Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T7570
1994-12-09
JB/T75701994
This standard specifies the use environment conditions of outdoor three-phase AC high-voltage automatic reclosers. Terms, basic classification, rated parameters, design and structure, type test, factory test, marking, packaging, transportation, storage, etc. This standard applies to outdoor AC high-voltage automatic reclosers in three-phase systems with rated voltage of 10kV and frequency of 50Hz. This standard does not apply to the reclosers used in places with fire, explosion hazard, chemical corrosion and severe vibration. Note: If no explanation is given, the "recloser" in this standard refers to the outdoor AC high-voltage automatic recloser. 2 Reference standards
GB311.1~311.6 Insulation coordination high-voltage test method for high-voltage power transmission and transformation equipment CB 11022
GB 11023
GB 1984
CB 763
GB 2706
GB3309
GB11604
GB 5465. 2
GB5273
GB 2423
GB 6162
CB 6905
Environmental conditions for use
Ambient air desaturation
Upper limit: +40℃
General technical cases for high-voltage switchgear
Guidelines for testing the sealing of sulfur hexafluoride gas in high-voltage switchgearAC high-voltage circuit breakers
Heating of AC high-voltage electrical appliances during long-term operationAC high-voltage electrical appliances dynamic thermal stability test methodsMechanical tests of high-voltage switchgear at room temperatureRadio interference measurement of high-voltage electrical appliancesPaper methodDiagram symbols for electrical equipment
Terminals for transformers, high-voltage electrical appliances and bushingsBasic environmental test specifications for electrical productsElectrical interference test for static relays and protective devicesGuidelines for the management and detection of sulfur hexafluoride gas in electrical equipmentLower limit, -40℃ (-45℃), -30 (-35)Note, the values in brackets are for users and manufacturers to negotiate and select.Daily variation: Daily variation range classification: 25, 32K. 3.2 Altitude
1000, 3000 m.
3.3 Wind pressure
3.4 Creepage distance
Creeppage distance shall be in accordance with Table 1.
1994-12-09 Tumor
1995-06-01 Small cable
External insulation pollution
(grade)
JB/T7570
Note: Creepage distance is the ratio of the creepage distance of the external insulation of the power equipment to the highest voltage of the equipment. 3.5 Others
The influence of condensation, rain, sudden temperature change and sunshine on the product shall be considered. 4 Terminology
AC high voltage automatic close
Minimum nominal current ratio
High voltage switchgear with self-control protection function (no external energy required) that can automatically open and close in the AC line according to the predetermined opening and closing sequence, and then automatically reset or lock. 4.2 Automatic operation
The control device automatically completes the operation in the predetermined sequence. 4.3 Unit operation
Refers to the recloser performing a combined operation after a breaking operation, but the last breaking in the operation sequence is also regarded as a previous operation.
4.4 Instantaneous opening operation
Opening operation without any delay inside the recloser control device, also known as fast operation. 4.5 Delayed opening operation
Opening operation that sends an operation signal after a predetermined delay inside the recloser control, also known as slow operation. 4.6 Time-current characteristic line
The inverse time relationship curve between the fault flow time of the recloser and the interrupted current (the typical curve is shown in Figure 1). 100
4.61 Instantaneous (fast) time-current curve i
Setting current multiple
Typical time-current characteristic curve
In instantaneous opening operation, the time-current curve is drawn with the maximum value of the fault flow time under a given breaking current. A product has only 2
4.6.2 Delay (slow) time-current line JB/T7570
In delayed opening operation, the time-current curve is drawn with the average value of the fault flow time under a given breaking current: a product can have multiple lines.
4.7 Closing lock
The recloser contacts are fed to the split position, and the closing function cannot be realized. 4.8 Opening lock
Locks the recloser contacts in the closed position, making the opening function impossible. 4.9 Closing interval
Refers to the time from the last separation of the recloser contacts to the first contact of the next reclosing. 4.10 Reset time
The time required for the system to return to its initial state. 4.11 Series opening recloser
A recloser that provides the necessary energy to open the main contacts when the main circuit current exceeding the specified value flows through the entire coil. 4.12 Parallel opening recloser
A recloser that opens the contacts by releasing a certain energy storage device when the opening control device and the fuse separator do not directly obtain energy from the power circuit.
4.13 Hydraulically controlled recloser
A recloser that uses a hydraulic mechanism to control the opening and reclosing intervals and record the number of operations. 4.14 Electronically controlled recloser
A recloser that uses electronic circuits to control the time-current characteristics, opening current, operation sequence and closing and disconnecting. 4.15 Minimum current value of the main circuit for reliable start-up and disconnection of the recloser. 5 Basic classification
Recloser classification according to Table 2
Arc extinguishing location
Installation point
Control method
Rated parameters
Rated voltage and maximum voltage:
New insulation water section,
Rated rate;
Rated current:
Rated minimum starting current;
Rated short-time withstand (thermal stability) current:
Rated peak withstand (dynamic stability) current; Rated short-circuit duration (thermal compensation) time:
Rated short-circuit breaking current:
Rated short-circuit closing current
Rated operating voltage;
Oil; vacuum, hexavalent Nordic
sample, curved
liquid electronic
Rated operating sequence.
6.1 Rated voltage/high voltage
10/11. 5(12. 0) kV.
6.2 Rated insulation level
JB/T7570
Insulation to ground and between the ends and the roots shall conform to the specifications in Table 3. Table 3
Tentative voltage H
6.3 Rated frequency
50Hz.
6.4 Rated current
200, 400, 630 A.
6.5 Rated minimum starting current
Impulse withstand voltage
1.2/50μg
Power frequency current 1min
The rated minimum starting current of the electronic control recloser is 2 times the rated current of the interconnection coil, with a 10% difference kv allowed
The minimum starting current of the electronic control recloser can be adjusted within the range that meets the requirements of the technical conditions, and the error shall not exceed 10%. 6.G Rated short-time withstand current
The rated short-time withstand current is equal to the rated short-circuit breaking current, see 6.9. 6.7 Rated peak withstand current
The rated peak withstand current is equal to the rated short-circuit making current, see 6.10. 6.8 Rated short-circuit duration
The rated short-circuit duration is divided into 2 and 4 levels. For reclosers equipped with a trip coil, the short-circuit duration must be specified. However, when the recloser is operated according to its rated operation order and the tripping setting is at the slowest speed, the recloser should be able to pass the rated short-circuit breaking current 4 times in a row during the breaking time. 6.9 Rated short-circuit breaking current
The effective value of the AC component of the rated short-circuit breaking current is selected from the following values: 3.15, 6.3, 8, 10). 12.516kA.
The percentage of the DC component of the rated short-circuit breaking current is generally determined by the value in Figure 2. 100
Time interval t(rns) from the start of short-circuit current 80
Figure 2 Relationship between DC component percentage and time (minimum opening time) 90
Rated short-circuit closing current
JB/T7570
The rated short-circuit closing current peak of the recloser (1) is .5 times the effective value of the AC component of its rated short-circuit breaking current. 6.11 Rated operating voltage
The high-voltage closing line of the recloser should be able to operate under the rated voltage of the recloser group|±【5%】. 6.12 Rated operation sequence
The operation sequence of the recloser must be:
Open-Close Open-t2-Open-t3-Close Open-t4, where t·ts, t, is the closing and isolating, and may not be equal in the same sequence. However, in the rated operation sequence, t:·t2., it should be the minimum value that can be adjusted to each voltage, and there should be at least two quick opening operations. Rated transient recovery voltage (when the output terminal is short-circuited) 13
The rated transient recovery voltage is expressed by the two-parameter method, and the specified value of the transient recovery voltage in the parameter table is as shown in Table 1. Table 4 Rated voltage/maximum voltage Sub-break current Percentage First opening current u,—kV2/3 U(maximum voltage); k→Amplitude coefficient: F. Equivalent frequency Note: When the maximum voltage is 1kV, the transient fast return voltage is specified. Please refer to Table 1 for the corresponding parameter conversion, 6. Specified parameter coordination The rated parameter coordination adopted for the recloser test is listed in Table 5 and Table 6. Table 5 Minimum split current and short-circuit breaking current of hydraulically controlled recloser Minimum starting current of split line A Reserve reference Recloser Vacuum Hexafluoride 7 Design and structure Rated current JB/T7570 Table 6 Rated current of recloser Rated symmetrical short-circuit breaking current In addition to meeting the requirements of GB11022, it shall also meet the following requirements: 7. 1 The grounding of the recloser shall comply with Article 6.3 of GB11022.
7.2 Terminals
Short-circuit current unit operation times
Unit operation
Total number of operations
The type and size of the terminals of the recloser shall comply with the provisions of CB5273 and shall be able to withstand the following static tensile forces without damaging its reliability and current carrying capacity. The static safety factor shall not be less than 3.2. Longitudinal horizontal tensile force FhAt500N,
Transverse horizontal tensile force FhAt250N
Vertical force (upward and downward) F: 300 N.
7.3 Opening and closing position indication
In addition to the auxiliary switch indicating the opening and closing position, the operating mechanism or recloser should have an easily observable mechanical indicator indicating the opening and closing of the recloser.
7.4 Marking
The recloser should have obvious power supply side or load side markings. The protective current transformer is installed on the power supply side of the recloser, and the metering current transformer is installed on the negative side of the recloser.
7.5 Interchangeability
Parts, wearing parts and spare parts produced according to the same drawing should be interchangeable. 7. 6 Lifting
The upper part of the recloser box should be equipped with a lifting ring or hook for easy lifting. Its position should be designed so that the recloser can be kept down when lifting. And avoid friction between the lifting rope and other parts (bushing, operating handle, etc.). The box should be easy to remove and easy to repair. 7.7 Synchronicity requirements of each pole
When there is no special requirement for the synchronous operation of each pole, the difference in closing and closing time shall not exceed 10ms: the difference in time between the poles shall not exceed 5m5.6
7.8 Requirements for secondary circuits
JB/T7570
The secondary circuit design of the recloser should be resistant to electromagnetic interference. 7. 9 Requirements for the box
The box and its auxiliary structures are made of anti-corrosion materials, or have an anti-corrosion surface layer. There should be no pits on the surface of the box and auxiliary devices for water accumulation. The box should have a support or foundation frame that is convenient for installation on a column or rack. 7, 10 Counter
The recloser shall be equipped with a counter indicating the total number of operations, and the counter shall be easily observable in the operating state. 7.11 Requirements for heating
7.11.1 When designing the structure of the recloser, the adverse effects of outdoor sunlight radiation, the increase of contact voltage during operation and pollution migration shall be fully considered, and a certain margin shall be left for temperature opening.
7.11.2 The temperature rise of the components and additional equipment (except electric heaters) of the operating mechanism that carry current for a long time shall not exceed the values specified in GB 763 under the following circumstances: The line voltage of the electromagnetic and undervoltage release is the highest voltage: a.
When the overcurrent release coil powered by the current sensor passes 220% of the rated current. b.
7.11.3 For the components and additional equipment of the short-time current-carrying workpieces in the operating mechanism, when the ambient air temperature is not higher than +40°C, the temperature rise measured instantly after the operation is completed under the following conditions shall not exceed the values specified in Table 7: 8
Maximum 2$#
If there is a device that can automatically cut off the circuit at the end of the operation, then operate continuously for 10 times at a constant voltage, and the interval between each operation is not less than 10 seconds. If there is no device that can automatically cut off the circuit at the end of the operation, then energize at rated voltage for 15 seconds. Table 7
Allowable temperature rise of short-time current-carrying components of operating mechanism
7.12 Insulation requirements for high-voltage closing lines Component name and specifications
Insulation of electromagnet: Class A
Insulation of electromagnet wire: Class E
Insulation of electromagnet coil: Class B
Insulation of electromagnet coil: Class F
Insulation of electromagnet wire: Class H
Insulation parts: Class C
Contact parts of interlocking connector and terminal
Allowable temperature rise of short-time working K
High-voltage closing line of the close-coupler should be able to withstand impulse voltage of 60 kV. The insulation to ground should be able to withstand power frequency voltage of 42 kV1 min and impulse voltage of 75 kV. k.
7.13 Requirements for operating handles
7. 13. 1 The length of the manual operating handle and the single-arm lever shall not exceed 350 mm, and the rotation angle shall not exceed 150°. 7.13.2 The operating mechanism and the direction of movement shall be clearly marked. 7.14 Other requirements
7.14.1 The operating mechanism of the recloser shall have anti-interference performance. 7.14.2 The operating hole of the operating handle shall be dustproof, moisture-proof, waterproof and prevent foreign objects from entering. 7.[4.3 When the recloser is disconnected due to a short-circuit fault, the design of the recloser must ensure that it will not be reclosed in vain. JB/T75701994
7.14.【The electronic components used in the control device shall be strictly screened before assembly, and the method shall be carried out in accordance with the relevant provisions of GB2423.
7.15 Additional requirements for oil reclosers
. a. The recloser should be filled with lubricant that meets the requirements of the relevant standards or product technical conditions; b. The recloser should have devices for filling, discharging and extracting oil samples! c. The recloser should have a safety valve (or other exhaust channel) and an easily observable oil level indicator: d. The discharge hole or safety valve of the oil recloser should be designed so that it will not cause electrical breakdown when carrying oil or exhausting gas. The discharge space should not endanger the electrical equipment and personal safety, and the discharge hole should be able to prevent foreign matter from entering. 7.16 Additional requirements for its vacuum chamber
The vacuum arc chamber equipped with the recloser should meet the requirements of the relevant standards. After leaving the factory, the vacuum arc chamber shall be stored for 20 years under the storage conditions specified by the manufacturer, and its vacuum degree shall not be lower than 6.66×10-Pb. The contact pressure of the vacuum recloser contact under the minimum contact stroke shall be specified in the specific product technical conditions. c. When the vacuum interrupter is insulated with gas or oil, the gas and oil shall meet the corresponding requirements. 7.17 Additional requirements for sulfur hexafluoride reclosers a. The permissible moisture content of sulfur hexafluoride gas shall not exceed 150 (volume ratio) pPmh. The annual gas rate of sulfur hexafluoride gas shall not exceed 1%, and may not exceed 2% after consultation with the user: C. The sulfur hexafluoride recloser shall be equipped with a charging and discharging joint! d. The sulfur hexafluoride recloser shall be equipped with a gas pressure monitoring device and a device for reporting the upper and lower limits of the sulfur hexafluoride gas pressure and shall be locked when it exceeds the specified value.
8 Type test
8.1 Type test criteria
All operating conditions that the recloser can reach when operating in the system shall be accurately verified by test. Therefore, these working conditions should be included in the type test content of the recloser. The test products for type test should be consistent with the product technical conditions and drawings. All type test results should be recorded in the type test report, which should include sufficient data to prove whether it complies with this standard. The recloser should be type tested in the following cases. a. New products:
Products for trial production in the factory
When the product has major changes in design, process or materials used, corresponding type tests should be carried out: c. Mass-produced products should be subjected to overflow, mechanical test, time-current characteristics and 100% rated short-circuit current opening every 8 years. d.
Break and close test. Other items can also be carried out when necessary. The type test of the recloser can be carried out separately on two test pieces. 8.2
Type test items
Continuous withstand voltage test:
Temperature rise test:
Main circuit resistance measurement:
Mechanical test:
Load current breaking and gas water content plate measurement under zero gauge pressure of sulfur hexafluoride recloser; e.
Minimum starting current test;
Time-current characteristic test!
Dynamic and thermal stability test:
Short circuit breaking and closing test;
J. Sealing and anti-static test
k. Environmental test of control device:
I. Transport vibration test of control device:
, control device and anti-electromagnetic interference ability test, 8.3 General requirements of test
JB/T75701994
8.3.1 Test condition: The test must be carried out before the product of this model is put into operation in the power grid, and a new recloser should be selected as the test product. 8.3.2 Installation of the test product, the installation method of the test product should meet the normal operation case required by the design. If its normal operation is equipped with control. Auxiliary devices, the recloser must be equipped with these devices for testing. 8.3.3 Grounding of the test product: All grounding parts of the recloser and its control device should have an additional grounding. 8.3.4 Power supply frequency, the test power supply adopts 50Hz (soil 5%) stopped sine wave. 8.4 Insulation test
8.4.1 Pressure-applied parts, pressure-withstand test of recloser See Table 7 of G11022 for pressure-applied parts. For commercial voltage closing coil impulse withstand voltage, both ends of the wire should be positively polarized in turn, and the other end should be grounded.
84.2 Lightning impulse withstand voltage test: When conducting lightning impulse withstand voltage test on recloser, it shall be conducted in accordance with the provisions of Article 7.1.6 of GB11022. Both ends of high voltage closing coil shall be subjected to impulse withstand voltage three times in positive polarity according to the values specified in Article 7.12 of this standard, and shall not be broken down or flashed over. 8.4.3 The power frequency withstand voltage test shall be carried out in accordance with the provisions of Article 7.1.7 of GB11022. The withstand voltage value shall be in accordance with the provisions of Table 3 of Article 6.2 of this standard. 8.4.4 After the rated short-circuit breaking current test, the insulation test shall be carried out in accordance with the requirements of Table 3 according to the breaking sequence and number specified in the standard. For vacuum direct-acting reclosers, the impulse withstand voltage value may be reduced to 80% of the specified value after consultation and agreement with the user. 8.4.5 The hexafluoride alkali recloser shall be able to withstand the high voltage to the ground and between the breaks for 5 minutes at zero pressure. 8.4.6 The operating mechanism and auxiliary circuit shall be subjected to the withstand test of 2000V power voltage for 1 minute as specified in Article 7.1.10 of GB11022. 8. 5 Temperature rise test
8.5.1 Temperature rise test of the main circuit
The temperature rise test of the recloser shall be carried out in accordance with the requirements of GB763, but the ambient air temperature during the test shall not be lower than 10°C. Temperature rise test shall be conducted before and after mechanical life test.
8.5.2 Temperature rise test of operating mechanism and auxiliary circuit The temperature rise test of current-carrying part and line of recloser mechanism shall be conducted in accordance with the requirements of Article 7.11. 8.6 Measurement of main circuit resistance
The difference of main circuit resistance measured at ambient air temperature before and after temperature rise test of recloser mechanical life test shall not be greater than 20% of the value measured before temperature rise. The main circuit resistance before and after temperature rise test after mechanical life test shall not exceed the technical requirements. 8.7 Mechanical lock test
The mechanical test method of recloser shall comply with the relevant provisions of GB3309. 8.2.1 Test conditions
The mechanical test of recloser shall be conducted under rated, maximum and minimum operating voltage and greater than minimum starting current at both ends of closing line. 8.7.2 Requirements for test products
The test products of mechanical test shall include recloser body and all attached components, and shall be evaluated as a whole. The connection and medium conditions of the test product's operating control power supply should be consistent with the operating conditions. 8.7.3 Mechanical durability test
8.7.3.1 Characteristic parameters recorded before and after mechanical test The characteristic parameters that should be recorded and tested before and after mechanical test include: travel, overtravel, opening distance, closing time, separation time, separation time, separation time, separation time, separation time, separation time difference, separation time difference, separation speed and other mechanical characteristics and parameters that need to be measured as specified in the product technical parts. 8.7.3.2 In addition to meeting the relevant provisions of GB3309 during and after mechanical test, the time-current characteristics of the recloser should meet the relevant provisions of this standard, and it should be reliable and automatic.
8.7.4 Mechanical operation test
JB/T7570
The purpose of mechanical operation test is to check the operating performance of the product under the specified operating conditions and the correctness of the closing, separation and rated operation sequence.
The mechanical operation test is carried out in accordance with the provisions of Table 8. Table 8
Operation sequence
Close-t.-Open
Open. ··Close-Open. tClose
Open—8—Close-Open—0—One—Open—T.—One operation voltage
Highest value
Rated value
Lowest valuewwW.bzxz.Net
Cheek positioning
Rated value
Rated value
Companion: D In the table, t is the interval between two operations: specified by the product technical conditions. 》 is the minimum reclosing interval specified in the product technical conditions, and the closing and opening operation time is determined by the product time-current characteristics. 8.7.5 Mechanical life test
Number of unit operations to be performed
The purpose of the mechanical life test is to verify whether the tested recloser can withstand the specified number of opening and closing operations under the specified mechanical characteristics and without replacing parts and components, and to assess the stability of the product's mechanical operation. In addition to meeting the relevant requirements of Chapter 5 of GB3309, the following provisions shall also be met. The recloser shall be subjected to at least 2000 consecutive unit operation test cycles at room temperature. During the test, no mechanical adjustment or repair of the test product is allowed. However, it is allowed to install the test product in the specified position in the manufacturer's product manual. Between two specified test cycles, the test product shall be lubricated and the test product exposed and tightened. The recloser under test shall be adjusted to the maximum allowable number of unit operations. The reclosing interval is adjustable and shall be adjusted to the designed minimum reclosing interval. After the test, inspection shall be carried out in accordance with 8.7.3. All of them shall comply with the provisions of GB3309 and product technical conditions. For the frequency-prohibited operation recloser and sulfur dioxide recloser, perform 5000 (or 3×2000) unit operations. For the vacuum recloser, perform 5×2000 unit operations continuously. The rated operating sequence of the recloser shall be as shown in Table 9. Table 9 Operation sequence and operating parameters of mechanical life test of recloser type t||Minimum value
Maximum value
Rated value
Minimum value
Maximum value
Rated value
Maximum value
Note: (The time interval between two rated operation sequences shall be implemented in accordance with the product technical conditions. Operation sequence number
250(3X125)
750(3X250)
250(3×125)
5×125
5×250
5×125
If the recloser is equipped with a remote control auxiliary device, it can be operated by the remote electric control unit and can be operated by the manual reverse unit. 8. 8 Load interruption and gas moisture measurement of hexafluorocarbon combiner under zero gauge pressure B.8.1 Load electrical interruption test under zero gauge pressure is carried out in single-phase three-phase circuit, co55=0.65~0.75. 10
Unit operation number
1G0ocsco
3000(3060)
1600(1500)
JB/T75701994
8.8.2 Technical requirements for measuring water content of hexafluorocarbon gas The sum test method shall be in accordance with the provisions of 7.1 and 8.1 of GB8905. 8” Minimum starting current test
When testing in accordance with Article 8.3 and the following provisions, the recloser shall quickly break the rated minimum starting current or the minimum starting current of each gear (electronic control recloser). The current value is allowed to have an error of ±10%. 89.1 Test National Road
The recloser should be connected in series with the low voltage AC power supply circuit (such as National 3)
current source
8. 9.2 Test procedure
Figure 3 Minimum starting current test circuit
Apply pressure to the recloser to be disconnected instantaneously, so that it generates an initial current less than 80% of the specified minimum starting current value, and quickly increase it to 80% of the minimum starting current. Then slowly increase the current to the rated minimum starting current at a certain speed, and the current increase time shall not be less than 10?. Continue to increase at the same speed until the voltage is connected to the recloser action, and record the maximum current displayed on the antimeter. 8.10 Time-current characteristic test
8.10.1 Test conditions: The time-current characteristic test can be carried out simultaneously with the machine core test and the breaking test. The method should be carried out in accordance with Article 8.3 and the following provisions
The current range for which data is to be collected is from the minimum starting current to the specified short-circuit breaking current, and the sampling shall not be less than 6. Each sample shall be repeated for no less than 6 times, and the ratio of the maximum to the minimum time deviation in the 6 results shall not be greater than 1.25. The oil temperature in the recloser with a hydraulic timer shall be 20 ± 2 °C. 8.10.2 Test procedure: The time-current characteristic test shall be carried out in accordance with the following requirements. 8.10.2.1 Contact separation time-current characteristic test: The contact separation time-current characteristic test shall be carried out under any voltage not greater than the highest voltage of the recloser. The setting of the test circuit shall ensure that the current passing through the recloser is constant. 8.10.2.2 Fault through-current time-current characteristic test; Fault through-current time-current characteristic data shall be measured by one of the following methods. Method 1: Add the arcing time to the contact separation time obtained in 8.10.2.1. The arcing time can be obtained from the breaking test. Method 2: Measure the breaking time from the oscillogram of the opening test. 8.10.2.3 The measurement of current in the time-current characteristic test shall be carried out in accordance with the following requirements: a. Current with a duration of more than 19 s may be measured with a standard ammeter. Note: A standard ammeter adjusted to prevent the pointer from bumping too much should be used to improve the measurement accuracy. b. Current with a duration of less than 1 s may be measured with an oscilloscope or other suitable instrument. The short-circuited AC component containing a DC component shall be converted to a constant condition in order to draw the time curve. 8.10.2.4 The measurement of time in the time-current characteristic test shall be carried out in accordance with the following requirements. 8.10. For times above 1 s, a stopwatch, timer or other suitable instrument may be used. b. For times of 1 to 10 s, a synchronous timer or other suitable instrument may be used. . For times of less than 1 day, an oscilloscope or other suitable instrument may be used. 8.10.2.5 Representation of standard time-current curve data: The test results shall be plotted on a logarithmic coordinate paper. 11
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.