Grounding resistance tester how to short circuit test index is one of the important indicators to measure the safety performance of various electrical equipment. It is in the case of high current (25A or 10A) to measure the resistance of the butt circuit, but also the test of the index of the butt circuit to withstand high current, in order to avoid personal injury in the insulation performance decline (or damage).
How to use grounding resistance tester short circuit test method is as follows:
(1) Use grounding resistance tester to prepare work
1) Read the instruction manual of the grounding resistance measuring instrument, and fully understand the structure, performance and use method of the instrument.
2) Prepare necessary tools and all instrument accessories for measurement, and wipe the instrument and grounding probe clean, especially the grounding probe, be sure to clean up the dirt and rust stains on its surface that affect the conductivity.
3) Disconnect the connection point of the grounding main line and the grounding body or the connection point of all grounding branches on the grounding main line, so that the grounding body becomes independent from any connection relationship.
(2) Use grounding resistance tester to measure steps
1) insert the two probes into the ground 20m and 40m away from the ground along the radiation direction of the ground body, and the insertion depth is 400mm.
2) Place the grounding resistance measuring instrument flat near the grounding body and connect the wires as follows:
① With the shortest special wire grounding body and grounding measuring instrument wiring end "E1" (three-end button measuring instrument) or with C2, "short after the common end (four-end button measuring instrument).
② Connect the measuring probe (current probe) 40m away from the grounding body with the wiring button "C1" of the measuring instrument with the longest special wire.
③ Attach the measuring probe (potential probe) in the dispersion m from the earthing body to the wiring end "P1" of the measuring instrument with the remaining middle-length dedicated wire.
3) After placing the measuring instrument horizontally, check whether the pointer of the galvanometer points to the center line; otherwise, adjust the "zero regulator" to make the pointer of the measuring instrument point to the center line.
4) Set the "multiplier scale" (or coarse adjustment knob) to the maximum multiple, and slowly turn the handle of the generator (pointer begins to offset), and turn the "measuring scale plate" (or fine adjustment knob) to make the galvanometer pointer point to the center line.
5) When the pointer of the galvanometer is close to balance (the pointer is close to the center line), shake the handle to make the speed reach above 120r/min, and adjust the "measuring dial" to make the pointer point to the center line.
6) If the reading of "measuring scale dial" is too small (less than 1), it is difficult to read accurately, indicating that the multiplier scale multiple is too large. At this time, the "multiplier scale" should be placed at a smaller multiple, readjust the "measuring dial" so that the pointer points to the center line and an accurate reading is read.
7) Calculate the measurement result, that is, r = "multiplier scale" number x "measurement dial" reading.
