Views:174 Author:Site Editor Publish Time: 2020-11-27 Origin:Site
The appearance of the terminal block looks simple, but the terminal block must also undergo strict product verification tests and periodic production type experiments. This article mainly introduces the content, method, and judgment standard of the mechanical performance, electrical performance, and environmental performance test of the terminal.
The purpose of the torque test is to test whether the screw has sufficient mechanical strength to ensure that no slippage occurs during the process of crimping. If the screw is not broken or deformed after the test, and the screw head groove does not appear to be damaged that affects continued use, it is qualified.
The purpose of the crimping reliability test is to test whether the terminal can clamp the wire without excessively damaging the wire. Use terminals to connect wires of the specified type and rated cross-sectional area, hang a certain weight and rotate at a speed of 10 revolutions per minute (10 ± 2r/min) for 15 minutes. After the test, if the wire does not slide out of the terminal clamping piece or break near the clamping piece, the crimping reliability of the terminal is qualified. If there is a wire break or fall off the clamping mechanism of the terminal, it is unqualified.
The purpose of the pull test is to test whether the terminal can firmly clamp the wire between the metal surfaces. Use terminals to access wires of the specified type and rated cross-sectional area. Use a certain force (kg) to pull the wire toward the axis of the wire. Keep it for 1min. If the abnormal wire does not fall out of the terminal, it is qualified.
The purpose of the mechanical strength test is to test whether the terminal has sufficient mechanical strength, especially whether the shell of the terminal has sufficient mechanical strength. During the side test, one sample was put into the drum of the test equipment and rotated at a speed of 5 revolutions per minute. After 5 minutes, shut down and take out samples for observation. If the terminal is not damaged and the shell has no cracks, damage, etc., it is qualified.
The purpose of the mechanical endurance test is to test whether the elastic element of the terminal can withstand a certain number of plugging and unplugging or other mechanical operations used, such as the pressing and loosening of spring terminal buttons. If the tested elastic element is assembled into the terminal, the mechanical and electrical properties should still meet the requirements, it is qualified.
The electrical contact resistance test is to test the static contact performance of the terminal, that is, the contact resistance should not be greater than a certain value.
The power frequency withstands voltage test is to test whether the terminal shell should withstand the specified short-term power frequency overvoltage. During the test, no flashover or breakdown shall occur.
The impulse withstands voltage test is to test whether the terminal shell should withstand the specified transient overvoltage. There should be no destructive discharge during the test.
The voltage drop test is to test the dynamic contact performance of the terminal. The voltage drop should not exceed a certain value.
The temperature rise test means that when the test terminal is in normal use, the temperature rise cannot exceed the specified value. Generally, the UL standard stipulates that the temperature rise of the terminal after passing current cannot exceed 30 ℃ of the ambient temperature.
The electrical performance test is to test the reliability of the electrical performance of the screwless terminal in normal use. After the terminal is subjected to 192 cycles, its voltage drop in the 24th and last cycle shall not exceed a certain value.
The packaging vibration test is to simulate the ability of the terminal packaging to withstand vibration during transportation. After testing, the terminals in the package must not be affected or damaged.
The product vibration test is to simulate the ability of the terminal to withstand vibration during use. Fix the front and back, left and right, top and bottom of the terminal on the vibrating table in turn, and apply the specified analog quantity to the X, Y, and Z-axis directions of the terminal, and the terminal shall not be damaged after testing.
The limited fire test is to test the fire limited performance of the terminal material. During the test, clamp the standard sample on the holding seat of the instrument for testing, move the fire source to the specified position to ignite and burn, and remove the fire source after the specified time. If after the fire source is removed, the sample strip still burns or it is dripping ignites the cotton under the sample strip, the resistance is not qualified. If the sample strip extinguishes by itself after the fire source is removed, the flame limit is qualified.
The anti-aging test is to test whether the terminal can be used normally under a certain height. Place the terminal in an aging test box and apply a high temperature of 105 ℃ or 120 ℃ for 7 days. If the tested terminal is not aging, it is qualified.
The alternating damp heat test is to test whether the terminal can withstand the damp conditions that may occur in normal use.
The salt spray test is also to test whether the terminal can withstand the damp conditions that may occur in normal use. Only the metal parts of the terminal are tested individually. After the test, if the metal parts are corroded, they are unqualified.