How to use a multimeter to test a solenoid valve? Are the solenoid valves divided into positive and negative poles?

How to use a multimeter to test a solenoid valve


1. Prepare the multimeter and ensure that the multimeter can be used normally;


2. Insert its two test leads into the COM port and V port;


3. Select the DC voltage range of the multimeter, usually below 12v;


4. Place the two test leads on the solenoid valve power interface to see if the voltage of the multimeter matches the supply voltage value. If so, it means there is no problem with the power supply and further testing is required.






The inspection and judgment methods of solenoid valves can be roughly divided into three types:


1. Static inspection of solenoid valve
Static inspection means to measure the resistance value of the solenoid valve when the ignition switch is OFF, connect the tip of the multimeter to the pin of the solenoid valve, and observe the resistance value displayed on the instrument screen. If it is greater than the rated value, it means that the solenoid valve coil is aging;if it is lower The rated value indicates a short circuit between turns of the coil;if it is infinite, it indicates an open circuit of the solenoid valve coil. These conditions indicate that the solenoid valve has failed and must be replaced.

2. Dynamic inspection of solenoid valve
Dynamic inspection refers to simulating the actual working process of the solenoid valve, replacing the oil pressure with a certain air pressure, and checking whether the valve core of the solenoid valve moves smoothly and whether the sealing is good through continuous artificial stimulation of the solenoid valve.​

Use an air gun to apply a certain amount of air pressure to the working oil hole of the solenoid valve through the cone-shaped rubber head. Press the control switch to repeatedly turn the solenoid valve on and off. Observe the changes in the air flow at the drain port. If the air flow always exists, it means that the solenoid valve is on and off. Valve seal is poor.

If there is no air flow all the time, it means that the solenoid valve is blocked and stuck;if the air flow is on and off out of specification, it means that the solenoid valve is occasionally stuck;if the air flow changes with the action of the solenoid valve, it means that the solenoid valve is normal.

The inspection results of the first three indicate that the interior of the solenoid valve has been worn and must be completely replaced during the maintenance process.

3. Thermal check of solenoid valve
As the name suggests, the thermal check refers to simulating the set temperature that the automatic transmission can reach during normal operation, using a hot air blower or other oil, electricity and other heating equipment to artificially heat the solenoid valve to its normal operating temperature, and then Carry out resistance and dynamic pressure tests. If the inspection results are normal, it means there is no problem with the solenoid valve;if it behaves abnormally, it must be replaced without mercy.





Is the solenoid valve divided into positive and negative poles?


Solenoid valves generally have no positive and negative characteristics, but very few solenoid valves may have diodes inside, which have positive and negative characteristics. The solenoid valve is originally a coil that generates magnetic force through electricity to drive the valve stem to move, so the coil only needs to be energized. That’s it. Solenoid valve is an industrial equipment controlled by electromagnetism. It is a basic component of automation used to control fluids. It is an actuator and is not limited to hydraulic and pneumatic.

The wiring of solenoid valve products is relatively simple. Generally, the power cord of a solenoid valve has three wires: ground, positive and negative. If it is AC, the positive and negative poles of the wiring do not need to be considered. If it is DC, you need to pay attention to the positive and negative poles, and Make sure the voltages are the same.





The above is an introduction to how to use a multimeter to test a solenoid valve. Are the solenoid valves divided into positive and negative poles? If you want to know more relevant information, please log in to www.diancifa.cc of Sunway Pneumatics.