1. Reasons for some failures of solid state relay coils:

1. The reason why the coil often disconnects: whether ultrasonic waves are used to clean the solid-state relay, or an overvoltage is added to the coil, which may cause the coil to disconnect.

2. The cause of the failure of insufficient power provided by the coil: First, the voltage of the solid-state relay coil needs to be confirmed. If the voltage supplying the coil is less than the operating voltage, the contact will not operate.

3. The cause of the fault of reverse polarity of the coil: Check whether the diode inside the relay has reverse polarity, which will cause the contact to not operate.

4. The reason for the error in AC and DC power supply of the coil: If a DC voltage is added to the solid-state relay coil of the AC coil, the coil will heat up, which is likely to cause burnout. Similarly, if the relay of the DC coil is If AC voltage is added to the coil, the movable iron piece will vibrate repeatedly and cannot work properly.

5. If the coil part is energized for a long time, it will cause the coil to heat up and the insulation to deteriorate, causing the solid-state relay to malfunction.

2. Solutions to some faults in solid state relay coils:

1. The simple and effective method is to replace the solid state relay.

2. The next step is to confirm the voltage of the coil to prevent the voltage supplied by the coil from being lower than the operating voltage.

3. Secondly, wiring should be carried out according to the correct polarity.

4. Finally, the solid-state relay coil should be energized for a reasonable time.