Auto Top Off Help!

[ChrisOaty]

Hi guys, just finished soldering up my float switch to an extension cord for my fill pump. I'm using a 5 gallon bucket in my cabinet. Testing the switch with a light bulb I ran into a problem. The light was off when the float was up (so far, so good), and turned on when I let it drop to within a centimeter of the bottom (good deal). When I pulled the float back up the shaft, the light bulb stayed on (uhhh...). Perhaps I have no idea what I am doing, or how this thing works, but have i done this wrong? Is my float switch bunk? Help please.

 

[DaveK]

Float switches should usually be operated at low voltages and then use a relay to operate the house current to your pump. Yea, I know, many float switches are rated for house current voltages, but they often don't work out too good if you do that.

Most likely the contacts on the float switch arced together. You might get lucky and be able to get them apart by tapping on the float switch or moving the magnet up and down a few times.

 

[Reefer85]

Ok, i know this is $80 (which seems steep to me for what it is), and you seem to be way more comfortable with DIY than I am, BUT, this is what I use and they rock... every once in a while the suction cup will fall off, but it's usually when I'm messing around in the sump and it's directly under the 250 watt MH so it probably gets dried out... but anyway, here's the link, in case you can't sort out what you have and are looking for options...

Amazon.com: Ultralife Float Switch: Pet Supplies

Cheers...

 

[ChrisOaty]

Thanks Dave! That was an assumption of mine, I'm glad you came to the same conclusion. The leads are fairly thin so I questioned whether they were supposed to be placed within the house circuit. I'm super weary of using it now. If it malfunctions, I'll have water on my carpet and my salinity would drop to dangerous levels.

Good suggestion Reefer85, but it is a little much for my budget. Thank you any way, and I'm happy it's working out for you.

Any way to make this work? I'm comfortable with DIY, but as mentioned above, budget-minded.

 

[DaveK]

An additional thing you can do is to use 2 float switches in series. Mount them so one is about an inch higher than the other.

That way you have a fail safe if the lower one sticks on. If you see the water level higher, you know the lower switch has failed in the on position.

 

[BigAl07]

I think you may need to re-visit running this without a relay. You want to use LOW voltage so if something does happen you're not electrifying the water with house voltage. It adds some degree of complexity to the build but it's not an option IMHO in this situation. Be careful

 

[aprime11b]

Im trying to figure out this same thing