JJG 313-1994 Measuring current transformers JJG313-1994 Standard download decompression password: www.bzxz.net
This regulation applies to the verification of measuring current transformers of 0.001~1 level with a rated frequency of 50 (60) Hz, which are newly manufactured, in use and after repair.

Verification Regulation of Current Transformers for Measuring ServieeJJC 313-1994Verification Regulation of Current Transformers for Measuring ServieeJJC 313-1994Replacement of JG313-1983This verification regulation was approved on April 23, 1994 by the national technical advisory body and will be implemented from March 1, 1995Responsible unit: National Electricity Metering CenterDrafting unit: National High Voltage Metering CenterThe technical provisions of this regulation are issued and drafted by the drafting unitThe main drafter of this regulation:Wang Shouxin (National High Voltage Metering Station
No addition of drafters
Ren Yongkai (National High Voltage Metering Station)
Shang Qinghua (National High Voltage Metering Station)
Hu Liwu (Zhejiang Leyou Lanjing Furnace Factory) 402
Technical requirements
Verification items
Verification methods
Verification period
Processing of verification results·
Thanks 1 Verification record format
Appendix 3
Regular format on the back of the book
Record 3
6 Verification conclusion and notice format on the back
Verification procedures for measuring current transformers
Not applicable to the control of the effective current transformer (hereinafter referred to as current transformer) with a rated value of S (newly manufactured, used and treated). Technical requirements
No error limit
When the rated power, rated power factor and rated load are adjusted within 25%-10% of the rated load, the current transformer The current difference (ratio difference and phase difference) should not exceed the limit values ​​specified in the table. For 0.25-level and 0.5S-level inductors (rated secondary current is limited to 5A, and the error under 20% rated current needs to be measured), when the secondary load is between 25% and 100% of the rated load, the error under rated frequency should not exceed the error limits listed in Table 2. Table 1 Measures the mutual inductance of current at rated current in percentages under rated current. >: t0-
Time sensitivity under fixed current
Table 2 Current difference ratio for special use requirements
Percentage value under fixed power supply
0.75 ;U.3
Primary value under fixed power supply
For rated primary current of 5A and rated load of 5VA, the lower limit load is 2.5VA. 404
Note: (1) For rated secondary current of 4A, rated load of 4VA or 5VA, the lower limit load is 3.75VA. In the specification: must be effective.
(2) For non-standard products, it is allowed to make a determination according to the technical conditions specified by the brand. The calibration results should only be noted in the certificate (*Note: the calibration average condition
The actual error of the current transformer is formed by the near-line pool formed by connecting the lines and should not exceed the error limit values ​​listed in the above table. When testing current transformers, they must comply with the technical requirements of the regulations and the corresponding technical requirements. During the calibration, when current flows through the secondary winding of the sensor, it is strictly forbidden to disconnect the secondary circuit. 3.2 Calibration conditions bzxZ.net
4 Main equipment
4.1 Standard current transformer or other special current transformer (hereinafter referred to as standard device) The accuracy level and technical performance of the standard device shall meet the following requirements:
4.1.1 The standard device shall be two accuracy levels higher than the test sensor: the actual error shall not exceed the operating error limit of the test sensor. 4.
When the above conditions are met, a probe with a higher grade than the current transformer can also be selected as the standard. In this case, the deviation of the current sensor under test should be calculated by using the formula in 16.2 to correct the error of the standard. The deviation of 4.1.2 standard (the difference between the errors obtained when the current rises and falls twice) meets the limit values ​​in Table 3. 3. The difference limit of the current mutual confusion cycle of the standard is difficult to determine, so the main research is to determine the percentage of the current. 4.1.3 During the calibration period, the error change of the standard instrument shall not be greater than 13 of the error limit. The standard shall be certified by the statutory metrology agency with a secondary load of 20-123. The secondary load when used shall include the difference between the differential current support additional load and the color thickness marked on the certificate, which shall not exceed %. 4.2 The measurement error caused by the differential measurement device (usually a sensor calibrator) shall not exceed 1/1 of the difference value of the current mutual compensation device being tested. Among them, the current error caused by the sensitivity of the device is greater than 1/20: the full-scale error caused by the small division value is not greater than 1/5: the influence of the differential current measurement circuit secondary load on the current sensor reading is greater than 405
4.3 Monitoring ammeter
is the standard for determining the secondary circuit working current: the accuracy level of the current measurement should not be less than 15, and in all indication ranges, the internal impedance of the ammeter should remain unchanged: 4.4 Current
When the rated frequency is 50 (60) Hz and the temperature drop is (20 ± 5), the error of the active component and the passive component of the current load shall be between 5% and 120%. The error of the active component and the passive component of the current load shall not exceed 10% within the rated current range of 1% to 120% of the 5th level. When = 1, the residual active component shall not exceed 13% of the rated load. For every 10% change in ambient temperature, the load quotient The error change shall not exceed 2% (the product produced according to the original specification is allowed to be used under limited conditions): 4.5 Power supply and regulation equipment
The power supply and regulation equipment shall ensure that they have sufficient capacity and adjustment precision, and the power frequency shall be [50 + 3.3 (60 ± 0.6) Hz, and the waveform variation coefficient shall not exceed 5% 5 Environmental conditions
5.1 The operating temperature is 10-+35℃, and the relative humidity is not more than 80%. 5.2 The measurement error caused by the electromagnetic environment that is not related to the calibration work shall not be greater than 1/20 of the error limit of the current transformer being tested. The measurement error caused by the booster, regulator, high current inductor, etc. used for calibration work shall not be greater than 1/10 of the error limit of the current transformer being tested. 3. Verification items and verification methods
(Inspection items and procedures)
6.1 Appearance inspection:
6.2 Determination of insulation resistance:
6.3 Power frequency voltage test,
0.4 Relay polarity check:
6.5 Demagnetization;
6.6 Measurement of differential voltage
7 Outsourcing inspection
If there is any of the following defects, it will be inspected after a simple repair. 1.1 There is no plate or the necessary markings are missing on the plate: 7.2 The terminal is missing, damaged or unmarked: The through-type current detector has no electrical markings: 7.3 The multi-ratio current sensor has different current ratio wiring methods on the plate or surface: 7.4 Other defects that seriously affect the inspection work, 8 Final inspection of the tram
You can use a non-ohmmeter to measure the insulation resistance between each group and between the potential group and the ground. All measurements with a 501V megohmmeter are also The insulation between the secondary winding and the secondary winding and the ground is less than 5M2, and the power frequency voltage test is required. 9.1 The power frequency voltage test, including the power frequency withstand voltage test, must strictly abide by the safety work regulations. 9.1 The test items and test methods of the newly manufactured current transformers in the power system must comply with the provisions of GF4-311-1983 "Test Methods for High Voltage Electrical Equipment" 9.2 The newly manufactured current transformers (all faster windings or insulation) are not connected to the power system in the test room, and the upper frequency test items must comply with the provisions of BY7-1994 "Technical Cases for Current Transformation Solutions", and the test items must comply with the relevant parts of BY7-1994 "Technical Cases for Current Transformation Solutions", and the test items must comply with BY7-1994 "Technical Cases for Current Transformation Solutions". 9.3 For the inductors of the power system in operation (including those that have been repaired), the power frequency voltage test shall be carried out in accordance with the requirements of the handover and preventive test standards of the electrical equipment of the Ministry of Water Resources and Hydropower. 9.4 During the test period, the current transformers shall be tested at 80% of the rated voltage specified in HY1W71991 after a short period of use or when the user requires it. The test method shall refer to the individual rate test of GB311-1983.1 It is recommended to use a current sensor to check the polarity of the mirror group. Generally, the control equipment has a polarity indicator, and the polarity of the standard is known. When the carrier is connected according to the specified mark, if the polarity indicator of the calibrator is found to be activated and the cause is the transformer, it can be confirmed that the polarity of the test sample and the standard current sensor are reversed. 10.2 When the sensor used for inspection does not have a polarity indicator, other methods such as the AC method (or DC method) can be used to directly check the polarity of the mirror group. The reported polarity should be negative polarity. 11 Demagnetization
The best demagnetization method is the demagnetization method specified by the manufacturer on the nameplate or specified in the technical documents. If the manufacturer does not make any regulations, it can be demagnetized by a suitable method in the methods introduced here according to the actual situation.
11.1 Open circuit demagnetization method
Select one of the windings with the least load in the secondary (or secondary) system and use 10% of the rated secondary (or primary) load, and when all the windings are open circuit, steadily and slowly reduce the voltage. During the demagnetization process, the peak voltage meter connected to the two ends of the largest number of windings should be monitored. When the indicated value exceeds 2600V, the demagnetization should be carried out under a smaller current. 11.2 Closed circuit demagnetization method
Connect a current equivalent to 10-20 times the rated load (considering the load), pass a secondary current through the primary winding, and pass a specified current with a zero ramp rate of 1.2 times. After heating, the current transformer is gradually reduced to zero. When demagnetizing a current transformer with two or more secondary loads, if all the secondary loads are linked to the same iron core, one of the secondary loads is connected to the demagnetization current, and the remaining secondary windings are connected to the circuit. 12 Measurement during excitation
12.1 When measuring the difference, the appropriate standard instrument and measuring equipment shall be selected according to the accuracy level of the current transformer and the requirements of Article 4 of this regulation. However, no matter what measuring device is used, the following provisions shall be followed: The T end of the secondary winding is changed to the K end of the secondary winding, and the same-name measuring terminal of the secondary winding is defined as the corresponding measuring terminal. The same-name measuring terminals of the secondary winding of the current transformer to be controlled are connected together, and the output terminal of the current transformer is connected to the same terminal or indirectly grounded through a symmetrical branch (or any other method). The same-name measuring panels of the corresponding secondary windings are also connected together, and are connected to the ground potential of 1 or 10: but not directly to the ground.
12.2 Calibration circuit
12.2.1 Calibration circuit
When the constant current ratio of the inductor to be tested is 1, it can be determined according to the principle circuit of Figure 1. D has been published /1127-07 joint book
·Ship's comparison route
When the rated current of the standard current transformer is the same as that of the standard, it can be connected to the small line shown in Figure 5 for calibration, and the current can be increased by
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American fast electric drop book
To compare the residual circuit
Paste to check the current mutual
West 3 section of the heart current mutual inductance to check the current five-rate device of the North line I guarantee to come
Micro-control electric mutual inductance to open
Figure 4 uses the current to teach the comparison of a current mutual inductor or a brief 12.2.3 Use the level current sensor to control the comparison circuit of the general current transformer 12.2.4 Use the current comparator to check the comparison circuit of the general current transformer 12.2.5 Use the current comparison to grab the double-stage current sensor comparison circuit 12,2 .6 The comparison route of the symmetrical branch connection ratio in Figure 1 and Figure 6 is: L: 1 is the primary terminal of the thermal power inductor; K, K is the secondary terminal of the seven-way current sensor; T is the primary standard terminal on the mutual inductor test instrument, T, is the primary sensitive test terminal on the giant sensor calibrator; K is the inductor technical upgrade test instrument
electric comparison instrument
Xuying Physical Engineering
the strong station
electric point inductor
out of May Newton application only the specified bipolar current sensor comparison line calibrator under the differential current branch connection jump jump, 7 square load; V is the limit value of the meter: the heart rate meter: the switch: [is the wiring terminal; C is the adjustable capacitor; Mu is the primary compensation group of the comparator.
Test gate.1 Generally and above or when it is specified that the following circuit is built once, the circuit should be connected through a symmetrical branch (or other method) to a low voltage, until the meat is 6 meters high, first put the components in the appropriate position, fully adjust R and C, until the high impedance meter shows the minimum value of V, and the end is close to the ground potential, meeting the requirement of indirect grounding.
The result must not be symmetrical. When the test error is only 1/15 of the level difference, the symmetrical branch is not connected. The standard reduction
rush current
use 5 symmetrical branches to compare
the standard device has a primary compensation winding, the first end is connected to the primary pole, the end port is connected to the battery, and the other branch is not required during the three measurements
12.2. Under the premise of meeting the requirements of the fourth series of this regulation, it is allowed to use a different standard method to measure the error of the switchgear:
12.3 The current, load and power factor used in the error measurement are tested according to the conditions listed in Table 4. Generally, the standard is 2.0C1, 0 002, 3.C5. .nL,
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3.0C1,0 002,3.05.UL
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19,3,37,1(n.12
5. 20. 105
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industry other transformer limit value
biaoleqiao
chart. The secondary power city EA is set at 5VA ton%, the lower limit is 2.5VA: when locating the newly manufactured static electricity or the current transformer in the hall: under the rated power factor, add the rated load and: /4 rated load (the rated secondary current is 51, the rated load is 5VA, the lower limit load is 2.5VA) measure each port 1% (for S class) 5%, 2 0%, 100% and 120% rated current: When the calibrator approves the newly manufactured current transformer of the same model, after the metering machine or the relevant competent department receives the registration, the error can be reduced under the premise of confirming that it meets the requirements of the regulations. 12.4 In addition to the initial determination, the user is allowed to select only one of the partial rate fixed values ​​such as %-.8~1 according to the actual use of the user. 8? Apply for the calibration: but not the light risk of the rate due to the clause, please refer to the detailed work of the 12.5 variable ratio electric construction industry, the current ratio of the new rated 12.6 When testing the current mutual inductance of the through-hole current sensor, if the manufacturer does not allow the through-hole to be located, the distribution of the through-hole conductors shall be restricted during the test. If the error changes due to the change of the conductor position, the data with the larger error shall be used as the data, and the error values ​​obtained by artificially changing the conductor position shall be considered invalid: For through-hole current sensors above 10kA, when testing for the first time, the through-hole conductors must be symmetrically distributed and The asymmetric distribution and connection mode are tested, and the data are small. If the standard is met, the test can be sent for inspection later. According to the production requirements, only one of the connection modes can be tested, and it should be noted in the report. 12.7 The measurement efficiency of each differential measurement point of the test instrument is higher than 0.2 level [including 0.2 level; for the multi-current sensor in the standard state, each ampere only controls the error of each measurement point when the current is reduced, and the rest only measure the error when the current is not increased (except for the primary current equal to or less than 1A).
For current transformers used for general measurement (1.2 level and below), only the current rise and fall of the current need to be measured at the same time.
The rise and fall of the current must be carried out steadily and steadily. 4. Verification cycle
3. Verification cycle is determined according to different conditions.
13.1. For current transformers used for standard measurement, the verification cycle is set at 2 years. For current transformers used only for measurement, the technical factors can be used to determine the position of the current transformer. The total calibration period is determined by the environmental conditions and frequency of use, and is generally 2 to 4 years. 11.2 For an electric sensor using 0.2 level as standard and 1: (including 0.2 level) as standard, if the error is not more than 100% of the error when the last calibration result is compared with any of the previous 2 calibration results, the calibration period can be extended by 50% of the original, that is, the calibration period is 3 years. If the fourth calibration is still not satisfactory, 1.The inspection cycle can still be extended, that is, the inspection cycle is 4 years. For current transformers used as standards, if the error exceeds its error limit within a verification period, the inspection cycle is shortened to [years,
13.3 The first inspection of current transformers equipped with calibration may not be called a separate periodic inspection, and it is allowed to be recorded together with the previous inspection
5. Processing of inspection results
14. The inspection data should be recorded in the prescribed format and requirements. C, 3 For current transformers with a grade higher than the standard grade listed in this regulation, at least 2 calibration records shall be kept, and the rest shall at least 1 calibration record shall be kept. If the current transformers with a grade other than the standard grade listed in this regulation meet the requirements of this regulation, they shall be rated at a lower grade with a standard grade similar to that specified in this regulation. Error calculation of the tested current transformer: When the standard grade is higher than the grade of the tested current transformer and the upper filter is higher, the following formula shall be used for calculation: %) or (10 \
$,-3[ or (10-\rad)
formula, and 6,
the ratio difference and phase difference of the tested current transformer: and the upper and lower ratio difference readings measured are calculated as the average value, for current sensors of level 0.2 and above, the readings measured when the current rises; 5-the upper and lower currents are calculated as the average value of the required phase difference, for current sensors below level 0.2, the readings obtained when the current rises as the current rises. 16.2 When the standard device is one level higher than the tested current transformer, calculate according to the following formula: =, (%) or (10\)
8,-o,+an 'or (10 \rad?
in the formula, the ratio of the standard instrument in the calibration certificate and the position difference (3)
17 to judge whether the error of the sensor under test exceeds the error limit given in 1, the peak of the error should be found in Table 5, and the level of identification can be abandoned. Only the accuracy source can be used. (?
City Accuracy Level
China Society
18 For current sensors that have passed the verification, a certificate of inspection shall be issued or a verification mark shall be marked. t.5
18.1 The error values ​​under various loads used during the verification shall be given on the verification certificate. The maximum error value shall also be given as the standard.
18.2 Only current sensors that meet the technical requirements of this regulation for all current ratios can be filled in as the standard for the second grade on the cover of the verification certificate; for the partial current and special current of the verification, the error values ​​under various loads used during the verification shall be given as the standard. The control results of the current transformer should only be marked on the cover, and the verification situation and conclusions should be specifically indicated in the conclusion and explanation column on the back. 19. For current transformers that fail the verification, a verification conclusion notice should be issued. If the verification results are poor, the verification certificate can be issued according to the level that can be achieved after the account opening request and can be downgraded. 200.2 level and above electric transformers, after verification, a seal is added. 21. Current transformers that fail the verification according to this procedure are allowed to be exported, and the name of the manufacturer is: an
This is the year of the institute
Manufacturer name
Export! No.
Appendix 1 Verification record format
Heart flow sensor verification record
Accuracy
Rated primary voltage
Rated secondary voltage
Rated power factor account
Assumed load
Rated voltage..
Verification period
Valid until
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