Smoke in the Cabin

Hi folks,
I was just down in La Paz for a short week of projects aboard Harmony. Well, one morning I was listening to the morning net and enjoying my coffee, when I noticed a light haze of smoke and the smell of electrical insulation burning. Yikes!

I quickly grabbed a flashlight and began a methodical search of the boat. No obvious causes were found in the main cabin and forward and aft staterooms, so I headed into the engine room, where the smoke was a bit thicker. I checked the AC cooling pump, as it had been running since I came on board, but that wasn't it.

I found the problem to be my main freshwater pump. It is a 5gpm automatic pump that used to be sold by WM. The problem was that the sealed pressure switch somehow had some water leak in and short it out. The switch is in the center of the end shot of the pump. I am including the model # and other info in the pictures just as a FYI for those of you who might have the same pump.

Luckily, I was comfortably tied to the dock, and not underway at night in stormy seas. I was able to swap out the pump with a similar spare carried onboard, and I ordered a new replacement, to be delivered and installed on my next trip down.

I also discovered that my 2 gal accumulator had developed several small rust holes/leaks, so I ordered a new one of those also. Strangely, none of my smoke detectors had gone off yet. Maybe I found the problem early?

Anyway, just sharing my experience.

Cheers, Bill

Montenido said:

Strangely, none of my smoke detectors had gone off yet. Maybe I found the problem early?

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Maybe you found your smoke detectors had exceeded their useful life. 10 years is supposed to be the end of use date for the sensors.

You can usually smell things or see smoke long before the detectors go off.

The minute a pan starts smoking in the galley doesn't mean the detectors go off at that instant.

Asleep...all bets off...especially depending on sleeping quarters.

I once had a 14 ga wire brown about an inch long...just browned....it was to the helicopter landing gear and it caused so much smoke I lost sight of the copilot just 4 feet away. Amazing how much smoke us produced in such a short amount of time and so little oxidation of the fuel.

So the wires develop a short get overheated and burn.
What is the amp draw on the pump, what is the breaker rating? Is you OCP device too high of a value? Wires too small? From the pic, says use a 15 amp fuse, motor draws 11.2 amps max.

If I am not mistaken you are using an "on demand" pump. Which means that it runs when it senses a demand. No accumulator tank is needed and often if one is used it interferes with the pumps designed cut/in cut/out characteristics. Especially if there is a minor leak in the Accumulator tank. The pump will continuously run at very slow speed. That may have been the original problem and not water on the switch. You should also fuse the line in to the pump if not already.

@Montenido

If I may give you a personal tip which tops my security list aboard :
At the dock In the event of smoke or a smell of smoke, immediately shut off the power AC & DC, then and only then, investigate.

P.

Pilou is correct

At the dock In the event of smoke or a smell of smoke, immediately shut off the power AC & DC, then and only then, investigate.

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Absolutely the first thing to do in any fire, especially an electrical fire is kill all the circuits. Dockside you can kill everything with your main breaker(s) and master switche(s).

At sea kill all non-essential circuits. In calm weather that would be everything.

Montenido, be careful

....so I headed into the engine room, where the smoke was a bit thicker.

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When entering a suspect space do it very carefully. Feel the surface of the door / hatch with the back of your hand. If you have a dogged opening crack the dogs enough for a small gap and check again. Introducing fresh air to a fire can be very dangerous.