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Topic: Water/flood sensor? (Read 30906 times) previous topic - next topic

Paul_KD7HB

I have a basement with a sump pump mounted two feet below the floor in a tube.  I'm looking for a way to detect if the water level has risen above a certain level.  (Sump pump isn't working).

Seems to me water sensor get corroded over time and become unreliable.  So I think that leaves an ultrasonic sensor to measure the water level or simple float switches?

Is one better/more reliable than the other?   

Easy to make stainless steel electrodes. Go to your local bicycle repair shop and ask for two or three old wheel spokes. Find nuts to fit the metric threads. Two per spoke. Fasten your copper wire to the spokes and put in your sump tube. Clamp to the side wherever you like. Hook wire s to Arduino.

Paul

Doug101

#16
Jan 10, 2019, 02:04 am Last Edit: Jan 10, 2019, 02:11 am by Doug101
Defective float switch pictures.

Doug101

Defective float switch.

Paul_KD7HB

Defective float switch.

Can't quite see what died. Is it the aluminum cap?

Paul

Doug101

I believe so.  See the bulging at the end of red arrow?  Not exactly sure how it works.  I wonder what's in the float to trigger the when to turn on and off.


Paul_KD7HB

I believe so.  See the bulging at the end of red arrow?  Not exactly sure how it works.  I wonder what's in the float to trigger the when to turn on and off.


Those are why Dell computers and a lot of other companies were almost forced out of business. The capacitors were defective when installed on the boards and over time heated and popped their corks. That is why I NEVER buy Dell. Had the same problem with a video board in the computer driving our selective soldering machine. No replacement boards were available. But we had a bunch of new, very similar caps and swapped them in. 5+ years and no failures. Bet you could do the same with the switch.

Looks like that device has a reed switch or two and a magnet in the floater.

Paul

wildbill

Although I recommended a bilge pump detector, what I actually use in my own basement for a similar purpose is a raspberry Pi and a raindrop sensor.

It seems to me though, that what you really need is some failover in the shape of another sump pump  :)

Doug101

I could replace the cap, only problem I would have is I can not make the switch watertight again.

I am curious if replacing the cap would fix the problem.  Symptom is once pump is off until the water level rises and pump turns on.  Once water level drop, pump will not trun off. 

I'm really curious, I"m thinking they must be using something like relay logic with a two inputs with on bit of storage.

Never really thought about it but a bilge pump uses is a single SPST switch.  The lever action of the float allows the pump to turn on at height greater than wher it would turn off.  Similar to how toilet tank shut off vale's work if they are on a lever arm.

Anyone know what the logic is of a pump float?  I"m thinking it"s a latching really circuit.

Two reed magnetic switches and a relay, DPDT.  As water rises S1 closes followed by SW2.  SW1 is NC and sw2 is no.  When water is high SW2 close pulling in the relay contacts turning on the pump with contact 1.  Contact 2 is used to latch the relay with SW1 which is NC in the normal condition as the float with magnet is out of range.  As water level drops past SW2 relay is latched until float with magnet reaches SW1 which them opens interrupting current flow to relay coil.

When relay is not engaged state of SW1 doesn't matter because it is in series with the relay contact.  Only way for relay to be engaged is if SW1 is in normal state, NC and relay coil is engaged.  This only happens when float is at SW2 to and closes switch contacts and energized.

I hope I got that right.

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