1) Grounding resistance tester;
(2) galvanometer;
(3) galvanometer pointer;
(4) x0 1, x1, x10 are grounding resistance value gear multiple selection knob;
(5) 0~10 test resistance value knob;
(6) Grounding resistance indicator;
The test method of the ZZC29B-2 type shake table is as follows:
(1) When measuring the grounding resistance of the two terminals of E-E, short-circuit with chrome-plated copper plate and connect it to the 5m long pure copper wire with the instrument. The other end of the wire is connected to the grounding body test point to be tested. on. When measuring the resistance of the shield, the chrome-plated copper plate should be loosened, one E terminal should be connected to the grounding body, and the other E terminal should be shielded.
(2) The P-pillar is connected to the 20m pure copper wire of the instrument, and the other end of the wire is connected to the pin.
(3) The C-pillar is connected to the 40m pure copper wire of the instrument, and the other end of the wire is connected to the pin 2.
2 Technical requirements for grounding resistance tester settings
(1) The grounding resistance tester should be placed 1 to 3 m away from the test point, and the placement should be stable and easy to operate.
(2) The terminals of each terminal must be in good contact and firmly connected.
(3) The two grounding pins should be placed at a position of 20m and 40m from the left and right sides of the grounding body to be tested. If the two pins are connected by a straight line, the grounding body to be tested should be basically on this line.
(4) Do not replace other pure copper wires of 5m, 20m, 40m length with the instrument.
(5) If the grounding resistance tester is centered, the angle between the two pins and the tester should be at least 120°, and it should not be set in the same direction.
(6) The soil set by the two pins must be solid and cannot be placed in the mud, backfill, tree roots, grass and other places.
(7) The grounding resistance test can only be carried out after 7 sunny days after the rain.
(8) The grounding body to be tested should be treated with rust removal to ensure reliable electrical connection.
3 Operating principle of grounding resistance tester
(1) The measurement of the grounding resistance value is started only after the tester is set to meet the specifications.
(2) Before the measurement, the grounding resistance gear knob should be rotated in the maximum gear position, ie x10 gear position. The adjustment grounding resistance value knob should be placed in the 6~7Ω position.
(3) Rotate the handle slowly. If the pointer of the galvanometer is quickly deflected to the right from the 0 balance point in the middle, the original range selection is too large, and the gear can be selected to the x1 position. If the deflection direction is as before, the The gear selection is transferred to the x0 1 gear.
(4) After selecting by step (3), slowly rotate the handle, and the pointer of the galvanometer is offset from the 0 balance point to the right. The grounding resistance value is still too large. When the handle is slowly rotated, the grounding resistance knob should be slowly clockwise. Rotate, when the oximeter pointer returns to 0, gradually increase the handle speed, so that the handle speed reaches 120 rpm, the grounding resistance at this time
Multiplying the indicated resistance value by a multiple of the gear position is to measure the grounding resistance of the grounding body. If the pointer of the galvanometer is slowly deflected to the left, the resistance of the grounding resistance knob is less than the actual grounding resistance, and it can be rotated counterclockwise slowly to increase the indication value of the meter resistance.
(5) If the handle of the galvanometer is beep when the handle is rotated slowly, it means that the ground soil of the two ground pins is not dense or there is a bad contact of a joint. In this case, check the ground of the two pins or Each joint.
(6) When the grounding resistance of the static pressure pile is measured by the grounding resistance measuring instrument, it is normal that the pointer of the galvanometer has a slight left and right swing at 0 o'clock.
(7) When the pointer of the galvanometer moves slowly to the 0 balance point, the handle of the instrument generator can be accelerated, and the rated speed of the handle is 120 rpm. It is strictly forbidden to speed up the rotation of the handle when the pointer of the galvanometer still has a large deflection.
(8) After the measuring instrument is used, the resistance position should be placed at the maximum position, that is, the x10 position. Finish the three test leads that are configured with the meter, clean the dirt on the two pins, and pack the bags.
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