JJG 366-1986 Grounding resistance meter trial verification regulations JJG366-1986 standard download decompression password: www.bzxz.net

Trial Verification Regulations for Ground Resistance Meters
JJG366—1486
Trial Verification Regulations for Ground Resistance Meters
Vcrificatian Regulation ot
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JJG 366—1986
This standard was approved by the State Bureau of Metrology on November 12, 1986, and has been implemented since September 12, 1987. Responsible unit: Shanghai Standard Measurement and Base Management Bureau
Drafting unit: Shanghai Municipal Measurement Technology Research Institute The technical provisions of this standard shall be interpreted by the State Bureau of Metrology. 458
Technical requirements
Verification policy
Setting verification method.
Processing of verification results and quick determination:
Related terms of rolling resistance meter
Trial verification procedures for grounding resistance meters
This regulation is applicable to new production and also to the effectiveness of grounding resistance meters used by management offices. This regulation is not applicable to grounding resistance meters for AC power grid and grounding resistance meters manufactured for special requirements (such as dielectric-proof grounding resistance meters). 1. Technical requirements
1. Three important signs
1.1 The brand or label of the grounding resistance meter should have the following main features: product name, model, size, and factory number:
name of manufacturer;
accuracy rating;
working position:
standard voltage
insulation test line voltage;
obvious E (test electrode), P (potential electrode), and C (transmission board) symbols on the connection terminals. 1.2 The grounding resistance meter should have a location for the calibration department to visit. 2
Allowable error
According to the type of grounding resistance meter, the accuracy level and the allowable error should not exceed the meter. Specified grade (n
Reading difference. (%)
No allowable error is expressed as error
Allowable error (%):
×100t
Maximum absolute error ():
Upper limit of measurement (2);
A——indicated value (0)
4——actual value).
3 Insulation resistance
A-An×100%
The insulation resistance between the grounding meter and the external party of the enterprise (or any part of the external shield of the insulation work) should not be less than ZhMn.
Line insulation strength
Connecting block ohmmeter line and metal external Between the shell (or any metal part on the insulating outer element), it should be able to withstand the actual frequency of -5H2 fiber wave AC 50V (effective value) for 1m without breakdown or leakage. The difference between the indicated value of the working position and the indicated value of the pump in the normal working position (not more than 2) (not more than 10) should not exceed the allowable error. The influence of the auxiliary grounding resistor on the two grounding resistors can be changed under certain conditions: 5002! 5 years: 2000±5%, 000±5% (the return rate should not be less than .25W): the difference in the indicated value should exceed the current requirements in Table 2. Table 2
Auxiliary grounding resistor Figure (they)
Will change the amount of the conditions (%:
To reduce the accuracy of the power supply, etc. 2
Two verification conditions
The ground resistance meter should be verified under the conditions specified in Table 3. Table 3
Environmental time overflow ratio (%)
[Generator speed (nia)
Working position (
For the battery power (V)
Input grid ground resistance (A
Verification according to the total accuracy of the ground resistance meter
The base value of the system must be less than the value specified by the manufacturer! The angle value of the network must be less than the value specified by the manufacturer? The medium-voltage cabinet specified by the manufacturer is in the simplified small line % bzxZ.net
500 ± 5
The total uncertainty of verification caused by daily standards, verification auxiliary equipment and environmental measures should not exceed the allowable error. 13. The value of the AC resistance box used as the standard (a DC drop test box with a time constant less than 1×10 can also be used) is generally 1 gate (1011021101110.1+0.01)0, and the power is not less than 0.25W. Its actual error (not the potential accuracy level of the test box) should not exceed 1/4 of the allowable error of the ground resistance meter being tested. The maximum range of ground resistance is measured using a megohmmeter with a DC voltage of 50OV, a measuring range of 10M and an accuracy level of 1.5.
11 The insulation strength test of the high-voltage test bench requires: 11.1 There is sufficient output power. The method of output power verification is to first connect the two output terminals of the high-voltage test bench (that is, to the load), and the voltage rises to 1/2 of the test voltage. Set it as 7, and then check the grounding meter. If the voltage drop is less than or equal to 0.1L at this time, it is considered that the voltage drop is sufficient. 11.2 The error of the test voltage is ±7.5%. 11.3
The high-voltage test bench can automatically cut off the power supply. The relay action current is 5m4 [this is the high voltage output current).
The power supply frequency is 45~6SHz
Three verification items and verification methods|| tt||The calibration types of the tt||connected resistance meter are shown in the calibration items in Table 4. 4
Calibration agent
External inspection
Battery current limit
Related
Use
Period
Risk determination item I[
Local note
Determined type
Drive battery current
Can be calibrated
External inspection book
The square root of the first series of requirements, check the shell of the tt||connected resistance meter for the necessary marks, whether there is a light chain on the shell, whether there is a click sound inside when tilting or not, whether the fingers should not bend, can ensure correct reading, the wiring should not be loose, and there should be a seal in place. In addition, the same instrument does not affect the measuring performance and the use of the meter : For the grounding meter that is in use and has been repaired, if it is found that its electrical safety has been seriously affected, it should be repaired before calibration. After the external inspection: the grounding resistance meter should be placed in the modified environmental conditions for at least 2 hours, and then the following calibration should be carried out:
14 Insulation level measurement
The grounding resistance meter will be measured with a megohmmeter with an accuracy level of 1.5 (DC voltage 500V: upper limit of the capacity is S[V]), and one end is connected to the grounding circuit to be tested. The other end is connected to the outer shell (or any point of the insulation! For a full year, the megohmmeter 1 reading is taken when the voltage is increased for 1min to 2min, and the line strength test is carried out.
The measuring end of the ground resistance meter under test is short-circuited, and one end of the two test ends of the test bench is connected to the grounding line of the test meter, and the other end is connected to any metal point on the metal insulation shell. Gradually rise to 500V for 1min, and the phenomenon of flying isolation is observed. The test is complete. 16 Basic error verification
16, 1 First determine the full test range. In this process, each line with mathematical division is verified one by one. Principles for determining the full test range:
16.1.1 The range must be any one of the most accurate numbers of the grounding meter under test. 16.1.2 According to the requirements of the inspection unit, the normal line diagram during the verification is as shown in Figure 1 and Figure 2, or according to the regulations of the manufacturer. Figure 2 - When the power supply is connected to the ground >10V, adjust the standard resistance box to align the finger card on the ground resistance meter with the scale line marked with valid numbers: the ground resistance meter with differential position meter, place the measuring potential at the set check point, adjust the standard resistance box decimal point to make the galvanometer on the connected meter point to zero, at this time the error of the ground resistance meter is: 2 = the meter indication value - the actual value of the standard resistance box: the unit is 16.2. Other recorded verifications
need to verify the measurement limit value in the measurement column, the actual error is 17 working position tube shadow verification
when determining the measurement system of each measurement code, Before the resistance meter is charged, the value of the auxiliary earth resistance value at each calibration is 10 degrees, and the value of the calibration value at the time of calibration is less than the value specified in Article 5: 8 auxiliary earth resistance test
In the measurement of each range of the calibration, the auxiliary earth resistance value is set at 02, 20002, and 500 respectively. The difference between the auxiliary earth resistance value and the calibration value at 5 o'clock will exceed the limit of the first phenomenon table. The data of the calibration station results are normalized according to the four five persons and the number of lessons. The regulations are as follows: 1.5 and 2.5 levels are normalized to 0.29;
5 levels are normalized to 0.5%
When judging whether the grounding resistance meter is qualified, the normalized index shall prevail. 0According to the test items specified in Table 3, the qualified products shall be tested; as long as one of the test items is qualified, the test result shall be notified, and the unqualified situation shall be noted in the test notice. 21The test result shall not be given in the test report or test result. 22The grounding resistance meter produced before the promulgation of the eighth regulation or imported from abroad shall be graded according to the test results and the technical requirements of this regulation. If the grade is less than the original grade, 23 the grounding resistance shall be stamped after the test: 24 The test period of the grounding resistance meter is generally 2 years. Terminology related to grounding resistance meter
Grounding meter (earth meter) is an instrument used to measure grounding resistance.
2 Grounding resistance
The resistance between the grounding conductor and the earth. When an AC current flows through the conductor, the potential of the conductor is divided by the test current, and the quotient is the grounding resistance. The voltage drop type grounding meter uses the grounding voltage drop divided by the measured current when the zero position is compared with the standard voltage. 5 The voltage drop type grounding meter is used to measure the grounding resistance. Allowable tolerance
The cost difference limit of measuring instruments under the condition of working thread, its verification terms can be found in G001-12 Verification Procedure for Measuring Instruments of the People's Republic of China "Common Terms and Definitions of Measuring Instruments"
Additional Notes:
The chief examiner of this verification procedure: Ding Wangen (Beijing Electric Power Testing Institute) The main contributor of this procedure: Zha Shuining (Shanghai Measurement Technology Research Institute) The additional drafter: Shan Junliang (Shanghai Measurement Technology Research Institute)
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