Solid state relays are a new type of non-contact switching device composed entirely of solid-state electronic components, which use the switching characteristics of electronic components (such as switching transistors, thyristors and other semiconductor devices) to achieve the purpose of non-contact spark-free circuit on and off, so also known as "non-contact switch". Solid-state relay is a four-terminal active device, two of the terminals for the input control, and the other two for the output controlled terminal. It is suitable for driving high-power switching actuators, and is more reliable than electromagnetic relays, and has no contacts, long life, fast, and little interference with the outside world.
A, solid state relay common causes of failure
1, the coil frequently disconnected causes: whether the solid state relay with ultrasonic cleaning, whether the coil is added to the voltage and other reasons will make the coil disconnected.
2, the coil power supply is not enough: first, you need to confirm the solid state relay coil voltage. If the voltage provided to the coil is lower than the action voltage, the contacts will not operate.
3, the cause of the coil polarity reversal: check whether the diode configured in the relay is polarity reversed, so that the contacts do not operate.
4, AC solid state relay coil, if applied DC voltage, heating coil will also be easy to burn, if applied to the DC relay coil on the AC voltage, also easy to burn.
5, if the relay is energized for a long time, it will lead to coil heating and insulation deterioration.
Second, the solid state relay common fault solutions
1、The simplest and most effective method is to use a new solid state relay.
2, The other is to determine the voltage of the coil to avoid the coil provides less than the action voltage.
3、Check if the polarity is reversed.
4, reasonable implementation of solid state relay coil energization time, if you really can not avoid or coordination, then you can use a non-excitation design of solid state relay to competent work.
5. Make sure that the energizing time of the solid state relay coil is reasonable. If it is not reasonable, then a solid state relay with a non-excitation design can be used.
