Why aren’t the wires of a 24V solenoid valve distinguished as positive or negative?
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A 24V power supply is a direct current supply with positive and negative poles. However, in practice, when connecting a 24V solenoid valve on-site, there is no need to distinguish between positive and negative; the valve can still function properly regardless of how it is connected. Why is that?
There is no distinction between positive and negative poles in the wiring of solenoid valves; it doesn’t matter how they are connected. When power is applied, a coil is located inside the square chamber, and the power causes an iron rod to be attracted in, thereby enabling conduction! Or think of the solenoid valve as an automatic switch; that’s a good way to understand it
I’d like to remind the original poster that some of the wiring terminals for the solenoid coils we use now are marked with the polarities “+” and “–”; these cannot be connected in reverse. A diode is connected in series within the coil circuit, so it’s possible to use a multimeter to check before making the connections. In the forward direction, the coil resistance can be measured, while in the reverse direction the resistance will be infinite. If both the positive and negative vectors have resistance, there is no need to consider positive or negative when making the connections.
Simple coils do not require a distinction between positive and negative poles. The light bulbs in your home also don’t have positive and negative poles.
The excitation coil of a solenoid valve has no positive or negative poles, so the wiring also does not have distinct positive or negative connections.
When an electric current flows through a coil, magnetic force is generated according to the principle of electromagnetic induction; the direction of the current determines the directions of the N and S poles； However, for the armature, both the N pole and the S pole exert an attractive force on it; therefore, there is no need to consider the positive or negative direction when making the connections here.
Reply to 4# wangjh1975: Thank you, senior, for suggesting such a good method; I’ll give it a try as well.
DC solenoid valves should have positive and negative poles, while AC ones do not need to
Reply to 9# heartoking: What is a DC solenoid valve? What is a AC solenoid valve?
Reply 10# *ao1988711: If the solenoid valve has high power consumption, there is no need to distinguish between positive and negative poles; however, for low power consumption, it is necessary to differentiate between them, otherwise it will not work