Varistor Test Flow
Varistor test flow
1, test range
Quality and product needs advanced technology, also need advanced testing equipment. In Ya Xun, we are equipped with advanced testing equipment, to ensure that all products can meet your requirements, varistor is an overvoltage protection element, must go through a variety of parameters test, our company has developed the following various test standards: the use of varistor conditions, electrical performance, mechanical properties and environmental performance and other aspects of the technical requirements and pilot projects, also provides the acceptance of varistor standards.
This standard applies to our experiment with varistor acceptance, periodic verification, the whole performance test.
Environmental testing of electrical and electronic products GB / T 2423.18
Environmental testing of electrical and electronic products GB / T 2423.28-2005
Environmental testing of electrical and electronic products GB / T 2423.32-2008
Electrotechnical and electronic products - Ignition test GB / T 5169.11-2006
Varistors for Electronic Equipment GB / T 10193-1997
AC metering equipment GB / T 17215.211-2006
GB / T2828.1 Count Sampling Inspection Procedure
2, Test Tools
High and low temperature alternating hot and humid chamber
Salt spray test chamber
Vernier caliper
Pressure tester
Lightning protection device tester
Lightning surge tester
Searing wire tester
3,Test Conditions
Unless otherwise specified, all tests and measurements shall be carried out under the following environmental conditions:
Temperature: 15 ℃ ~ 35 ℃;
Relative humidity: 25% to 75%;
Air pressure: 86kPa ~ 106kPa.
4, Parameter Item Test:
(1), Limiting Voltage (Vc)
The limiting voltage of the varistor shall comply with the relevant technical requirements of its detailed technical specification.
(2), Varistor Voltage (V1mA)
The varistor voltage of the varistor shall comply with the relevant technical requirements of its detailed technical specification.
(3), Leakage Current (IL)
The leakage current of the varistor should conform to the relevant technical requirements of its detailed technical specification.
(4), Capacitance (a Cmax) (applicable to Full Performance Test)
The capacitance of the varistor should meet the relevant technical requirements of its detailed technical specifications.
(5), Current Impulse Stability (for full performance test)
The varistor should be able to withstand the impact of "1 pulse current (2ms) A" or "1 pulse current (10 / 1000μs) A" and "40 pulse current (8 / 20μs) A".
(6), The Limit Current Impulse Withstand Capability (for Full Performance Test)
The varistor should be able to withstand the impact of "1 pulse current (8 / 20μs) A".
(7), Insulation Package Pressure Capacity
Varistor insulation package pressure resistance should be consistent with its detailed technical specifications of the relevant technical requirements.
(8), Insulation Package Flame Retardant Requirements
Insulation package of varistor should be in accordance with the requirements of this test specification 5.6.2 glow wire test, the glow wire temperature is 850 ° C.
(9), Mechanical Performance Requirements
The varistor shall be subjected to the strength of the lead-out according to the requirements of Test Specification 5.7, impact test and vibration test,After the test varistor appearance should not have any mechanical damage, limit voltage and varistor rate of change should not exceed 5%.
(10), The Performance Requirements Of The Environment (for Full Performance Test)
Varistor for the test of this specification 5.9 high temperature storage, low temperature storage, high temperature and humidity, salt spray test. After the test, appearance should not have any mechanical damage, limit voltage and varistor rate of change should be less than 10%。
(11), Impact Life Requirements (for full performance test)
Varistor The test of the impact of life test 5.10, the number of tests should not be less than 5000 times.
5, Electrical Test
(1), limiting voltage test
Test direction for both sides to limit the voltage, apply a lightning current pulse current of 8 / 20μs to the varistor. current peaks refer to the nominal pulse current in Appendix B, allowable deviation of 10% applying a point to the end of the lead-out of the varistor, while applying surge current, measure the peak voltage of the limit voltage.
(2), Pressure-Sensitive Voltage Test
The voltage-sensitive voltage test direction is two-way. the varistor is fixed on a non-corroded fixture, the pressure-sensitive resistor through a DC reference current 1mA, test the varistor voltage value, test time should be as short as possible, so that the temperature of the varistor resistors did not increase significantly during the test.
(3), Capacitance Test
Test the capacitance in the standard atmospheric conditions of the test, the test frequency is 1 kHz, unless otherwise specified, should use a signal level of less than 1Vr.m.s, and no DC bias. the measured capacitance shall comply with the requirements of 4.4.3.
(4), Leakage Current Test
Leakage current test direction for the two directions. 25 ℃ when the maximum voltage applied to the varistor voltage, test its leakage current, the measured leakage current shall comply with the requirements of 4.4.4.
(5), Lightning Current Shock
The impact of "40 pulse current (8 / 20μs) A" in Appendix B is applied to the varistor, in one direction after the impact of 20 times, and then another direction of the impact of 20 times, the time interval between two adjacent shocks is 90s.
during the test process varistor should not have breakdown, flashover, the appearance should not have any mechanical damage. 40 shocks, the varistor at room temperature to restore 2h, measuring the limiting voltage, its rate of change should be less than 10%; measure the varistor voltage, the rate of change should be less than 10%.
(6), Square Wave Current Impact
The impact of "1 pulse current (2ms) A" or "1 pulse current (10 / 1000μs) A" in Appendix B is applied to the varistor, the direction of any, after the test, varistor should not have breakdown, flashover, the appearance should not have any mechanical damage. after the impact, the varistor at room temperature to restore 2h, measure the varistor voltage, the rate of change should be less than 10%.
(7), Hit The Current Tolerance Test
The varistor was placed in a thermostatic chamber with a temperature of (85 ± 3), apply the maximum continuous AC voltage Ua.c.r.m.s (total harmonic distortion rate less than 5%) specified in the detailed technical specification, the allowable deviation of the voltage is ± 0.2%. at 2h and 1000h of the experiment, the current value flowing through the varistor is determined online. 1000h measured value should be less than 2h measured value of 2 times.
Remove the varistor from the chamber, visual inspection of varistors, there should be no obvious mechanical damage. at room temperature to restore 2h, measuring the limiting voltage, the rate of change should be less than 10%; measure the varistor voltage, the rate of change should be less than 10%.
(8), Insulation Package Pressure Test
With the metal ball method for pressure test, the insulating package of the varistor is embedded in a metal ball of diameter (1.6 ± 0.2) mm, the metal ball is used as an electrode,the two leads of the varistor are connected together as the other electrode.
Apply the test voltage specified in the technical specification between the metal ball and the lead-out of the varistor. the voltage should rise from 0 to the upper limit of the test voltage 2500V, keep 1min, throughout the trial, there should be no breakdown, arcing, flashover and other phenomena.