher harmonic ground voltages of commercial frequency to ensure stable measurement. (4) Semi-dust-proof construction Measurement switches, indicators and other moving parts are designed to withstand use in tough environments.
4 ――――――――――――――――――――――――――― 1.3 Names and Functions of Parts 7. 4. 1. 3. 8. 9. 6. 2. 5. 10. 11.
5 ――――――――――――――――――――――――――― 1. Power switch (POWER) Instrument power switch 2. Measuring knob (MEASURE) Knob for measuring ground resistances. Turn the knob until the instrument indicates a minimum resistance value. 3. Earth: Earthing electrode terminal Terminal to which the earthing electrode is connected, via the lead line (black). 4. Return: Return terminal Terminal to which the return line (red) is connected. Position the return cable directly on the ground. 5. LCD display 6.
6 ――――――――――――――――――――――――――― 9. Battery check Indicates that the batteries have been exhausted. Replace the batteries. 10. Battery cover 11.
7 ――――――――――――――――――――――――――― Chapter 2 Specifications Measurement method Voltage ratio method (measures the voltage under the series resonance of a loop impedance [Note].) When measured with the lead line connected to the earthing electrode being measured and the return line placed directly on the ground, the resistance value sought is the one that appears as the minimum value in the display as the measuring knob is turned.
8 ――――――――――――――――――――――――――― Averaging processing Sampled values are subjected to averaging, and the resulting value is indicated as a measured value. Frequency range 100 kHz - 1.5 MHz Adjustable using the measuring knob on the front panel Frequency variation resolution 240 Hz Output voltage between terminals 0.9 Vp AC, typical Output resistance between terminals 200 Ω 1% The short-circuit current between terminals is 3.
9 ――――――――――――――――――――――――――― Storage temperature and humidity range -10 to 50 (14 to 122 ), 80% RH or less (with no condensation) Location of use Altitude up to 2000 m (6562 feet) Power supply Four LR6 alkaline batteries Rated supply voltage: 1.5 V x 4 Maximum rated power 1.5 VA max Battery Life Approx. 8 hours (continuous, 23 ) External dimensions Approx. 155 W x 98 H x 49 D mm (Approx. 6.10"W x 3.86"H x 1.93"D) (excluding protrusion) Mass Approx. 380 g (Approx.
10 ――――――――――――――――――――――――――― Power Saving mode The instrument enters Power Saving mode if the measuring knob is left untouched for about 3 minutes. Output of the measurement signaling source is halted. The LCD displays "HOLD." Turn the measuring knob to wake the instrument from Power Saving mode. Indicator Indicates an approximate position of the resonance point of the loop impedance on a bar graph.
11 ――――――――――――――――――――――――――― Chapter 3 Measurement Procedure DANGER The ground and return measurement terminals of this instrument are designed to measure ground resistance. Accidental connection of the terminals to a commercial power source or potential-bearing object may result in electric shock. Exercise extreme care. WARNING Do not allow the instrument to get wet, and do not take measurements with wet hands. This may cause an electric shock.
12 ――――――――――――――――――――――――――― WARNING Do not mix old and new batteries, or different types of batteries. Also, be careful to observe battery polarity during installation. Otherwise, poor performance or damage from battery leakage could result. CAUTION Use only the specified battery type (AA alkaline). Manganese batteries, for example, will provide insufficient service life. To avoid corrosion from battery leakage, remove the batteries from the instrument if it is to be stored for a long time. 3.
13 ――――――――――――――――――――――――――― 3.2 Measuring method (1) Connecting the cables Connect the measurement cables 9265 supplied with the instrument, as shown in Figure 3. (Couple the lead line [black] to the ground terminal, and the return line [red] to the Return terminal.) Connect the other end of the lead line to the buried earthing electrode and lay the return line on the ground (on paved concrete or asphalt). Lead line (Black) 1 m Return line (Red) 20 m Figure 3.
14 ――――――――――――――――――――――――――― NOTE Use only the measurement cables supplied with the instrument. Use of any other cable will result in inaccurate measurements. Lay the return line directly on the ground in a straight line, confirming that the cable remains in contact with the ground. Correct measurements are not possible if the cable is tangled or forms loops. Particularly with turf or rock beds, try to place the return line in close contact with the ground to the maximum extent possible.
15 ――――――――――――――――――――――――――― (2) Measurement of ground resistance value Turn the measuring knob (MEASURE) to find the lowest indicated value. The lowest value represents the resistance value of the earthing electrode being sought. Turn the measuring knob as follows: 1) The measurement indicator bar shows the direction in which the knob should be turned. If the indicator bar appears as shown in Figure 4(a), turn the knob counterclockwise to bring the indicator bar to the " " Figure 4(a). position.
16 ――――――――――――――――――――――――――― NOTE The measurement indicator bar displayed may not stabilize, depending on the resistance value of the grounded body being measured or the environment in which the return line is laid. Particularly for measurements of large ground resistances, no minimum value may be shown, even when the indicator bar is located in the center of the display. If so, turn the knob to minimize the indication value. If the measured resistance value is 1000 Ω or more, the LCD will display "OF.
17 ――――――――――――――――――――――――――― (3) Hold status The instrument will enter Hold status if the measuring knob (MEASURE) is left untouched for about 3 minutes ("HOLD" is displayed: see Figure 5), with the value measured immediately before the Hold state retained on the display. In addition, the signal from the measurement terminals (between the Ground Return terminals) is interrupted. Turning the knob in this status cancels Hold and resumes measurement. HOLD displayed Figure 5.
18 ――――――――――――――――――――――――――― ―――――――――――――――――――――――― Chapter 3 Measurement Procedure
19 ――――――――――――――――――――――――――― Chapter 4 Technical Information This chapter explains the definition of generic ground resistance, types of grounding implementations, principles of measurement of typical ground resistances, and describes grounding methods/implementations and resistance measurements for overhead telecommunications equipment and protectors, as exemplified in typical measurement situations. 4.
20 ――――――――――――――――――――――――――― (2) Leakage current and ground voltage In ordinary ground resistance measurements, external influences include leakage current from connected equipment and ground voltage created by ground current. Since the return line of the instrument is laid on the ground in an electrically insulated state, the instrument is relatively resistant to the adverse effects of leakage currents and ground voltages generated by higher harmonics (up to 1 kHz or so) generated by commercial power.
21 ――――――――――――――――――――――――――― 4.2 Principle of Conventional Measurement of Ground Resistance (Fall-of-Potential Method) Most ground resistance meters perform measurements based on the fall-of-potential method. These types of meters are widely used in the measurement of the low resistance to the high resistance.
22 ――――――――――――――――――――――――――― Driving in auxiliary electrodes is difficult at sites where the ground is paved with concrete or asphalt, resulting in reduced work efficiency. lm (a) xm E Rx P (b) Measurement value C Earth surface Horizontal section Rc Resistance range Resistance range of electrode E of electrode C xm lm 4.
23 ――――――――――――――――――――――――――― Return line Lead line Ground Grounded body being measured 3143 Rout Vc Vm Lg R Rg Cg Figure 8. Diagram of Measurement Principle R ≅Rout+Rg R'=Rout+Rg+ 1+(wCgR)2 As shown above, R' represents the sum of ground resistance Rg and Rout. If the voltage Vm between the measurement terminals is measured, ground resistance Rg may be calculated by the voltage ratio method.
24 ――――――――――――――――――――――――――― In passing, the resonance frequency will be high - around 1 MHz - although it will vary somewhat with varying geological features, water content, and degree of soil compaction. Since this frequency band corresponds to the duration of the wave front of a lightning surge, measurements of ground resistances using this instrument may be regarded as similar to the evaluation of surge impedances. 4.
25 ――――――――――――――――――――――――――― Measured Value of 3143 (ohm) 500 100 50 10 10 50 100 500 Measured Value of 3-Electrode Method (ohm) Figure 9. Correlation between Values Measured by 3-Electrode Method and with the 3143 Rdg. Error of 3143 (%) 40 30 20 10 0 -10 -20 -30 -40 10 50 100 500 Measured Value of 3-Electrode Method (ohm) Figure 10. Rdg.
26 ――――――――――――――――――――――――――― 4.5 Sample Measurement (Measurement of Ground Resistance for Overhead Telecommunications Equipment and Various Types of Protectors) It is increasingly common to find some switching and transmission equipment functions formerly located within telecommunications center buildings on or near the premises of residences. This configuration makes it possible to provide diverse information services through various types of networks.
27 ――――――――――――――――――――――――――― (1) It is necessary to confirm that the ground resistance value obtained following grounding implementation is lower than the value specified in a standard for safety of each country. (2) Many of the work sites are in residential and office building areas, which means that most of the ground surface is asphalted, making it time and labor-consuming to drive in auxiliary earthing electrodes using the conventional 3pole method.
28 ――――――――――――――――――――――――――― Subscriber protector Communications line protector Overhead telecommunications equipment (closure, etc.) Grounding electrode Paved ground Grounding electrode Grounding electrode Figure 12. Environment Surrounding Overhead Telecommunications Equipment and Protector 3143 Grounding electrode Figure 13.
29 ――――――――――――――――――――――――――― Chapter 5 Precautions concerning Measurement This instrument measures ground resistances based on a new measurement principle. For this reason, depending on the grounded body, the values obtained with it may vary from those measured by the traditional 3-pole method. Carefully read the following precautionary notes before using this instrument. (1) The 3143 is suitable for measuring the ground resistances of independent bar-type electrodes.
30 ――――――――――――――――――――――――――― For resistance measurements with safety implications, especially grounding connectors for power facilities, double-check resistance values using the 3-pole method. (2) Use only the measurement cables (9265 MEASUREMENT CABLE) supplied with the instrument. Use of other cables may result in measurement errors. (3) Lay the return line directly on the ground, ensuring contact with the ground.
31 ――――――――――――――――――――――――――― Chapter 6 Maintenance and Service 6.1 9338 CARRYING CASE The 9338 CARRYING CASE is designed exclusively for this instrument and is capable of accommodating 9265 MEASUREMENT CABLE and four AA batteries in addition to the instrument itself. With the upper cover rotated as shown in Figure 14, measurements can be made without removing the instrument from the case.
32 ――――――――――――――――――――――――――― 6.2 Replacing the Batteries WARNING To avoid electric shock, turn the power switch off and disconnect the measurement cables before replacing the batteries. After replacing the batteries, replace the cover and screws before using the instrument. To avoid the possibility of explosion, do not short circuit, disassemble or incinerate batteries. Handle and dispose of batteries in accordance with local regulations. NOTE Use only the specified battery type (AA alkaline).
33 ――――――――――――――――――――――――――― B A Screw Figure 15. 1. For safety, disconnect the measurement cables from the instrument. 2. Remove the fastening screw. 3. Remove the cover of the battery compartment in direction A, as shown in the illustration. 4. Replace all four batteries with fresh ones. 5. Reattach the cover of the battery compartment in direction B, as shown in the illustration. 6. Fasten the battery compartment cover to the instrument with the fastening screw.
34 ――――――――――――――――――――――――――― 6.3 Cleaning the Product To clean the instrument, wipe it gently with a soft cloth moistened with water or mild detergent. Never use solvents such as benzene, alcohol, acetone, ether, ketones, thinners or gasoline, as they can deform and discolor the case. 6.4 Service If the instrument seems to be malfunctioning, confirm that the batteries are not discharged, and that the measurement cable is not open circuited before contacting your dealer or Hioki representative.
HIOKI 3143 EARTH HiTESTER Instruction Manual Publication date: September 2006 Revised edition 4 Edited and published by HIOKI E.E. CORPORATION Technical Sales Support Section All inquiries to International Sales and Marketing Department 81 Koizumi, Ueda, Nagano, 386-1192, Japan FAX: 0268-28-0568 TEL: 0268-28-0562 E-mail: os-com@hioki.co.jp URL http://www.hioki.co.
HEAD OFFICE 81 Koizumi, Ueda, Nagano 386-1192, Japan TEL +81-268-28-0562 / FAX +81-268-28-0568 E-mail: os-com@hioki.co.jp URL: http://www.hioki.co.
