why does float switch stick on?

[buffalo123]

I have a float sensor switch (magnetic type) ;occasionally get stuck on. Can't figure out why . No snails nothing notable. Yet every now and then it sticks on. I will now add another flow switch that will work in reverse to shut it off if it sticks. Should i add bigger float ? Anyone experience with them
http://www.lulusoso.com/upload/20110724/Liquid_Water_Level_Sensor_Horizontal_Float_Switch.jpg

[thegrun]

Calcium deposits will form on any float switch, so they need to be cleaned periodically. I use a 4 float switch set-up with a conductivity probe for added protection. #1 float switch is set for my intended water level. #2 is 1/2" lower than #1 and is used if #1 fails to turn on the pump (sticks in the off position). #3 is set 1/2" above the #1 float and is used if #1 fails to turn the ATO pump off. #4 is used in the ATO reservoir and will not allow the ATO pump to turn on if the water level in the reservoir is too low. I also have a maximum run time for the ATO programed into my controller to avoid an overflow. My conductivity probe will also shut off the ATO pump if the conductivity (salinity) drops too low. Lastly I have a couple of leak detectors that will also shut off the ATO pump if they detect a leak. Paranoid I know, but am I paranoid enough?

[buffalo123]

Wow you take no chances. the way to go. If it can go wrong; chances are .....

[buffalo123]

Got stuck last week the salinity went from 1.027 to 1.023. second time that happened after examining it, testing it ;I can't seem to get it to stick. But wait until i'm not home. I come home to pump running with little water in bucket.
The float switch also hooked up to a night light , whenever the pump is activated the light go on. if I see the light on I know pump is running, or close to running. (flickering light mean not enough current to activate pump but pump will run soon) . Like to try with bigger float ; maybe silicone another piece of Styrofoam to float portion.
However I also don't want to risk so will try second float to shut off ;to be safe.

[ca1ore]

By 'getting stuck' do you mean that the float is getting stuck at the highest point of the switch shaft, or that the float moves freely but the switch remains in the on position? If the former, then it just needs cleaning; if the latter then the reed switch is failing and you should replace the entire switch.

[buffalo123]

By 'getting stuck' do you mean that the float is getting stuck at the highest point of the switch shaft, or that the float moves freely but the switch remains in the on position? If the former, then it just needs cleaning; if the latter then the reed switch is failing and you should replace the entire switch.

Float is at maximum height pump stays on although it should be off. added a safety last night by adding second float switch that shut off pump once water reaches a certain height.
Float switch not used very long maybe 2 months, looks clean. Last chance for this method .

[zachts]

Are you running it thru a relay? or is it switching pump directly? Those little switches can't handle much current or the reed gets damaged or fused in the closed position pretty easy.

I wouldn't let more than about 50mA flow thru them. your light might be drawing enough current to damage the reed.

[km1das]

Also, if not running a relay you are in a lot of danger. These float switches are designed for DC and should NEVER be run with AC through them no matter how little current. Use a relay for sure and also add an outlet timer to it so that it can operate only once an hour, 10 minutes an hour may be a good start but you can mess with it. That's a good backup too.

[Triggerfish]

i tried two of those switches before running a maxi 1200 direct, both failed within a week.

[4Hummer]

Pressure Switch. No chance of it getting stuck

[buffalo123]

I disconnected them yesterday as i saw it was getting stuck again. I did not read anything saying dc only. Maybe later i make my own using a pressure switch.

[zachts]

I disconnected them yesterday as i saw it was getting stuck again. I did not read anything saying dc only. Maybe later i make my own using a pressure switch.

I'ts not that they are DC only but the higher the voltage the less current you can put thru them as higher voltage arcs easier and damages the reed (those are really cheap) rarely seen issues with them using DC and controlling a relay to switch your AC components.

Are you using a relay? If not that is most definitely why they keep getting stuck. Too much current, or rather just on the edge of being enough to permanently fuse the reed closed.

It is simply foolish to use these cheap switches in saltwater with AC current. Your just asking for bad things to happen.

[buffalo123]

I'ts not that they are DC only but the higher the voltage the less current you can put thru them as higher voltage arcs easier and damages the reed (those are really cheap) rarely seen issues with them using DC and controlling a relay to switch your AC components.

Are you using a relay? If not that is most definitely why they keep getting stuck. Too much current, or rather just on the edge of being enough to permanently fuse the reed closed.

It is simply foolish to use these cheap switches in saltwater with AC current. Your just asking for bad things to happen.

I did not use a relay. But i can see how being on the edge of full power can cause issue.

[ca1ore]

I did not use a relay. But i can see how being on the edge of full power can cause issue.

Indeed, that is why the switch is failing. Simply not designed for that; plus running full current and voltage through a sumberged switch is bad idea for self safety issues - talk about 'stray' voltage :(

I've used dozens of these 'cheap' float switches, some for over 10 years, and have had very few failures. But I always run them through a relay.

[spoon671]

Pressure Switch. No chance of it getting stuck

Got a link to the pressure switch you recommend?

[spoon671]

Awesome. Thanks...

[Triggerfish]

got an aqualifter pump to run it on. should work better.

[rwb500]

this has been discussed hundreds of times and basically any thread talking about float switches will say you need to use a relay. if you don't, you are risking a flood.

[zachts]

got an aqualifter pump to run it on. should work better.

Unless your using a sump pump float that aqualifter will only work for about a week just like your maxijet pumps, It draws just as much power ~4 watts at 120v AC, most all of the inexpensive float switches are rated for only a few hundred mA maximum. i.e. a relay coil.

[zachts]

this has been discussed hundreds of times and basically any thread talking about float switches will say you need to use a relay. if you don't, you are risking a flood.

Or being electrocuted, anyone running AC current through a cheap float off is just asking for it.......

[Triggerfish]

this guys been using his setup for couple years..
https://search.yahoo.com/search?ei=utf-8&fr=slv1-&p=youtube%20aqualifter%20pump%20ato&type=