SU575583A1 - Method for measuring resistance of large complex earthing - Google Patents

Description

(54) METHOD OF MEASURING THE RESISTANCE OF A COMPLEX EARTHER

SIGNIFICANT SIZES

They are pressed for 10–15 cm in place, the food is supposed to be installed on a concentrated grounding conductor. If the resistance of the probe affects the quality of measurements, the soil around it will be deepened or moistened. The boundary of the zone of the zero 1cile is found by the indications of a voltmeter 4 when the probe 5 is removed from the measured earthing switch 6. If the area of the grounding is known, these measurements are not made, and the beginning of the zero potential zone is calculated.

Measuring from the found point approximately 40 m deep into the zone of zero potential, an auxiliary centered earthing switch is installed.

In order to measure the resistance of the auxiliary lumped earthing (point "a in fig. 2), lumpy potential (point" b in fig. 2) and current (point "in fig. 2) earthing switches are also installed. If for the installation of earthing switches, single vertical earthing switches with a depth of 6 m each are used, the distances between the points "а v" (b, "a and" c) are chosen equal to 30 m, and the distance between the points "b and" in about 15 m. If the depth of the electrodes is more than 6 m, the indicated distances must be at least 30 m.

Next, using the MS-80 or M-416 device, the resistance of the auxiliary concentrated earthing switch is measured. Taking into account the above arrangement (Fig. 2), the measurement error is determined by the accuracy of the measuring instrument.

Further according to the scheme of FIG. 3, the complex earthing is measured taking into account the previously measured resistance of the auxiliary earthing; electric line 1, oil switch 2, conductor 3, ammeter 4, complex earthing switch 5, conductor 6, ammeter 7, conductor 8, auxiliary earthing switch 9 are used.

The results of simultaneous readings of ammeters 4 and 7, as well as the previously measured resistances of conductors 6 and 8, make it possible to calculate the sought resistance of a complex earthing according to the formula:

Re - (R94-R8) -R5. 2

where RS is the resistance of a complex grounding gel 6;

11 - current, and.hme |) e1111H | st am11e) meter () m 7;

1; GOK, measured by a.MiiepMeipoM 4;

Ra is the resistance of all grounding ground 9;

Re-resistance of conductor 8;

Ri is the resistance of the conductors.

In order to reduce the height due to the finite value of the resistance of the conductors used, ammeters must be located in the immediate vicinity of the measured complex ground.

In order to periodically monitor the resistance of complex grounding stations of power stations, substations, mines, mines, it is necessary to once establish the boundary of the current spreading area by these grounding conductors (provided that no additional grounding elements are attached to them) and overhaul additional grounding outside this zone for multiple use

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Claims (2)

1. Ground resistance meter M-416. Passport, technical description and operating instructions. Megommetr plant, Uman, 1972. 2. Lurie A. I. Testing of the grounding devices of electrical installations, Gosenergonzdat. L., M., 1950, p. 35-44. ig.1