water detection relay?

[Rascally]

Hello everyone,

What is an electrical relay that could break the 12v circuit feeding a 6amp seawater pump?

Our toilet's seawater pump was triggered ON by an electrical fault; we soon had the aft cabin head and bilge full of seawater, and if the Admiral hadn't been aboard, we would have drained our house bank while the toilet pumped water into the boat while the bilge pumped it out. She found the ordeal a little stressful, considering she was alone at the time, and is not an electrician.

The Admiral suggests there's likely a $50 solution that could prevent a similar scenario.

So yes, we've addressed the electrical fault (water leaking under the vanity countertop and dripping onto the toilet's water switch), but the Admiral wants something to cut power to the 12v pump if water is detected in the bilge.

What is the reliable but simple solution?

Thanks for reading this far!

Randall

[rslifkin]

There are a few ways you could do it. Either a timer circuit where if the pump runs longer than X time it trips and requires a manual reset. Or a normally closed relay triggered off a float in the bilge (or the bilge pump circuit) so bilge water will cut power to the pump.



Or the simple answer: turn off the power to things like toilet pumps when leaving the boat unattended.

[Rascally]

Originally Posted by rslifkin

There are a few ways you could do it. Either a timer circuit where if the pump runs longer than X time it trips and requires a manual reset. Or a normally closed relay triggered off a float in the bilge (or the bilge pump circuit) so bilge water will cut power to the pump.

Or the simple answer: turn off the power to things like toilet pumps when leaving the boat unattended.

So, the best answer is to flip off the breakers to pumps when we leave the vessel. That said, we live aboard, and we're going to forget sometimes. I think a simple solution will be very affordable.

Now, our bilge runs occasionally for other reasons, like condensate runoff, so I don't want to tie this to the boat's main bilge pump. Rather, each cabin has a head, and if there was to be overflow of the head compartment, the water overflows into each cabin. I'd like to detect water at that point, possibly using a water detection sensor, and have that sensor trigger a relay that cuts power that supplies the pump. I imagine we'd interrupt power after the toilet flush switch. This solution could be installed in each head, as a stand alone solution that is just there to kill the water pump if there is water flowing from the head.

I think I need a suitable water sensor and a relay - but I don't know what devices to search for. 🤪

[rslifkin]

Originally Posted by Rascally

So, the best answer is to flip off the breakers to pumps when we leave the vessel. That said, we live aboard, and we're going to forget sometimes. I think a simple solution will be very affordable.

Now, our bilge runs occasionally for other reasons, like condensate runoff, so I don't want to tie this to the boat's main bilge pump. Rather, each cabin has a head, and if there was to be overflow of the head compartment, the water overflows into each cabin. I'd like to detect water at that point, possibly using a water detection sensor, and have that sensor trigger a relay that cuts power that supplies the pump. I imagine we'd interrupt power after the toilet flush switch. This solution could be installed in each head, as a stand alone solution that is just there to kill the water pump if there is water flowing from the head.

I think I need a suitable water sensor and a relay - but I don't know what devices to search for. 🤪

Any 5 pin relay of suitable amperage will do. You wire the pump through the normally closed contacts so when the relay gets power it disconnects the pump power. Finding a water switch that'll work in the location, water level, etc. you want will be the slightly harder part. Basement water detection sensors might be close to what you want.

[Rascally]

Originally Posted by rslifkin

Any 5 pin relay of suitable amperage will do. You wire the pump through the normally closed contacts so when the relay gets power it disconnects the pump power. Finding a water switch that'll work in the location, water level, etc. you want will be the slightly harder part. Basement water detection sensors might be close to what you want.

Thanks! This type of relay? https://www.amazon.ca/Ehdis®-Motor-R...5&sr=8-18&th=1

For a water switch, there is a spot where water collects in the cabin bilge, so this might work:
https://www.amazon.ca/gp/product/B0B...NLOIM50D&psc=1

Your thoughts?

[wholybee]

I would use a 5-minute timer relay, that you activate when you enter the head, that will allow anything in there to work for 5 minutes, and then it would need to be reset.

I think a water detection relay (like a float switch) would be a common point of failure that you would be too often servicing.

[rslifkin]

Originally Posted by Rascally

Thanks! This type of relay? https://www.amazon.ca/Ehdis®-Motor-R...5&sr=8-18&th=1

For a water switch, there is a spot where water collects in the cabin bilge, so this might work:
https://www.amazon.ca/gp/product/B0B...NLOIM50D&psc=1

Your thoughts?

That's exactly what I was thinking for a relay.

[Bill O]

Originally Posted by rslifkin

Or the simple answer: turn off the power to things like toilet pumps when leaving the boat unattended.

^^^

[Rascally]

Originally Posted by wholybee

I would use a 5-minute timer relay, that you activate when you enter the head, that will allow anything in there to work for 5 minutes, and then it would need to be reset.

I think a water detection relay (like a float switch) would be a common point of failure that you would be too often servicing.

OKAY! Now that is a great idea! 😊

The timer button could be in the head, so the user would always have access to the electric flush when needed, but normally it's disconnected.

Thank you! 👍

I'm now searching for a quality marine grade timer relay! 😜
(wouldn't want a cheap unit that fails, as it would be normally disconnected)

[Rascally]

Originally Posted by wholybee

I would use a 5-minute timer relay, that you activate when you enter the head, that will allow anything in there to work for 5 minutes, and then it would need to be reset.

I think a water detection relay (like a float switch) would be a common point of failure that you would be too often servicing.

So, I can't find it, but I'm sure it exists.

I just don't know where to browse, or the correct name to search with.

I think I need a waterproof timer switch that can wall-mount in the head, with a 5-minute (or programmable) timer. eg. Activating the switch closes the circuit, and after the timer expires the circuit opens.

Do you know where I could buy this animal? 🤪

[brazenarticle]

Take a look at the Shelly UL1 https://usa.shelly.cloud/ul-certified-relays/
I have one set on my water pressure pump so it turns off the circuit 20 minutes after I turn it on. The purpose is to save water and battery if a faucet is accidentally left open or there is a leak. Just turn the switch off then on again to get another 20 minutes in this case.
These are 12 volt 15 amp relays with wifi so you can set them up from phone, tablet or computer. No need for internet or even a network on the boat ( unless you want to control the toilet from afar via internet).
The Shelly 1 could be set up with a push button switch, wired into a light or panel switch or some other options, then set the timing you want from the app or a web browser.
These are handy since they work well with 12 or 24 volt systems, they're cheap and seem robust. Not waterproof though. I have several mounted behind various panels and under shelves for different jobs aboard.
https://pysselilivet.blogspot.com/search?q=shelly and http://https://boathackers.com
have articles about various devices, might need to search Shelly on each page.

[AKA-None]

Any thoughts on a switch that must be turned on to activate the pump

Then it’s simply off all the time except when you want water?

[pesarsten]

what about a simple mechanical timer switch?

https://www.amazon.com/BN-LINK-60-Mi...841710&sr=8-15

[OldGreyB]

Originally Posted by Rascally

So, I can't find it, but I'm sure it exists.

I just don't know where to browse, or the correct name to search with.

I think I need a waterproof timer switch that can wall-mount in the head, with a 5-minute (or programmable) timer. eg. Activating the switch closes the circuit, and after the timer expires the circuit opens.

Do you know where I could buy this animal? 🤪

You don't need a waterproof timer. Just a suitable momentary pushbutton on the wall, and a timer relay c/w base located in a normally dry area. See attached PDF's with appropriate Hella timer, with contacts rated for your stated application. These are reliable units. Google search by brand / model for local retailer in your area. Do ensure you buy the matching plugin base for the relay.

[Rascally]

Originally Posted by OldGreyB

You don't need a waterproof timer. Just a suitable momentary pushbutton on the wall, and a timer relay c/w base located in a normally dry area. See attached PDF's with appropriate Hella timer, with contacts rated for your stated application. These are reliable units. Google search by brand / model for local retailer in your area. Do ensure you buy the matching plugin base for the relay.

Wow, this is fantastic! Thank you!

You created a sketch just for this? I owe you a few beer!

Attached is a PDF of a momentary switch, hopefully suitable for the relay you've suggested? I'd like to install a switch like this beside the toilet's Flush switch. Thus, once the relay enables power "on" the toilet's flush switch can power the seawater pump.

This switch is good?

Thanks so much!

Randall