E27 12DC Negative Ground - 10A Fuse Tripping

[jhackbar]

I recently purchased an E27. I have run the bilge pump about three times by turning the battery switch to on (1,2,or ALL) and then turning on the 10A switch on labeled "Bilge Pump Aft". This was with the 20A Main All turned to on.

Now when I trip the 10A switch it stays on for a few seconds and then the switch trips to off. Not sure where to start? Is there a fuse that is blown? Should I see if the bilge pump is getting power? The batteries are charged up so I am not sure what would cause a fuse to trip to off automatically.

Thanks for your help!
John

 

[toddster]

Well, normally that means that the bilge pump is drawing more than 10 amps, so the circuit breaker opens to prevent the wires from melting. The pump might be filled with crud, or the bearings might be worn out. A loose electrical connection or frayed wires could also cause a trip when they heat up from the load. You'll have to go over the circuit and investigate.

The battery switches on these boats are wired up all sorts of different ways, and it might not have any effect on your 12V panel. In fact, most people these days wire the bilge pump with an automatic float switch and its own direct connection to the battery*, so it will still work when you shut the rest of the system down.

* (fused of course)

 

[jhackbar]

Thanks for the ideas. I will first try to make sure it isn't clogged up tomorrow. Hopefully that works and if not I will provide additional information.

Thank you for your help and quick response!
John

 

[Jaytanz]

Direct wired bilge pump

I have my pump wired to the batteries, so that even when the 1/2/All switch is in the off position the pump will work. I once was working in the bilge area and lifted the float switch to get below it and my cabin lights came on. So, I had left the lighting breaker in the on position and when the bilge circuit was completed it connected service to the rest of the panel. My question, and apologies if I am hijacking the thread a bit, is: am I wired incorrectly somehow? Sorry, pretty sure I am wired incorrectly, but is my boat?

 

[toddster]

I have my pump wired to the batteries, so that even when the 1/2/All switch is in the off position the pump will work. I once was working in the bilge area and lifted the float switch to get below it and my cabin lights came on. So, I had left the lighting breaker in the on position and when the bilge circuit was completed it connected service to the rest of the panel. My question, and apologies if I am hijacking the thread a bit, is: am I wired incorrectly somehow? Sorry, pretty sure I am wired incorrectly, but is my boat?

Er... yeah. You might want to get that sorted out. :0

Normally a bilge pump is wired up with a 3-position switch that connects the pump to the hot bus directly, or through the float switch, or disconnects it. If you have the float switch wired directly to the battery and the other switch wired to the 12V panel, you could have them both "on" at the same time. The problem with that is if you leave everything as you describe, and the float switch is activated, the bilge-pump wires are now acting as the primary battery wires to the whole boat. They're probably not big enough for that, so they could melt down and start a fire*.

Other (remote) possibilities might be that the hot wires of those circuits are actually shorted together, or that someone has put one or more switches on the ground side of a device. Some light switches in cars are wired up that way. If theres a bad ground connection somewhere, current can flow in unexpected directions. (I still haven't figured out how the glow plugs in my old GMC truck activate the windshield wipers.)

*except of course, you've fused them properly, so the fuse blows, the bilge pump is deactivated, and the boat sinks.

 

[Jaytanz]

I am going to sail her to the new slip today. I will definitely check the wiring. Thank you.

 

[TRMN8R]

Been reading this with great interest. Since owning my e27 now for five years, anytime i ran into issues like this, I ripped out the wiring and ran my own proper wiring with switching, yes I understand dc wiring very well. Eg, when I decided to install a bilge pump a year ago, I designed the electrical through a three position switch on the panel. Wiring direct to battery properly fused, one side of the sw wired via the float, the other side momentary contact on (manual), and off. In the end, given what PO's typically do with wiring jobs, if anything is suspect or causes probs such as what you are experiencing, don't waste your time with a potentially dangerous situation, remove and rewire properly yourself! Hope this helps!

 

[Jaytanz]

Ok, not a bad situation. I must have been messing with things a bit when this happened. The float switch is wired to the 3 way switch, and the pump is wired to the manual switc/breaker. I must have had the bilge pump and cabin lights switched on with the batteries off, and then lifted the float. That powers up the panel, which to my understanding would be unavoidable. So, as I now always turn off all breakers/switches as well as the 3 way, I should safe.Thank you,Oh, got her to the Magothy Marina today. Initial impressions: Great place, great people, really looking forward to the summer.

 

[jhackbar]

Water Puppy Bilge Pump

UPDATE: More info on my bilge pump. It is a Water Puppy Impeller Pump and installed under the seat in the cockpit. I checked the fuse and it looks good.

I think next steps are to check the voltage is running to the pump. If that is okay then I will pull the hoses off and check out the pump as it could need a new replacement impeller?

 

[Phil Adams]

Looking at your photo's the pump looks like it has a fuse rating of 15A? If the initial load is greater than 10A it will trip the circuit breaker each time so you could try simply connecting it to the cabin lights circuit (15A) and see if this clears the problem for you. On Trithena (E27) I've fitted a whale 500 auto bilge pump with an auto/manual switch wired direct to the battery which works fine and gives peace of mind whilst she's out on the mooring!