How much is the domestic voltage breakdown tester

Thermosetting molding compound voltage breakdown testerThe clauses in the following documents are referred to as clauses in this section of GB/T 1408. Any referenced document marked with a date shall not be subject to any subsequent amendments or revisions to this section, except for errata. However, parties to agreements based on this section are encouraged to explore the possibility of using versions of these documents. The version of any referenced document without a date is applicable to this section

GB/T 1981.2-2003 Coatings for Electrical Insulation - Part 2: Test Methods (IEC 60464 "2:2001, IDT)

GB/T 7113.2-2005 Test Methods for Insulated Hoses (IEC 60684-2:1997, MOD)

GB/T 10580-2003 Standard conditions for solid insulation materials before and during testing (IEC 60212: 1971, IDT) ISO 293:1986 Plastic thermoplastic materials compression molded test specimens

ISO 294-1: 1996 Injection molding methods for plastic thermoplastic material specimens - Part 1: General principles, multi-purpose molded parts and strip specimens

ISO 294-3: 1996 Injection molding method for thermoplastic material specimens - Part 3: Small plates ISO 295:1991 Plastic thermosetting material compression molding specimens

ISO 10724:1994 Plastics Thermosetting molding compounds Injection molded multipurpose test specimens

IEC 60296: 2003 Specification for unused mineral insulating oils for transformers and switches

IEC 60455-2, 1998 Orange resin based reactive composites for electrical insulation - Part 2: Test methods IEC 60674-2: 1988 Plastic films for electrical purposes - Part 2: Test methods

The following definitions apply to this section.

When the electrical breakdown sample is subjected to electrical stress, its insulation performance is severely damaged, and the resulting test field current causes the corresponding circuit breaker to operate

Note: Breakdown is usually caused by partial discharge in the gas or liquid medium surrounding the sample and the electrode, resulting in damage to the sample at the edge of the smaller electrode (or two electrodes of equal diameter)

When the flashover sample and the gas or liquid medium around the electrode are subjected to electrical stress, their insulation performance is lost, and the resulting test circuit current causes the corresponding circuit breaker to operate. Note: The appearance of carbide channels or the breakdown of the penetrating sample can be used to distinguish whether the test is breakdown or flashover.

The breakdown voltage is the voltage at which the sample experiences breakdown under specified test conditions in a continuous boost test. In the step-by-step pressure test, the sample can withstandVoltage, that is, at this voltage level, the sample does not experience breakdown throughout the entire time.

The electrical strength is the quotient of the breakdown voltage and the distance between the two electrodes to which the voltage is applied under specified test conditions. Unless otherwise specified, the distance between the two test electrodes should be measured according to the provisions of section 5.4 of this part. The significance of the experiment is that the electrical strength test results obtained in this section can be used to detect changes or deviations in performance relative to normal values caused by process changes, aging conditions, or other manufacturing or environmental conditions, and are rarely used to directly determine the performance status of insulation materials in practical applications. The electrical strength test values of materials can be influenced by various factors, such as:

The state of the specimen a) the thickness and uniformity of the specimen, and the presence of mechanical stress;

b) Sample pretreatment, especially drying and impregnation processes;

c) Whether there are pores, moisture, or other impurities present.

Test condition a) Frequency of applied voltage, shaping and boosting speed or time;

b) Environmental temperature, air pressure, and humidity;

c) Electrode shape, electrode size, and thermal conductivity;

Thermosetting molding compound voltage breakdown tester

In ASTM standards, these electrodes areoftenUsed or referenced. It is not recommended to use electrodes for materials other than flat materials, except for Type 5 electrodes. Other electrodes used by ASTM or electrodes recognized by both the buyer and seller but not listed in this table are also suitable for evaluating the measured materials.

B electrodes are usually made of brass or stainless steel. Reference should be made to the standards for controlling the tested material to determine its suitability.

The surface of the C electrode should be polished and any debris left from the previous test should be removed.

Refer to appropriate standards to determine the load force of the installed upper electrode. Unless otherwise specified, the upper electrode should weigh 50 ± 2g.

Refer to appropriate standards to determine gradients with appropriate spacing.

FIEC publication 243-1 provides type 6 electrodes for determining flat plate materials. For the concentricity of electrodes, they are not as important as Type 1 and Type 2 electrodes.

As long as the inner diameter of the circular edge of the test sample is greater than 15mm, other diameters can also be used.

The H7 electrode, as described in Note G, is given in IEC Publication 243-1 and should be measured parallel to the surface

ASTM D149-2009 Test Method for Dielectric Breakdown Voltage

6.1.3 According to 12.2, the control of the variable low-voltage source can change the pressure of the power supply, so that the synthesized test voltage is smooth, uniform, without excess or transient. Under no circumstances should the peak voltage exceed 1.48 times the effective value of the displayed voltage. Motor driven controllers are more suitable for fast testing (see 12.2.1) or slow testing (see 12.2.3).

6.1.4 Install a disconnect device on the power supply that can operate within three cycles. This device disconnects the voltage source equipment from the power supply equipment to protect the voltage source from the impact of sample breakdown causing equipment overload. If a continuous current is maintained after rupture, it will cause unnecessary combustion of the test sample, pitting of the electrode, and contamination of the liquid environmental medium.

6.1.5 The circuit breaker equipment should have detection elements located on the secondary boosting transformer that can adjust the current, so as to adjust and arrange according to the properties of the test sample to detect the test current. Set up detection components to cope with the breakdown current of the test sample defined in 12.3.

6.1.6 The current setting has a significant impact on the test results. The setting should be high enough to prevent transient voltage, such as partial discharge, from passing through the circuit breaker. If it is not high enough, it will break through the excessively burned test sample and cause damage to the electrodes. The optimized current setting may not be applicable to all test samples, depending on the specific usage of the material and the purpose of the test. It is necessary to test the given test samples with multiple current settings. The electrode region has a significant impact on the selection of current settings.

6.1.7 The current sensing element of the test sample should be located at the front end of the step-up transformer. Calibrate the current detection scale according to the test sample current.

6.1.8 The current control response should be carefully set. If the control is set too high, there will be no response when breakdown occurs. If set too low, it will respond to leakage current, capacitor current, or partial discharge current (corona), or to magnetizing current when the detection element is located at the front end. Voltage measurement - equipped with a voltmeter to determine the effective value of the test voltage. A voltmeter capable of reading peak values should be used, and dividing the reading by is the effective value. The overall error of the voltage measurement circuit cannot exceed 5% of the measured value. In addition, regardless of the speed used, the hysteresis rate of the voltmeter response time shall not exceed 1% of the entire process.

6.2.1 Measure voltage by connecting a voltmeter or potential transformer to the test sample electrode, or to a separate voltmeter coil on the transformer. The latter connection method will not affect the load of the step-up transformer.

6.2.2 Requirements for Voltage MeterThe readable voltage should be greater than the breakdown voltage in order to accurately read and record the breakdown voltage.

6.3 Electrode - For a given test sample structure, the breakdown voltage will still vary significantly due to the geometric shape and installation position of the test electrode. For this reason, it is important to specify the electrodes used in this testing method and provide an explanation in the report.

6.3.1 The document referring to this testing method provides a detailed explanation of the electrodes listed in Table 1. If there are no specified electrodes, suitable electrodes should be selected from Table 1, or in cases where standard electrodes cannot be used due to the properties or structure of the tested material, other electrodes recognized by both parties should be used. Some examples of special electrodes can be found in Appendix X2. In any case, the electrodes used should be explained in the report.

The entire plane of electrodes 1 to 4 and type 6 in Table 1 should be in contact with the test sample.

6.3.3 The test sample using a Type 7 electrode should be placed inside the electrode during testing, with a distance of no less than 15mm from the edge of the electrode. In most cases, when using a Type 7 electrode for testing, the electrode surface should be in a vertical position. The testing of horizontally placed electrodes cannot be directly compared with the testing of vertically placed electrodes, especially for testing in liquid phase environment media.

6.3.4 Keep the electrode surface clean and smooth, and remove any debris left by previous tests. If the electrode surface is rough, the electrode should be replaced in a timely manner.

6.3.5 It is very important to maintain the specific structure and smoothness of the electrode during the initial production and subsequent surface repair of the electrode. The flatness and surface smoothness of the electrode surface should ensure that the entire area of the electrode can be in close contact with the test sample. When testing very thin materials, surface smoothness will be particularly important, as inappropriate electrode surfaces can cause physical damage to the test material. When repairing the surface, the transition between the electrode surface and a specific edge radius cannot be changed.

6.3.6 Regardless of the difference in size or shape, the electrode located at the stress concentration point, usually the larger one with a radius, should have a ground potential.

6.3.7 In some specific liquid-phase metal electrodes, electrode foils, metal balls, water or conductive coated electrodes will be used. It should be recognized that this results in significant differences between the obtained results and those obtained with other types of electrodes.