Minor Problem with electrical design

[swanwick]

I built the attached wiring schematic and it seems to be working as planned (no field test yet), except for one small problem.

For the case where the pump button is in NO position which means that the Hot from the single plug is running through the fuse, through the NO on the Pump button, and into the float button....If the float button is in NO position, the float switch determines whether the double plug gets power or not. So far, all good.

When the float button is in NC position. It is supposed to just be a pass through for the HOT into the double plug. It IS doing that and the float switch has no impact on the powering of the double plug. Still all good.

Here is the odd side effect...the float button light is on even when it is in NC position. It does an odd clicking noise and flashing on/off when the float switch is closed and just solid light on when the float switch is open.

The float button light is only supposed to be powered by the NO side of the float button. Could the power be going from the NC into the double plug and then backwards through the mechanical relay and into the NO output of the float button (which powers the float button light)? If so, any recommendations for how to block that?

Thx in advance,
Swan

View attachment Visio-Brew Diagrams v6.pdf

 

[iijakii]

It sounds like you have the same issue I ran into in my diagram a bit back. https://www.homebrewtalk.com/f170/led-3-way-switch-470170/

You're having power loop back through where you jumpered stuff on that outlet and need to use a diode.

 

[swanwick]

Thx so much for the response. I don't have any experience with diodes. I noticed in your post that you soldered yours. Any options you can think of that don't require soldering?

I'm pretty novice and don't have any soldering equipment.

Thx,
Swan

 

[iijakii]

Maybe just twist it around the wire and crimp the crap out of it in a butt connector or something.

 

[swanwick]

Just tried the diode...used an epoxy rectifier diode rated 200PIV and 3amps. Said it could handle a 300a surge. Crimped it to the wire with a butt connector on both sides.

Unfortunately absolutely no change to the behaviour of the circuit. Still getting the undesirable behavior when I have the float button set to not power the float switch and bypass it to power the pump.

Behavior when supposedly not powered is the button light flashing and a clicking noise when the float switch is open. Float button light stays on (no flashing) with no clicking when the float switch is closed.

It works just right when the float button is set to on (powers the float switch). Behaviour is that it turns pump on when float switch is closed and turns it off when float switch is open.

Anybody else have an idea why this might be happening given the circuit that I originally posted? Perhaps an electrical forum that someone can suggest where people might be able to diagnose?

Thx.

 

[audiophool]

If the single plug on the right, by the mechanical relay wall wart is really a male plug, is it plugged into the wall? If so, it will supply 120v to the float button light regardless of the float button position. If, as I suspect, that plug is really a female socket and the wall wart plugs into it, then I wonder if the mechanical relay is normally closed (there may be more than one set of terminals so you can choose whether it is NC or NO. If the relay is NC and is opened when the wall wart gets power (assuming the float switch is closed) then when the float button is in the NC position, power will flow through the closed mechanical relay to light the button light. It will also send power to the single outlet, activating the mechanical relay, which will cut the current flow through the relay. This will give a click sound and the button light will go off. But when the current flow through the relay is cut, power to the single outlet will be cut off and the relay will close again, relighting the float button light and giving another relay click, and starting the cycle all over again. If the float switch is open, then the relay remains closed and the light will be steady.

This sounds to me like what you are describing, but it depends on my assumptions that the mechanical relay opens when power is applied, and that the wall wart is plugged into that single outlet. If those are wrong, ignore the confusing mess I wrote above

Bottom line, if I am correct, is that the mechanical relay needs to be wired so that the contacts are closed when power is applied, if that is an option. Otherwise, get a relay that is normally open.

Hope this helps.

 

[audiophool]

Did you ever get this figured out?