Where do you buy float switches?

[waterlily]

I want the pump in my sump to turn off if the water level gets too low so it won't burn out. I think I need to wire in a float switch, but I can't find one anywhere. I tried Radio Shack, Home Depot, Lowes, Wal-Mart, a plumbing supply store, and a landscape and irrigation supply store. I know where I can get one online, but I'd like to find one locally. What kind of store should I be looking for?

[ross76053]

Go to www.californiareefs.com. I use one and swear by it. About $25, if I remember correctly.

Ross

[beaker020]

Grainger carries them. Perhaps try other industrial suppliers as well

[xxaquanutxx]

go to a marine store... boats need them.. you can order online @ www.tackletogo.com and get it shipped out to you next day for real cheap.. they have one that is under $20.

[BeanAnimal]

eBay

The guy on there sells all plastic float switchtes for about $6.00 each.

If you use a single float switch and no latching relay, the low water level float will cuase the pump to cycle endlesssly (untill the water finally evaporates)

When the water gets low, the pump will kick off because the float is no longer makes electrical contact. The water will drain out of your return line and cause the float to rise, the pump will kick on and fill the return line. The float will rise and kick offf the pump...and so on and so on.

You need to use 2 floats, the lower float unlatches the relay, the top float latches it. Space them an inch or two apart and you will have a great "low water" failsafe.

LEt me know if you need help on the simple latch circuit. I have a few threads on teh subject, as does H20ENG (and a few others)

Bill

[Foster]

http://www.floatswitches.net/ $6 ea

[quiksilver]

I bought a float switch off ebay from a company called Mer-Made Aquatic Kits. This is superior to the average float switch because it is battery operated and therefore there isn't more than 9v running into the float switch in your water.

I have heard horror stories of people using those $6 float switches that have failed sending 120v through their water and killing everything.

I definetly recommend this float switch and have had great success with it. It was worth the 25 bucks for me.

Good Luck.

[Foster]

I use the $6 floats sealed in PVC, and I only run 12v through them. Seems like you might hav problems with them i you dont seal them up . . .. IMO

[BeanAnimal]

Been said a hundred times, but worth the trouble I guess.

You should not put 120V to a float switch in your tank. You are asking for trouble. The $6 floats are rated for it, but why risk the chance of failure or injury. Low current DC is all you need.

You should not EVER use a switch that breaks the Neutral leg of the circuit without also breaking the hot leg. In other words don't run the neutral of a 120v circuit to the float switch to keep the "Hot" leg out of the tank. Good way to get yourself or somebody else hurt. Not to mention it violates good practice, most electrical codes and good sense. (yes I know sophisticated stage lighting at times breaks the neutral conductor without breaking the hot leg...thats a whole other can of worms).

Bill

[waterlily]

Thanks, guys. Sounds a little complicated, but I'll run your ideas by my husband. I don't want to shell out $60, but maybe this would be a safer bet:
http://www.premiumaquatics.com/thestore/prods/ULTRA-FLOATSW.html

[BeanAnimal]

1 Relays at $8
2 Floats at $6
1 12v spare wall-wart
1 cheap project enclosure

about $25 bucks for the whole project. Throw in some heatshrink tubing and extras to make it look nice, and your up to $30 Far cry from $60!

Bill

[quiksilver]

Once again, watch ebay. I got my mer-made float switch for 25.

[waterlily]

Suppose I order a float switch (looked for mer-made on ebay, couldn't find anything). I am a complete novice when it comes to anything electrical. My husband knows a bit more than I do, but he's not an expert either. Could someone provide me with easy-to-understand directions for how to wire this thing into my pump?

The instructions that came with my Dolphin DP-385 pump say that running the pump dry will damage the pump, but it also says that if the pump runs dry the unit will turn itself off and then on again when the motor cools down. Do I really need a float switch if this thing has this safety mechanism?

[beaker020]

When it comes to electricity and water: If you dont at least have a good idea of what you're doing then dont mess with it. That being said they are not that hard to put together. There have been several threads on the subject in the last few weeks.

here is the link to the mer--made float on ebay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2379305644&category=3212 This comes preassembled, just plug and play.

here is another popular one http://www.aquadevices.50megs.com/

[BeanAnimal]

The float switches that are sold by the hundreds on ebay for $6 will work just fine. Read the threads that H20ENG and myself have contributed to.

Get a basic understanding of what we are trying to do with the 2 float switches and if you still don't understand, PM me and I will walk you through the circuit step by step.

Essentially you are going to buy 2 floats, a relay and some wire. Hook it all together and power it with a 12v transformer (lthe kind that powers just about every modern device) You can get the transformer from Radio Shack or steal one from an unused piece of equipment like a cordless phone charger...etc

You will "hang" the floats in your sump. One at the lowest acceptable water level. Another about 3 inches above that level.

The idea being that the lower switch will turn off your return pump if the water drops that low. The return pump will shut off, allowing the return lines to drain back into the sump. The sump level will rise a bit because of this draining.

The circuit however will not turn the pump back on (even though the bottom float is floating again!) The return pump will not turn back on untill the water reaches the top float again. This will only happen if you refill the sump :)

Bill

[barebottoms]

If you're buying other electronics anyway:

Datasheet:
http://rocky.digikey.com/WebLib/Meder%20Electronics/Web%20Info/LS02.pdf

http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=257833&Row=263215&Site=US