Here is how to use the ND2571 earth resistance tester
1 Measuring earth resistance (as shown in figure 1)
· Along the measured earth electrode E. (C2, P2), the potential probe P1 and the current probe C1, 20 meters apart in a straight line, so that the potential probe is in the middle position of E and C, and insert probe into the earth as required.
· Use special wires to connect terminals E (C2, P2), P1 and C1 of the earth resistance meter to the probe location.
· Turn the power switch of the earth resistance meter to “ON”, select the appropriate speed and press the button once. The speed light will come on. The value displayed on the LCD screen of the screen. the head of the meter is the measured earth resistance.
2. Measuring soil resistivity (as shown in Figure 2)
· During measurement, insert four probes thealong a straight line in the soil to be measured and make each probe The spacing of the pins is equal, the distance between each spacing is L, and the depth of the probe in the soil should be L/20 cm. Use wires to connect the four probes to terminals C1, P1, P2 and C2. respectively. If the resistance value measured by the earth resistance meter is R, the soil resistivity is calculated according to the following formula:
Ф=2πRL
Where: Ф—soil resistivity ( Ω· cm)
L—The distance between probes (cm)
R—The earth resistance meter reading (Ω)
Measured by This method Soil resistivity can be approximated as the average resistivity of the soil in the area between the buried probes.
· Probes used to measure soil georesistance and resistivity generally use aluminum alloy tubes or round steels with a diameter of 25 mm and a length of 0.5 to 1m.
3. Measurement of theconductor resistance (Figure 3)
4. Earth Voltage Measuring
Measuring wiring is as shown in Figure 1. Unplug. sheet C1. Keep the plug between E and P1, turn on the earth voltage (EV) level, the indicator light will be on and the value read on the meter will be the AC earth voltage value between E and P1.
5. After the measurement is completed, press the power button “OFF” to turn off the instrument.
1. Front panel description (serial number matches the serial number on the panel layout drawing)
(1) “Power” switch, press this switch is powered on.
(2) “Reset” button: Press this button to stop the test. The output test current is cut off and the green light turns off. If the instrument is in an over-resistance alarm state, press this button to clear the alarm before proceeding to the next test.
(3) “Start” button: Turns onz the power switch and the instrument will be in reset state. Preset the resistance value in advance and connect the load. Press this button once to adjust the test current to perform the resistance test. At this time, the green test light will illuminate. If this button is pressed without a load connected, an open circuit alarm will occur. This can be understood as an open circuit condition between the object under test and the test instrument, which is not properly connected.
(4) “Manual/Timer” switch: Press this switch, the instrument is in the timing test state, at this time, set (7) the timer to the value required.The timer test can be performed for the duration of the test; press this switch and the instrument is in the manual test state. At this time (7), the timer will not run and the instrument must be manually “reset” after testing.is finished.
(5) “Preset/Measurement” switch: Press this switch and the instrument is in the resistance preset state. At this time, adjust the “Preset Resistance” potentiometer to the required resistance setting value and test if. the resistance value of the tested component is greater than or equal to the preset value, the instrument will be in the resistance limit exceeded alarm state, indicating that the tested component is not qualified. The alarm can be cleared by pressing the reset button. .
(6) “Preset Resistance”: Corresponding to (5) “Preset/Measurement” switch, the resistance setting value increases clockwise and decreases counterclockwise clockwise.
(7) “Timer”: Dial switch during timing test, timing time can be set from 1-99s. When the synchronization test is notWhen used, the switch (4) can be placed in "manual". " position.
(8) Multi-function display: used to display "timing time", "tested key resistance value" and "test current value"
(9) “Test” Green Light: Press the start button and the green light will turn on, indicating the start of the test Before that, the load must be connected and the resistance value must be preset
(10) “Overlimit” yellow light: When the resistance value of the component under test is greater than or equal to the resistance setting value, the instrument generates an overresistance alarm. This yellow light is on. indicating that the tested component is not passed at this time, press the “Reset” button to cancel the alarm signal
(11) “Test current” adjustment: adjust this regulator. voltage to adjust the output voltage, thereby adjusting the test current into the loadto the specified value.
(12) “Test” terminal: This is the test current output terminal, consisting of four large and small red and black binding terminals. The load is connected to the four terminals via test leads. The large terminal is the current sampling test terminal and the small terminal is the voltage sampling test terminal on the resistor. The red and black terminals have no impact on the test.
2. Rear panel description (serial number matches the serial number on the panel layout drawing)
(1) “Power” jack: AC220V input, 50Hz power supply, built-in 5A fuse /8A One.
(2) “Earth” end: The protective earth end of the instrument, which is connected to the instrument shell. Use AVR × 0.75 stranded wire to connect this end to ground.
(3) Nameplate: identifies the unique number and date of manufacture of the instrumentument
3. Operating Procedures(1) Turn on the power and turn on the unit. switch, the instrument will be in the To Test state.
(2) Press the “Preset/Measurement” button, adjust the preset resistance value to the required value and pop up the “Preset/Measurement” button.
(3) Connect the load, click the “Start” button, adjust the “Current Output” to adjust the test current to the specified value, then the test can be carried out at this time - there. the “mΩ” meter will display the measured value of the component resistance. If the resistance of the device under test is equal to or greater than the preset resistance value, the instrument will trigger an over-resistance alarm, the buzzer will sound, the yellow over-limit indicator light will light up, and current will be output. it is cut, it means that the tested part is not qualified. Press the reset button to cancel the alarm before theThe next test can be performed. If the test current exceeds 30A, an audible overcurrent warning will also occur. Since the loads are not exactly the same, the "current setting" must be adjusted to the required test current during testing.
(4) If a timing test is performed, set the timing switch to the corresponding value between 1s and 99s and press the “manual/timing” switch to the timing position. If you are not using scheduled tests, simply place the "manual/timed" switch in the manual position.