How to detect the short circuit or open circuit of the solenoid valve coil

1. Short circuit or open circuit of solenoid valve of electromagnetic valve factory:
Detection method: first measure the on-off with a multimeter, the resistance value approaches zero or infinity, which means that the coil is short-circuited or open circuit. If the measured resistance is normal (probably tens of ohms), it can not be said that the coil must be good (I once measured a solenoid valve coil resistance of about 50 ohms, but the solenoid valve can not move, after replacing the coil, everything is normal ), please perform the following final test: find a small screwdriver placed near the metal rod in the coil of the solenoid valve, and then energize the solenoid valve. If it feels magnetic, the solenoid valve coil is good, otherwise it is bad. .
Treatment method: Replace the solenoid valve coil.

2. There is a problem with the plug/socket:
Electromagnetic valve factory solenoid valve failure phenomenon:
If the solenoid valve is a plug/socket, there may be problems with the metal reed of the socket (I have encountered it), the wiring on the plug (such as connecting the power cord to the grounding wire), etc. The power is sent to the coil. It is best to develop a habit: screw the fixing screw after the plug is inserted into the socket, and screw the fixing nut on the coil after the valve stem.
If the plug of the solenoid valve coil is equipped with a light-emitting diode power indicator, then the DC power supply is used to drive the solenoid valve, and the pair will be connected, otherwise the indicator will not light. In addition, do not switch the power plugs with different voltage levels of the LED power supply indication. This will cause the LED to be burned/powered (switching to a low voltage level plug) to be shorted or the LED to emit light weakly. High voltage rating plug).
If the power indicator is not provided, the solenoid coil is not polarized (not like the transistor time relay with the coil voltage being DC) and the intermediate relay with the coil voltage of the diode/resistance leakage loop connected in parallel with the coil. Most of the original small Japanese>, need to distinguish the polarity). Solenoid valve manufacturer solenoid valve treatment method: Correct wiring error, repair or replace plugs and sockets.

3, the valve core problem:
Symptom 1: When the medium pressure of the solenoid valve is normal, press the red button of the solenoid valve, the solenoid valve has no reaction (the pressure medium does not change the on-off), indicating that the spool must be bad.
Treatment method: Check if there is any problem in the medium, such as whether there is a lot of water in the compressed air (sometimes the function of the oil-water separator is not very large, especially when the pipeline design is bad, there will be a lot of compressed air flowing to the solenoid valve. Water), whether the liquid medium passed has many impurities. Then remove accumulated water or impurities from the solenoid valve and piping. If it doesn't work again, please repair it (if you have time and patience and if necessary @_@) or replace the valve plug, or simply replace the entire solenoid valve.
Fault phenomenon 2: After inspection, the coil is the original coil and the magnetic force is normal when the coil is energized, but the solenoid valve still does not work (the function of the manual button of the solenoid valve may be normal), indicating that the spool is bad.