DC Module Float Switch

[DylanF1]

I would like to connect one float switch to two emergency float outlets on the Lighting and DC Module so that it will cut power to two different solenoid valves at the same time causing them to return to their normally closed position if water gets too high in the sump. I had a flooding situation last night where a pump turned on for some unknown/unexpected reason and dumped 15 gallons of saltwater in the aquarium causing the sump to overflow. This would have prevented it if it will work as planned. Please let me know if y'all see any issues with this or have a better idea/solution.

And just for the knowledge, if this is acceptable to do on two emergency float outlets, could it also be used on 3, 4, 5, and all 6? depending on the scenario....

 

[GarrickG]

Good question. I like this idea. The float-switch would need to be mounted so that it's closed at normal level and open at high water. The switch and wiring would need to be able to handle the load of all the devices...

*As an aside, in my sump, I've mounted a manual float-valve at the end of the ATO line in case the solenoid sticks. Maybe that could help with your saltwater reservoir? (I'm assuming this is an auto water change arrangement..?)

 

[DylanF1]

Good question. I like this idea. The float-switch would need to be mounted so that it's closed at normal level and open at high water. The switch and wiring would need to be able to handle the load of all the devices...

*As an aside, in my sump, I've mounted a manual float-valve at the end of the ATO line in case the solenoid sticks. Maybe that could help with your saltwater reservoir? (I'm assuming this is an auto water change arrangement..?)

Thats one thing I wasn't sure of, would the float receive the full current of the two solenoid valves? It sounds like it would. I'm using the floats from the Robo-Tank website and these solenoids from Amazon. It looks like the load wouldn't be an issue for the float.

Floats = 220volts/0.5amps = 110watts

Solenoid Valves = 5.5watts @ 12 volts x 2 valves = 11watts

Yes, it is an ATO and AWC setup that uses the same float switch to control the water level/volume in the sump. Unfortunately, the way my system is currently setup I have the freshwater and saltwater outlets dumping into the overflow in the display tank. This puts them high enough in elevation, relative to the storage tanks, that the water cannot be pushed into the display tank by head pressure. If they are in the sump, the head pressure pushes the water into the sump. It could probably be redone with a float valve and solenoids to prevent that, but the two lines would need to wye into one float valve (to maintain the same level all the time, ATO vs. AWC) and use check valves so when a pump comes on it would not back flow into the other line/solenoid. That is an option I will ponder on. I'm not sure which option would be more reliable although the float valve would add a third control on water flow if the pumps and/or solenoid's fail. The only downside would be the head pressure is now a factor.

 

[GarrickG]

I like your solution. I've not tried it. I assume those float-switch ports interrupt ground and not the controlled source side of the circuit.

If putting them in series with a float switch isn't possible, could you use separate float switches? You'd need like 3 of 'em. One to control your ATO/AWC water level. Two more mounted a bit higher as high water level kill switches on the float switch ports...

 

[Rob F]

I would like to connect one float switch to two emergency float outlets on the Lighting and DC Module so that it will cut power to two different solenoid valves at the same time causing them to return to their normally closed position if water gets too high in the sump. I had a flooding situation last night where a pump turned on for some unknown/unexpected reason and dumped 15 gallons of saltwater in the aquarium causing the sump to overflow. This would have prevented it if it will work as planned. Please let me know if y'all see any issues with this or have a better idea/solution.

And just for the knowledge, if this is acceptable to do on two emergency float outlets, could it also be used on 3, 4, 5, and all 6? depending on the scenario....

View attachment 808

Sorry to hear that, did this happen due to the software? What are you using? Did you look in the log to see if an answer is there?

The backup ports simply cut the signal from the Pi GPIO to the circuit so no current runs through the switch.

It's not recommended connecting the same float to multiple backup ports, if one GPIO is HIGH and the other is LOW it can damage the GPIO as it'll be trying to force the LOW GPIO HIGH. If both GPIO's were HIGH or LOW simultaneously in theory it should be ok but there's a good chance at some point that wouldn't happen. So best not to do that, use multiple float switches instead, one on each backup port.

It is possible to connect multiple floats in series or parallel to a single backup port, in series 2 or more floats would all need to be set closed or in parallel one of many would floats would need to be set closed but yeah that's not what you want.

 

[DylanF1]

Sorry to hear that, did this happen due to the software? What are you using? Did you look in the log to see if an answer is there?

The backup ports simply cut the signal from the Pi GPIO to the circuit so no current runs through the switch.

It's not recommended connecting the same float to multiple backup ports, if one GPIO is HIGH and the other is LOW it can damage the GPIO as it'll be trying to force the LOW GPIO HIGH. If both GPIO's were HIGH or LOW simultaneously in theory it should be ok but there's a good chance at some point that wouldn't happen. So best not to do that, use multiple float switches instead, one on each backup port.

It is possible to connect multiple floats in series or parallel to a single backup port, in series 2 or more floats would all need to be set closed or in parallel one of many would floats would need to be set closed but yeah that's not what you want.

I’m using reef-pi, I believe it was a software issue. I actually have a post over on Humble about it. I know how to watch the journal but was unaware that it logs the data somewhere. How do you access the log?

Great, thanks for the update, I’ll stick with separate floats.

The idea of putting them in series would add redundancy to the emergency cutoff in case one of the floats failed closed. How would parallel floats be beneficial? I have done the floats in series in the past with other diy ATO’s.

 

[Rob F]

I’m using reef-pi, I believe it was a software issue. I actually have a post over on Humble about it. I know how to watch the journal but was unaware that it logs the data somewhere. How do you access the log?

Great, thanks for the update, I’ll stick with separate floats.

The idea of putting them in series would add redundancy to the emergency cutoff in case one of the floats failed closed. How would parallel floats be beneficial? I have done the floats in series in the past with other diy ATO’s.

I think the journal is all you have for the logs.

In parallel you would be adding redundancy to on, if one fails open the other will close it. Probably not useful for most but I'm sure there some use cases.

 

[wizzlebippi]

Why not an analog solution? A dual relay module with the power and trigger pins wired together and set to normally open. Power/trigger the relays through the float switch, and when the float switch opens (high water), the relays are depowered and toggled open which would open both solenoid circuits. Two independent circuits so you're not damaging GPIO or putting large amounts of power through the float switch and one 5V circuit to operate the relays.

I'm personally doing this to ensure my UV sterilizer and heater are not running when the sump lift pump is off.