Relay to turn power off to solenoid

[artistwantab]

Hey everyone,

I am new here and by no means an electrician.

I have a solenoid valve that needs to turn off when my ignition turns on. I also would like to turn on the solenoid with a switch when the valve is needed.

Here is my attempt to wire a relay to achieve the needed task.

Any help is greatly appreciated.

 

[artistwantab]

Am I completely off or do you guys need more information?

Just trying to get some input

 

[James]

It looks wrong to me.
you need to send 0v to coil -ve
ignition switched live to coil +ve

your output should go from com to n/c

it looks like your diagram will join 0v and 12v +ve together when the relay is not energised and will therefore be a short circuit.

 

[artistwantab]

Thank you. I really appreciate the help.

I am young (16) and trying to do this on my own for a van build I am doing. I want to learn this and I have watched as many youtube videos as I can but still not there. It seems easy to understand when they go step by step in a video.

So let me go step by step so I can learn something. Is this correct?

The solenoid is now?

BTW...if you can recommend videos or what to read I don't mind the work.

 

[artistwantab]

Thank you. I really appreciate the help.

I am young (16) and trying to do this on my own for a van build I am doing. I want to learn this and I have watched as many youtube videos as I can but still not there. It seems easy to understand when they go step by step in a video.

So let me go step by step so I can learn something. Is this correct?

The solenoid is now open?

BTW...if you can recommend videos or what to read I don't mind the work.

The Solenoid is now OPEN.

 

[Avo Mk8]

I have a solenoid valve that needs to turn off when my ignition turns on. I also would like to turn on the solenoid with a switch when the valve is needed.

Here is my attempt to wire a relay to achieve the needed task.

Hi
If the relay you are using has the internal wiring I've shown below, which I presume it does, I would say your first diagram is correct (but see update below!)

Atristwantab - an issue about the diagram is that your relay has pin numbering of one type of relay (B) but the labelling of what the contacts are, are for the other type of relay (A). Be clear which you are using!

Sorry but I find it slightly confusing that your diagram red and black wires don't go exactly to the terminals.

I think you should include an in-line fuse in the feed from the battery to the relay coil for safety reasons.

Since the solenoid will be powered with the ignition off, if your on/off switch is accidentally left 'on', the battery will go flat eventually. You'd normally want to guard against that!

Update: A source of confusion is - is it a type A relay, or a type B relay?
See diagram below. Check which you have as your diagram could be right, or wrong!
Apologies James ?

 

[James]

Well done @Avo Mk8
you were spot on at pointing out my mistake.

 

[Avo Mk8]

Well done @Avo Mk8
you were spot on at pointing out my mistake.

Actually James, I was just as 'wrong',as you!
As I've now added to my post, there are two styles of relay, A & B, and the confusion arises because type A does have a contact connection where I thought the coil normally was.
But the pin numbers on the OP's diagram are for a type B. So there is a mix-up.
Tried to clarify in my post, but not not sure I have ?

 

[artistwantab]

I may have confused you both. I wrote the NO, NC and COM as notes to myself of the relay layout without power so I wouldn't confuse myself.

What I read and watched on youTube is that without power 85 is NC. When you add power 85 becomes closed and 87 becomes NC and 85 is now NO .

I am happy to know I was close with my first diagram.

Since the solenoid will be powered with the ignition off, if your on/off switch is accidentally left 'on', the battery will go flat eventually. You'd normally want to guard against that!

The only way I know how to do that is...

Sticky Notes or timer light switch.

Is there more of an elegant way of doing it. BTW. The solenoid only uses .75 amp.

Here is the latest updated drawing.

 

[artistwantab]

Btw...thank you both for helping a noob.

 

[Avo Mk8]

I may have confused you both. I wrote the NO, NC and COM as notes to myself of the relay layout without power so I wouldn't confuse myself.

What I read and watched on youTube is that without power 85 is NC. When you add power 85 becomes closed and 87 becomes NC and 85 is now NO .

Hi
If you look at the relay image I posted, you will see that the magnetic coil that operates the contacts is wired to pin 85 and 86, and you have correctly drawn your ignition powering those.
But in your latest message above, you are referring to 85 as a contact, which is incorrect. It is normally the ground of the coil, as you have drawn.
Either you are watching a video about a differently numbered relay, the video is wrong, or you may be slightly muddled with the numbers and the naming.
The common of the switch is 30
The NO contact is 87
The NC contact is 87a
The above nomenclature is fixed by the design of the relay.
The only thing that changes when the relay operates is which circuit is closed, and which open - they just swap as you know.

In your case, unlike most applications of relays, you want to use the NC contacts, as you want activation when the ignition is off. So the switch in your circuit comprises contacts 30 and 87a

Your latest drawing is fine for the type of relay called B above, which corresponds with your circuit. If you have bought the relay already, the schematic and pin numbering is often shown on the side of the case - so worth checking they tie up with your diagram!

Incidentally, I generally find it useful to draw out the circuit I want to implement, using traditional electrical symbols, not worrying about the physical wiring and pin numbers etc. And then when I'm satisfied I have the correct 'design', I annotate things like pin numbers and wire colours second. I find I need to understand the circuit first. Just from a physical wiring diagram it can be difficult to grasp what is happening - just my thoughts - excuse the ramble!

The only way I know how to do that is...

Sticky Notes or timer light switch.

Is there more of an elegant way of doing it. BTW. The solenoid only uses .75 amp.

The only thing I can suggest is if there is a source of power that goes off only after the van is locked (my car has a supply to the dash that stays on for a while when sitting in the car with the ignition off, but after I exit and it's locked, that supply goes off)! Unless of course you want this thing to be operating while the van is locked ?

Here is the latest updated drawing.

View attachment 91818

That looks good to me
Good luck with the project ?

 

[artistwantab]

Hi
If you look at the relay image I posted, you will see that the magnetic coil that operates the contacts is wired to pin 85 and 86, and you have correctly drawn your ignition powering those.
But in your latest message above, you are referring to 85 as a contact, which is incorrect. It is normally the ground of the coil, as you have drawn.
Either you are watching a video about a differently numbered relay, the video is wrong, or you may be slightly muddled with the numbers and the naming.
The common of the switch is 30
The NO contact is 87
The NC contact is 87a
The above nomenclature is fixed by the design of the relay.
The only thing that changes when the relay operates is which circuit is closed, and which open - they just swap as you know.

In your case, unlike most applications of relays, you want to use the NC contacts, as you want activation when the ignition is off. So the switch in your circuit comprises contacts 30 and 87a

Your latest drawing is fine for the type of relay called B above, which corresponds with your circuit. If you have bought the relay already, the schematic and pin numbering is often shown on the side of the case - so worth checking they tie up with your diagram!

Incidentally, I generally find it useful to draw out the circuit I want to implement, using traditional electrical symbols, not worrying about the physical wiring and pin numbers etc. And then when I'm satisfied I have the correct 'design', I annotate things like pin numbers and wire colours second. I find I need to understand the circuit first. Just from a physical wiring diagram it can be difficult to grasp what is happening - just my thoughts - excuse the ramble!

The only thing I can suggest is if there is a source of power that goes off only after the van is locked (my car has a supply to the dash that stays on for a while when sitting in the car with the ignition off, but after I exit and it's locked, that supply goes off)! Unless of course you want this thing to be operating while the van is locked ?

That looks good to me
Good luck with the project ?

Thank you so much. Somewhere I did have it mixed up.

Glad I was in the right direction and thank you both again for the help. Be well.

 

[Dseelye]

Thank you so much. Somewhere I did have it mixed up.

Glad I was in the right direction and thank you both again for the help. Be well.

Something to also keep in mind. Is that a relay shouldn't switch more than it's intended load. check the solenoid wattage compared to the relay rating. BTW the starter would me wired similarly with the battery voltage on the Common of the relay and the starter on the NO of the relay, so there is probably already a relay present that has the NC not used.

 

[artistwantab]

Something to also keep in mind. Is that a relay shouldn't switch more than it's intended load. check the solenoid wattage compared to the relay rating. BTW the starter would me wired similarly with the battery voltage on the Common of the relay and the starter on the NO of the relay, so there is probably already a relay present that has the NC not used.

Max Swiching Current 40a
Max Switching Voltage 30 VDC
Max Switching Power 560

The solenoid is 12v .75 amps

I don't want to fuss with the OEM wiring or relays to much.

Its a can-bus system that is touchy from reading I have done on the sprinter forums.

Intend to wire it after the starter relay on the relay outlet wire.

Is this what you asking.

 

[Dseelye]

Well it's possible that the starter relay already has a common, Normally open, and a Normally closed terminal. If it dose have all three and saying that the battery 12 v is on the common you would have two outputs on the starter relay. The Normally open output would already be wired to send 12v to the starter upon ignition. So the Normally closed in this case could be used to send 12v when not using the starter. However the starter relay might only have a common and normally open position, so you would use your second schematic. Keep in mind also that the battery is not always on the common in the scenario I gave for the starter. For instance the 12v from the battery is on the NO and the Common is going to the starter.

 

[artistwantab]

Thanks. Since I am new to this I am not going to fuss with the existing relays.

The sprinters electrical from what I have read is a bit touchy so don't want to complicate things. Thank you though for the information. Another thing to learn.

 

[Simon47]

The solenoid is 12v .75 amps

Over 4 days, which is nearly 100 hours, that's 75 AHr - your battery will be too flat to start the vehicle (or if it isn't it will be by the time a week is up), and if you leave it going for longer then you'll damage the battery as well. Not to mention the hassle of sorting things out (e.g. re-coding the radio) when they've been powered off.

I'm curious what is it you need to be powered only with the key off, and why you can't do it the other way around - powered with the key on.

 

[artistwantab]

Over 4 days, which is nearly 100 hours, that's 75 AHr - your battery will be too flat to start the vehicle (or if it isn't it will be by the time a week is up), and if you leave it going for longer then you'll damage the battery as well. Not to mention the hassle of sorting things out (e.g. re-coding the radio) when they've been powered off.

I'm curious what is it you need to be powered only with the key off, and why you can't do it the other way around - powered with the key on.

Would not function as needed to only be on when the ignition is on.

 

[James]

What type of solenoid is it?
i.e. valve, lock, actuator?