Reset button for relay switch

[Iamabug]

Ok here is my situation. I have a 12v Float Switch wired to my return pump. It goes through a DPDT relay. Pretty standard setup. The purpose of this is so that if the OVERFLOW ever stops working it will prevent my return pump from draining the sump onto the floor of my house. As it works right now when the water in the main aquarium starts to fill up to the point where the tank will overflow the switch breaks the circuit which shuts the pump off. Great, prefect.....but its not. As the water level drops in the tank it turns the pump back on. Then the water will fill and repeat the process. This is where I need to make the change. I want to add in a reset switch (momentary switch maybe) of some type that will HAVE to be reset/pushed to allow the circuit to power up again. This way I come home and can see that something went wrong with the overflow and I can fix it before starting the whole thing up again. I don't want the tank to fill drain fill drain all day until I get home. Any thoughts or help is great. I can supply a wire diagram of how its currently hooked up if needed.

Thanks
Jeff

 

[Bluejets]

Easy......use a push button as a start with one of your relay contacts(or an aux relay) as a hold-in across the start button. Your float switch then becomes a series stop switch. The latter would of course have to be normally closed during normal operation.

 

[Iamabug]

One thing I didn't mention. My experience with electronic circuits is limited, very. Think of a person who took at "Home Electronics 101" online...very basic understanding. I am just learning with this project I am on. Lots of forum lurking.

My understanding is this ( bear with me )

120v goes through relay, normally closed, powering the pump.
12v goes through float switch, which is normally open.
When float switch activates it becomes normally closed activating the 12v relay coil which makes the 120v circuit normally open, shutting down the pump.
So, I somehow need to make it so that when the float switch becomes normally open again the 12v circuit stays normally closed preventing the 120v to become normally closed again. Is this the basic idea.

1. I have a momentary NO switch. Would this work in the circuit or would I need a momentary NC switch?

2. Would this switch be in parallel or series?

3. Do I have to either buy a latching relay, or can I just wire my existing DPDT relay to make it latch?

This is the part that I am having trouble figuring out.

 

[Bluejets]

Look up standard stop start circuit on Google. .....easy

 

[Bluejets]

While your relay operation works, it is however back-to-front or commonly known as negative logic. Operation in the normal world is.... close (power up) the relay tomake the pump run. Otherwise you'll just get yourself all confused.

 

[Iamabug]

If I wire it to power the relay to run the pump, will that consistently draw current from the 12v source. I was thinking that if I wired the relay normally open it would prevent wear on the relay.

I am guessing that if I wire it normally closed then I think I can figure out the circuit. If there would be no damage to the relay then I could rewire it. This pump runs 24/7.

I did look up start stop circuits and I think I get the idea. If the relay was normally close during operation I think I can get the momentary NO switch to work.

Cheers

 

[Bluejets]

Try this..... most relays will run 24/7

 

[Iamabug]

Here is what I ended up with. Pressing the momentary switch starts the circuit. Float switch disables circuit until momentary switch is pressed.

 

[Minder]

Here is some standard stop start etc, Telemecanique wiring diagrams
See pg6 fig2, ignore the OL.
M.