What instrument is better to measure the ground resistance?

The grounding resistance measuring instrument abandons the traditional manual hand-cranked power generation working mode, adopts advanced medium and large-scale integrated circuits, and uses DC AC conversion technology to combine the three-terminal button and four-end button measurement methods into a new type of grounding resistance measuring instrument. The working principle is that the DC converter in the machine converts DC into AC low-frequency constant current, through the auxiliary grounding electrode C and the DUT E to form a loop, the AC voltage drop is generated on the DUT, which is sent to the AC amplifier for amplification through the auxiliary grounding electrode P, and then sent to the meter head display through the detection. With the help of the magnification switch, three different limits can be obtained:

The structure is made of high-strength aluminum alloy as the chassis, and the circuit adopts the phase-locked loop synchronous tracking detection mode and the switching capacitor filter to prevent power frequency and radio frequency interference, so that the instrument has a good anti-interference ability.

DC AC conversion technology is used to convert DC into AC with a low-frequency constant current for easy measurement. The auxiliary ground resistance is allowed to vary between 0 2k (rc) and 0 40k (rp) without affecting the measurement results. The ground resistance gauge does not need to manually adjust the balance, and the 3 (1 2) position LCD shows that in addition to the ground resistance, it can also measure the low resistance conductor resistance, soil resistivity, and AC ground voltage.

If the test loop is not through, the meter header shows "1", which means overflow, which is in line with the conventional measurement habits. When storing and keeping this watch, you should pay attention to the ambient temperature and humidity, and it should be placed in a dry and ventilated place to avoid moisture, and should prevent acid, alkali and corrosive gases. When measuring the protective ground resistance, be sure to disconnect the electrical equipment from the power supply connection point.

When measuring the grounding resistance less than 1, they should be connected to the grounding body with special wires, C2 on the outside and P2 on the inside. When measuring the grounding resistance of a large grounding network, it cannot be measured according to the general wiring method, and the buried point can be selected with reference to the provisions of the ammeter and voltmeter measurement method. When measuring ground resistance, it is best to repeatedly measure 3 or 4 times in different directions, taking its average value.

This instrument is AC and DC dual-purpose, when not connected to AC power, the meter uses battery power supply, and when connected to AC, AC power is preferred. When the upper left corner of the meter header shows " ", it means that the battery voltage is insufficient and a new battery should be replaced. When the meter is not used for a long time, all the batteries should be removed to avoid rusting the instrument.

No, the grounding resistance tester is suitable for measuring the grounding resistance of various devices and measuring the conductor resistance value of low resistance in electric power, post and telecommunications, railway, communications, mining and other departments, and can also measure soil resistivity and ground voltage. Because the grounding resistance is relatively small (and the insulation resistance is relatively large (the minimum is 1m, the maximum can reach 500m or even infinity), because the grounding resistance tester can not test the insulation resistance, the insulation resistance should be measured using the insulation resistance meter (megohmmeter).

Wuhan Huatian Electric Power specializes in the production of grounding resistance testers, and the following is an introduction to the grounding loop resistance.

The electrical laboratory measures the resistance of the ground protection circuit according to all the necessary conditions. There are two types of tests, for acceptance and stage work, and periodic tests that are carried out during operation. However, unlike most other tests, there is an entire range of acceptable ranges for measuring the ground resistance of a circuit, based on many parameters.

Measurement of ground loop resistance.

First, an acceptance data is performed after the ground loop is installed with a power supply of up to 1000 V, which is calculated when the circuit is in close proximity to the substation. For single-phase and three-phase networks with voltages of 660-380 volts, 380-220 volts and 220-127 volts, respectively, the resistance value of the ground loop can be or 60 ohms.

Measure the ground loop resistance at regular intervals.

In turn, the resistance of the ground loop should be 60 ohms at 220-127 volts (three-phase - single-phase), 30 ohms at 380-220 volts, and 15 ohms at 660-380 volts. When taking measurements with the repetitive grounding conductors of the connection in mind, the resistance should not exceed and 8 ohms, respectively.

It is evident from the above that the resistance should not change with time. The resistance of the ground protection circuit is calculated using a voltmeter and an ammeter. However, the complete formula used to calculate the grounding electrode is very large and requires the accuracy of the parameters, so even a well-grounded ground loop may not be fully functional.

Respondent: Huatian Power.

Low-voltage electrical work practical subject 1: the use of grounding resistance meter.

Answer: To detect the grounding resistance, a grounding resistance measuring instrument is generally used to measure the grounding resistance. The ZC-8 Ground Resistance Measuring Instrument is a commonly used instrument for measuring ground resistance. It is composed of a hand-cranked generator, a current transformer, a slip wire resistor and a galvanometer, etc., and is equipped with accessories such as grounding probes and connecting wiresThe shape is similar to that of a megohmmeter.

It is commonly used to measure the ground resistance greater than , and the method is as follows. (1) Disconnect the connecting wire between the grounding wire and the electrical equipment housing. (2) Insert the current probe at a distance of 40m from the grounding body, insert the voltage probe at a distance of 20m from the grounding body, and insert the two pins vertically into the ground about 400mm.

3) connect the terminal post E of the instrument with the shortest connecting wire, connect the binding post p of the instrument with the voltage probe with the shorter connecting wire, connect the terminal post C of the instrument with the current probe with the longest connecting wire. (4) There are 3 gears for the instrument coarse adjustment knob, and the position of the coarse adjustment knob is selected according to the size of the measured grounding resistance.

5) Shake the handle evenly at a speed of 120r min, and when the gauge head hand deviates from the center, adjust the fine adjustment dial until the watch hand is in the center. (6) The pointer indication value of the fine adjustment dial and the magnification of the coarse adjustment knob are the measured ground resistance value.

If the reading of the fine adjustment dial is that the magnification of the coarse adjustment knob is 10, then the measured ground resistance is.

Question: I use ZC25-3 shake meter, how to measure the ground resistance.

The question means that I can't measure the ground resistance with this shaker, right?

Two-wire method: There must be a ground with a known good ground, such as a pen, etc., and the measured result is the sum of the resistance of the ground being measured and the ground being known. If the known ground is much smaller than the resistance of the ground to be measured, the measurement result can be used as the result of the ground survey, which is suitable for areas such as dense buildings or cement floors where the sealed pile cannot be driven, E+ES receives the ground to be measured, and H+S receives the known ground.

Replace the three-wire method for low ground resistance measurements and to eliminate the influence of the resistance of the measured cable on the measurement results. E and ES must be separately connected directly to the ground to be surveyed. This method is the most accurate of all ground resistance measurement methods.

Measurement Method:

1. Prepare 1 instrument, 1 instrument box, 4 auxiliary grounding rods, 4 test lines, 2 simple test lines, and 6 batteries.

2. Take out the ES3010E Ground Resistance Soil Resistivity Tester.

3. This time, a four-wire precision test grounding resistance is used (the following connections refer to this figure), and the default distance between the grounding rods is 5 meters.

4. The current of the grounding rod is extremely red.

5. The voltage of the grounding rod is extremely yellow.

6. Clamp the green and black to the grounding wire of the equipment at the same time.

7. Insert the corresponding color into the instrument interface respectively.

8. Rotate the switch to the grounding resistance gear RE gear, which is to measure the grounding resistance.

9. Press the red test key to start the test.

10. Obtain the grounding resistance, oh, the grounding condition at this time is good, and the measurement can be completed if the inspection is qualified.

Ground resistance test method.

1. Grounding resistance test requirements:

a.AC working grounding, grounding resistance should not be greater than 4;

b.Safe working grounding, grounding resistance should not be greater than 4;

c.DC working grounding, grounding resistance should be determined according to the specific requirements of the computer system;

d.The grounding resistance of lightning protection ground should not be greater than 10;

e.For shielding systems, if joint grounding is used, the grounding resistance should not be greater than 1.

2. Grounding resistance tester.

ZC-8 Grounding Resistance Tester is suitable for measuring the resistance value of various power systems, electrical equipment, lightning rods and other grounding devices. It is also possible to measure the resistance of low-resistance conductors and the resistivity of the soil.

3. The instrument work is composed of a hand-cranked generator, a current transformer, a slip wire resistor and a galvanometer, etc., all of which are installed in a plastic shell and a leather shell for easy carrying. The accessories include auxiliary probe wires, etc., which are packed in the accessory bag. The principle of operation is a reference voltage comparison formula.

5. Use and Operation.

1. The provisions of the wiring method when measuring the value of grounding resistance.

The E end of the instrument is connected to a 5m wire, the P end is connected to a 20m line, and the C end is connected to a 40m line, and the other end of the wire is connected to the ground electrode E of the DUT, the potential probe P and the current probe C, and E, P, and C should be kept in a straight line, and the spacing is 20m

When measuring greater than or equal to 1 ground resistance, the wiring connects the 2 E-terminal buttons on the meter together.

When the measurement of the grounding resistance is less than 1, the wiring connects the two E-end button wires on the instrument to the grounding body to be measured respectively to eliminate the additional error introduced by the resistance of the connected wires to the measurement results during measurement.

2. Steps.

All wiring on the end of the meter should be correct.

The meter connection should be in firm contact with the ground electrode E, the potential probe p and the current probe C.

After the meter is placed horizontally, adjust the mechanical zero position of the galvanometer and return to zero.

Set the "magnification switch" to the maximum magnification and gradually increase the speed of the crank to 150r min. When the galvanometer pointer is deflected in a certain direction, rotate the dial to return the galvanometer needle to the "0" point. At this time, the reading on the dial is multiplied by the magnification file, which is the measured resistance value.

If the galvanometer needle is still not balanced when the dial reading is less than 1, the magnification switch can be set to a lower magnification until it is fully balanced.

According to the function, it is mainly divided into: digital ground resistance tester, earth network ground resistance tester, clamp ground resistance tester mainly depends on which type you need!

How is ground resistance measured? You can measure this directly with a multi-ohmmeter.

Answer: Use a multimeter to measure the on-off file, which is a measurement mode that almost all multimeters have, which is used to measure the conduction (short circuit) of the line. Generally, it will be matched with a buzzer and LED light, and the buzzer will sound or the LED light will be on, indicating that the line is on.

1. When measuring, the needle of the black pen is in contact with the wall or the ground.

When the multimeter is dialed to the on/off gear, the internal circuit that is turned on is: the black watch pen is connected to the negative pole of the internal battery, the positive pole of the battery is connected to a small resistance, and the other end of the resistance is connected to the red watch pen. The internal tweeting circuit takes the trigger signal from the resistor.

If the resistance between the two table pens is short-circuited or small, then the voltage on the trigger resistor in the meter is higher, which triggers a chirp. If the resistance between the two stylus is large, then the voltage division of the internal trigger resistor in series is so small that the chirp cannot be triggered.

Hope it helps, dear

The grounding resistance measurement punch meter abandons the traditional manual power generation mode, adopts advanced medium and large-scale integrated circuits, applies DC AC conversion technology, and combines the three-terminal button and four-terminal button measurement methods into a new type of grounding resistance measuring instrument. The working principle is that the DC AC converter in the machine changes the DC into an AC low-frequency constant current, and the auxiliary grounding electrode C forms a loop with the measured object E, which generates an AC voltage drop on the measured object, and is sent to the AC amplifier for amplification through the auxiliary grounding electrode P, and is sent to the instrument display after detection. With the help of the ratio switch, three different limit values of 20 and 0 200 can be obtained.

The structure is made of high-strength aluminum alloy as the shell, and the circuit adopts phase-locked loop synchronous tracking detection method and switching capacitor filter to prevent power frequency and radio frequency interference, so that the instrument has good anti-interference ability. The DC AC conversion technology is used to convert the DC into AC low-frequency constant current, which is convenient for measurement. The auxiliary ground resistance is allowed to vary between 0 2k (rc) and 0 40k (rp) so as not to affect the measurement results.

Ground resistance gauges do not require manual balancing. The 3 (1 2) position liquid crystal display can measure the resistance of low-resistance conductors, soil resistivity, and AC voltage to ground in addition to measuring ground resistance. If the test loop is blocked, the meter shows "1" indicating overflow, which is in line with the usual measurement habits.

When storing and keeping this dosage form, attention should be paid to the ambient temperature and humidity, and it should be placed in a dry and ventilated place to avoid moisture, acid and alkali and corrosive gases. When measuring protective ground resistance, be sure to disconnect the connection point between the electrical equipment and the power supply. When the measured ground resistance is less than 1, use a special wire to connect to the grounding body, C2 on the outside and P2 on the inside

When measuring the grounding resistance of a large grounding grid, it cannot be measured by the general wiring method, and the buried insertion point can be selected according to the provisions of the ammeter and voltmeter measurement method. When measuring the ground resistance, it is best to measure it 3 or 4 times repeatedly in different directions, taking its average value. This instrument is AC-DC dual-purpose.

When the AC power is not connected, the instrument is powered by the battery, and when the AC power is connected, the AC power is preferred. When " " is displayed in the upper left corner of the meter, it means that the battery dispersion key voltage is insufficient and the battery should be replaced with a new one. When the instrument is not used for a long time, the battery should be removed to avoid rust of the instrument.