Float switch

[25yearslater]

Here is a question. When wiring a bilge pump float switch it is customary to break the 12V + wire and bridge with your switch. In several industrial applications breaking the 0 Volt is the prefered method. It saves on relay contacts as no arcing occurs. Since the Rule float switch seems to be a problematic switch as to reliability I propose breaking the 0 Volt and bridging with the switch providing this doesn't violate any marine rules. Thoughts? Thanks.

 

[Bluesharp]

If you break the ground wire, then the auto-manual-off switch on your panel will not work in the manual position. If you review a wiring diagram, you will see that the switch goes on the Plus side of the circuit.

 

[Maine Sail]

For marine applications you break only the hot....

Also don't confuse AC and DC as everything on your boat is switched hot... The problems with the Rule float switches is that they are now a "mechanical" switch and no longer contain the very reliable mercury ball.... There are FAR better pump switches out there and the Rule's would be my absolute last choice....

I use the See Water Oil Smart Pump switch by SEE Water Inc. You need to special order them direct from the manufacturer, and they are not cheap, but it has proven to be the most reliable bilge switch I have ever used. Heck the switch cost more than my bilge pump... They also WILL NOT pump oil out, which is a safety feature....

Oil Smart Pump Switch


EDIT: This switch has recently been discontinued (glad I bought a spare). They no longer make a marine switch because no one wanted to pay for the technology. Sad really...

Alternatives would be the Water Witch or Ultra Safety Systems switch. I have had good luck with the Water Witch and often install them because Hamilton Marine has them in stock....

 

[kloudie1]

Maine.. Have you measured the standby current of the switch? I see they post a number of 0.004 ampere but they don't specify a voltage .. I was wondering what it actually draws on 12V..??

 

[Maine Sail]

Maine.. Have you measured the standby current of the switch? I see they post a number of 0.004 ampere but they don't specify a voltage .. I was wondering what it actually draws on 12V..??

I have measured my 12V switch at 0.002A. Of course this is FAR less than what a STUCK crappy switch like a Rule will ever draw when stuck on killing a battery bank.... Any boat needs to be set up to handle some mA draws. Solar controllers, ACR's, Echo Chargers, Stereo's LPG detectors, battery monitors etc. etc. all draw some current and this should be accounted for in the system design..

Me, I'll take a far more reliable switch over cheap junk any day of the week. I replace more failed Rule, and other brands, float switches than just about anything else on boats.. IMHO they are not worth the packaging they ship in..

 

[kloudie1]

I definitely agree, Maine !.. I have a variable speed water pump that draws almost nothing at rest.. and I was wondering how much this switch draws.. My old Rule mercury switch was installed over 20 years ago and still works fine, but one day I'll need a replacement and I think a good electronic one is the ticket. IMHO, the mechanical ones would be fine working in distilled water, but that is a far cry from what is in my bilge!
Thanks for the measurement.

 

[Maine Sail]

I definitely agree, Maine !.. I have a variable speed water pump that draws almost nothing at rest.. and I was wondering how much this switch draws.. My old Rule mercury switch was installed over 20 years ago and still works fine, but one day I'll need a replacement and I think a good electronic one is the ticket. IMHO, the mechanical ones would be fine working in distilled water, but that is a far cry from what is in my bilge!
Thanks for the measurement.

What usually killed the old mercury Rules was the foam inside wetting out... The "switch" portion was very, very reliable, not so much with the new Rule switches..

 

[Blitz]

Me, I'll take a far more reliable switch over cheap junk any day of the week. I replace more failed Rule, and other brands, float switches than just about anything else on boats.. IMHO they are not worth the packaging they ship in..

I've had my share of issues with Rule float switches over the past few years not knowing that the redesign (mercury free) was making them so unreliable. I was wondering should we be concerned about their pumps as well. Or your recommendations on those. I have the Rule 2000 which is at least ten years old. I noticed they have different grades of those pumps as well making them even more confusing.

 

[25yearslater]

Thanks Maine, I will look at the other switches. This will be a direct to battery system without a panel switch. I will also incorporate an inline fuse. I wondered about the 0 volt break since we use these in several 24 volt CNC machining centers. It has it's advantages and disadvantages. YOT never took on water but the peace of mind is worth a few bucks for me.

 

[Maine Sail]

Thanks Maine, I will look at the other switches. This will be a direct to battery system without a panel switch. I will also incorporate an inline fuse. I wondered about the 0 volt break since we use these in several 24 volt CNC machining centers. It has it's advantages and disadvantages. YOT never took on water but the peace of mind is worth a few bucks for me.

You may still want an AUTO-OFF-MAN switch.....

 

[25yearslater]

The little Water Witch is only 2 bucks more than the Rule cheap model at Defender. Thanks and will do with the panel switch. I have a spare on my panel that should do nicely. Thanks.

 

[foolproof]

I would recommend leaving a manual option in the circuit as well. My float switch works as advertised, but will quit before the pump cavitates. Sometimes I want to run more water than that out; when I do, I flip on the manual Bilge Pump switch and I can push water in to the pump to further drain the bilge than what the float switch will do.

My $.02

 

[Blitz]

Looking at the literature does the Water Witch switch NOT work with rain water due to low mineral content? Does anyone have this experience? Many keel stepped masts get plenty of rain water... is this a problem?

 

[Blitz]

Alternatives would be the Water Witch or Ultra Safety Systems switch. I have had good luck with the Water Witch and often install them because Hamilton Marine has them in stock....

Which Water Witch switch do you recommend?? The model 217 seems like you would mount away from the pump or the model 101 which mounts directly to the pump - seems like a good idea? I've always had the troublesome Rule switches and thought I'd give these a try. My current sitch is currently located about two feet forward of the pump and on the other side of a keel stepped mast. My pump is a Rule 2000.

 

[WayneH]

The Water Witch runs for 14 seconds when it activates. In my boat, I had to mount it significantly far from the pump to prevent the pump running dry for too long. So how high is 14 seconds of water in your boat?

Occasionally, my Water Witch gets stuck on. I have to clean under the plate because something gets in there and stays wet and keeps the switch active. I've cleaned it twice in a year. Just run a paper towel between the plate and the box and done.

My bilge pump "Run" light is visible from the helmsman seat and when I see it on, I slowly count to 15 to make sure it's working normally. Any longer than that warrants investigation of the bilge. One of these days, I'm going to hook an alarm to the upper switch.

 

[Maine Sail]

Which Water Witch switch do you recommend?? The model 217 seems like you would mount away from the pump or the model 101 which mounts directly to the pump - seems like a good idea? I've always had the troublesome Rule switches and thought I'd give these a try. My current sitch is currently located about two feet forward of the pump and on the other side of a keel stepped mast. My pump is a Rule 2000.

I prefer the models that allow remote mounting either the 217 or 230. I prefer to mount them higher than you normally would as the 14 second delay handles the rest of the bilge water.