Auto top off float switch.

[greenstarman]

I am confused on reading this. It says maximum switching voltage is 220vac. But when you check out the design on the same site for auto top off plans they use a 9 volt DC transformer but Melev uses it in series with 120vac. I take it that float switch is capable of handling both DC and AC?

When the relay is added the 9 volts becomes the control voltage for the coil on the relay. So if you don't care about voltage spikes from the pump just wire it directly with 120vac?

http://www.aquahub.com/store/ifloatfloatswitch.html

 

[kgross]

The problem is that the voltage spikes from the pump will cause the switch to fail sooner, normally causing the switch to weld itself closed so your top off does not shut off. If you only run the 9 volt low current through the switch it will last a lot longer.

Kim

 

[greenstarman]

Still doesn't answer my question.... This switch is rated for AC and or DC currents?

 

[shouldabenacowboy]

You are correct. This switch can handle both AC and DC. I have mine (exact switches as you have linked to) running on 12vdc control and it works perfect. I ran 2 of these switches in series as a fail safe just incase one of them did "weld" shut.

Hope that helps

SBC

 

[1package]

I use the aqua hub floatswitches, now with an AC relay although I do not know if it is necessary. With or without a relay, you almost need a timer. I burned up two reed switches/floatswitches quickly initially. The problem was the water level would drop to that almost yes almost not level and I would get the on/off, on/off, on/offs all the time, the float switch did not last long. My solution, I added a relay but I also used one of my timers and set it up so that the power to the floatswitch was only on 4 times per day for about 10 minutes. That way I was filling a larger volume of water for longer periods of time as opposed to the short constant on/off.

 

[greenstarman]

Did you burn them up because they were directly wired to AC? I couldn't grasp that from your message, Sorry.

Thanks for the answers....

 

[DaveBrader]

I have been using the same float switches for almost three years now and have never had one fail. I use mine with a relay, 12v DC, from the switch to the relay. When I made my top off system, I used two switches also for back up. The second switch has never even cycled because the water lever has never reached it in the sump, so it is brand new still LOL

 

[rdknjsr599]

Ultimately it is what the float switch is being used to turn on that is deciding factor as to how long it will last vs. the voltage that is used. If your switching something that is an inductive load (i.e. solenoid etc.) that has a high inrush current, the switch won't last very long. I personally would use an float switch to drive an interposing relay as mentioned above in some of the other replys, and use 12VDC (allot less lethal should something go wrong).

 

[DaveBrader]

Absolutely they should be used with a 12v DC relay. Why put household current into your sump when for less than 25 bucks you can add a 12v DC power supply and relay and only put 12v DC into your sump.

I have been shocked by household current in my sump once, that was all it took for me...

My Topoff system runs a small 50gph Rio Pump and keeps my sump level within 1/8 of an inch of level at all times. The pump comes on for less than a minute when the float switch tells it the sump is low. The amount of water it pumps is nothing at any one time, but the system replaces 4 gallons a day of evaporated water.

 

[greenstarman]

Geez.... I am lucky to have a 1/2 a gallon a day...

 

[UH_OH_5_OH]

Wasn't there an Auto Top Off Thread here somewhere with pictures from Rick s...?

 

[goreefer]

Switches do not care if the current is AC or DC, they simply are switches.
I use float switches from Grainger’s, paid about $12. They are commonly used for evaporative pumps on home and commercial A/C units. They look a little more substantial than some of the smaller float switches that I have seen on the internet, but you can never tell from looks only. Usage of lower voltage will increase their life. Have you ever seen a 9volt battery spark? If you use a transformer you will not need high amperage to trigger the switch, so look at the output of some of those plug in the outlet transformers that are lying in the junk drawer. They will work fine.