# 12v Water Solenoids

**URL:** <https://forum.core-electronics.com.au/t/12v-water-solenoids/17535>\
**Category:** Support\
**Created:** [10 July 2023 05:26 UTC](https://forum.core-electronics.com.au/t/12v-water-solenoids/17535 "2023-07-10T05:26:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Lachlan251739](https://avatars.discourse-cdn.com/v4/letter/l/a587f6/32.png) [@Lachlan251739](https://forum.core-electronics.com.au/u/Lachlan251739)\
**Post date:** [10 July 2023 05:26 UTC](https://forum.core-electronics.com.au/t/12v-water-solenoids/17535/1 "2023-07-10T05:26:38Z")

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There are 2 similar water solenoids on your website. Neither indicate the polarity of their electrical connections. Could you please advise how they should be wired? Thanks

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**Author:** ![Trent5487676](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/trent5487676/32/4583_2.png) [@Trent5487676](https://forum.core-electronics.com.au/u/Trent5487676)\
**Post date:** [10 July 2023 05:50 UTC](https://forum.core-electronics.com.au/t/12v-water-solenoids/17535/2 "2023-07-10T05:50:47Z")

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Hi Lachlan,

I’ve noticed most of the solenoids will state they need a DC voltage to actuate them but don’t include a polarity. I’ve just tested two we had on the shelf in the warehouse with a laboratory power supply and it seems they are happy to actuate with either polarity.  
I’m not sure if there is internal circuitry at play here, or a mechanical solution to make sure the solenoid deflecting in either direction gives the same output but from an end user perspective you’ll just need to make sure your power supply has enough current to drive them.

If you’re curious the two I tested were these:

> **[12V Solenoid Valve - 3/4" BSP](https://core-electronics.com.au/12v-solenoid-valve-3-4.html)**
>
> Have you ever wanted to control the flow of a liquid using your computer or microcontroller, but didn’t know how? Well, here’s how: The 12V solenoid controlled fluid valve. Simply connect a fluid source to the ¾" threaded inlet and it will interrupt...

> **[Brass Liquid Solenoid Valve - 12V - 1/2 NPS](https://core-electronics.com.au/brass-liquid-solenoid-valve-12v-1-2-npt.html)**
>
> Control the flow of fluid using the flow of electrons! This liquid valve would make a great addition to your robotic gardening, aquarium, or pool project. There...

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**Author:** ![Robert93820](https://avatars.discourse-cdn.com/v4/letter/r/ac91a4/32.png) [@Robert93820](https://forum.core-electronics.com.au/u/Robert93820)\
**Post date:** [10 July 2023 10:18 UTC](https://forum.core-electronics.com.au/t/12v-water-solenoids/17535/3 "2023-07-10T10:18:29Z")

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Hi All  
Solenoids are usually just an electro magnet which attracts an “armature” into the magnetic field. Thus are not polarity sensitive and does not matter which way around the field is. They usually have some sort of spring return to send the armature back to its un powered position.

There are some which require the field to be one way to attract the armature and the other way to repel it. These ARE polarity sensitive as the field is reversed simply by reversing the connection and thus current direction. In this case the armature or moving part has to be a magnet with North and South pole.

There are actually others which are “Rotary” solenoids. An example is a “Ledex” rotary switch where a voltage is applied and the switch steps around until the voltage is removed when an open circuit is found as dictated by a remote “master” switch.  
Cheers Bob