Fried 110v outlet in bilge

Four Suns

Not a pot stirrer
TECHNICAL Contributor
Oct 4, 2006
10,533
Williamsburg, VA
Boat Info
2003 480 DB
Engines
QSM-11 Diesels
I was down working on my boat today and had a shop light and electric drill (with a wire wheel on it) plugged into the 110v outlet that is in my bilge. It is a standard Sea Ray install... came with the boat. The plug is wired to a GFI up in a locker in the cockpit and then to the electrical panel inside with a 15A breaker. All seems good... remember that the boat is diesel so it's ok to put a plug in the engine room.

So I'm working today and the light goes out and the drill stops. The GFI won't reset so I thought the GFI was toast and went and bought a new one and installed it... worked... but still no power to the plug in the bilge. I pulled the cover off the 110v plug and OUCH!


DSC_0419.jpg


The plug is melted where the white wire attaches. I should say "was attached" as it was burnt right off the thing. If you look closely at this wire, the thing was stripped back about 2" instead of being flush into the fitting like the black and green wires... Very poor install job.

closeup.jpg


This exposed wire was very corroded as see with the green copper oxide on the wires. It was actually stuck to the bottom of the electrical box and it appears moisture had gotten in this thing and the bare wire sat in it and corroded. Note there is nowhere for the moisture to drain in that set up...

I actually used to use this plug to drive two XTreme boat heaters in the winter. I now have Wolverine oil pan heaters and a single XTreme but they are hard wired into the panel now. I'm lucky this thing didn't catch the boat on fire.

I think this is a great example of why you don't want to put a 110v plug into a gas engine room to run boatsafe type heaters (or battery chargers, etc.). Any corrosion on the wires and BOOM! It also shows why any 110v splices need to be in properly rated UL boxes and not just left in the open with some shrink wrap on them.

The weekend is here... needed some controversial topic to discuss. Like a non-GFI plug installed in a gas engine room and a battery charger plugged into it (i.e. a "cool mod" we should all remember)...

I'm going to run a new 12g wire circuit to this plug tomorrow and rotate it so moisture can drain out the bottom at the strain clamp...
 
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It seems this corrosion problem could be avoided if ring terminals with adhesive shrink wrap were used to terminate the wires in these harsh environments. Basically, the wires are stripped and compressed in the plug connector but the wire is still exposed/bare with the part in the plug. I'll probably put it back together with the ring terminals so the wire is sealed. I should probably go through all the 110v plugs/GFI circuits on the bridge and cockpit and "upgrade" them and terminate the wires with heat shrink ring terminals...
 
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I'm going to run a new 12g wire circuit to this plug tomorrow and rotate it so moisture can drain out the bottom at the strain clamp...

Great, now I have something else to worry about.

I think rotating it would make it easier to use anyway, so the doors hinge on the right.
 
Forgot to ask, what were you wire wheeling?

Also, what about spraying it with that anti corrosion stuff that's on all the low voltage stuff (after you fix it)?
 
I was cleaning the through hull for the depth sounder. The green bonding wire terminal screw broke off so I need to clean the flange and drill/tap a new screw hole and fix that corroded bonding wire...
 
I was down working on my boat today and had a shop light and electric drill (with a wire wheel on it) plugged into the 110v outlet that is in my bilge. It is a standard Sea Ray install... came with the boat. The plug is wired to a GFI up in a locker in the cockpit and then to the electrical panel inside with a 15A breaker. All seems good... remember that the boat is diesel so it's ok to put a plug in the engine room.

So I'm working today and the light goes out and the drill stops. The GFI won't reset so I thought the GFI was toast and went and bought a new one and installed it... worked... but still no power to the plug in the bilge. I pulled the cover off the 110v plug and OUCH!


DSC_0419.jpg


The plug is melted where the white wire attaches. I should say "was attached" as it was burnt right off the thing. If you look closely at this wire, the thing was stripped back about 2" instead of being flush into the fitting like the black and green wires... Very poor install job.

DSC_0418.jpg


This exposed wire was very corroded as see with the green copper oxide on the wires. It was actually stuck to the bottom of the electrical box and it appears moisture had gotten in this thing and the bare wire sat in it and corroded. Note there is nowhere for the moisture to drain in that set up...

I actually used to use this plug to drive two XTreme boat heaters in the winter. I now have Wolverine oil pan heaters and a single XTreme but they are hard wired into the panel now. I'm lucky this thing didn't catch the boat on fire.

I think this is a great example of why you don't want to put a 110v plug into a gas engine room to run boatsafe type heaters (or battery chargers, etc.). Any corrosion on the wires and BOOM! It also shows why any 110v splices need to be in properly rated UL boxes and not just left in the open with some shrink wrap on them.

The weekend is here... needed some controversial topic to discuss. Like a non-GFI plug installed in a gas engine room and a battery charger plugged into it (i.e. a "cool mod" we should all remember)...

I'm going to run a new 12g wire circuit to this plug tomorrow and rotate it so moisture can drain out the bottom at the strain clamp...

You can also drill a 1/4" drain hole in the box Gary. That is what we do to PVC service entrance LB conduit fittings.

~Ken
 
How are your other connections looking down there?
 
How are your other connections looking down there?

They all look fine from what I can tell... Sea Ray sprays that goop all over everything to protect it. Bare wire that sits in water is bad news though...
 
You can also drill a 1/4" drain hole in the box Gary. That is what we do to PVC service entrance LB conduit fittings.

~Ken

I was thinking that too, maybe even a couple of smaller holes. But do you think that much water will accumulate in there? Or is it just the salt air?

Just looked at Corrosion X, it has a 20,000V dielectric rating. So it should be fine to spray the back of the outlet with.
 
Pardon my ignorance but I've got to ask...

I can understand moisture in there but enough that "wire sitting in water" & the need for drain holes? Did the poor install & resulting overheating cause so much condensation?

Go easy on me - I'm learning as fast as I can.
 
Moisture could get in there several ways. The box isn't sealed at the wire input. I've had several things happen over the years that required cleaning and spraying the area down. If I get any kind of oil leak, raw water cooling leak, etc, it will happen right over the spinning shaft spraying crap all over the engine room. I learned the first few months I had the boat why Sea Ray put a fresh water hose bib in the engine room.

So... I think it "just happens" when one cleans the engine room/lazarette area and all this stuff should drain and dry properly... this plug did not.
 
If the neutral was leaking voltage into accumulated water at the bottom of the box, shouldn't the GFCI upstream have tripped before the receptacle burnt up?

Something doesn't sound right, unless the GFCI in the locker was defective to begin with?
 
Moisture could get in there several ways. The box isn't sealed at the wire input. I've had several things happen over the years that required cleaning and spraying the area down. If I get any kind of oil leak, raw water cooling leak, etc, it will happen right over the spinning shaft spraying crap all over the engine room. I learned the first few months I had the boat why Sea Ray put a fresh water hose bib in the engine room.

So... I think it "just happens" when one cleans the engine room/lazarette area and all this stuff should drain and dry properly... this plug did not.

Or maybe some stalker dude was placing a “Booby Trap”
 
Interesting topic since I am just in the process of adding a couple more circuits to the E.R. I only have a 240v space left for the breaker so I'll split off two 120v circuits in the engine room. (I need one for my Wolverine heaters)

I checked the existing GFI and the terminals had proper crimped ring connectors. Boy, am I glad I bought a 'Dancer rather than a bridge boat, LOL.:grin:
 
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I'm surprised you didn't get a whiff of the outlet baking....remember the song on this album? Glad you caught it, you should play the lottery this weekend.

360569445169846524.jpg
 
Well, that sure is a good case for no outlets in the ER.

tobnpr has a good point. Wonder why the upstream GFCI did not trip.

Does anyone make one that is safe for a gas guy?
 
I don't believe there is any receptacle approved for use below deck in a gas boat. Just the act of putting a plug into a receptacle often generates a spark.
 

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