Running issues

[ndutton]

There's much to be said for potting.

[indigo]

Fuses?

I think there was at least one little glass tubular fuse on the PCB but I cannot say for sure.

+1 on Potting

Tom

[capnward]

Thanks for the photos. Scary stuff. The 'PC board' must be where the positive leads to various locations disperse from a central board. I have something like that, but water can't drip down onto it, since it is attached to the underside of the deck, which is plywood and less likely to condensate than fiberglass. Also, in winter I keep a heater going inside the boat to reduce condensation. What I want to know is, if there was a torch on the vent hose while it was burning, why did it stop, if there was vapor pressure in the tank to keep supplying vapor to the flame? I would have thought that the flame would draw vapor out from the tank. I can only guess that the vapor pressure wasn't enough to keep supplying the flame, and/or there wasn't enough air in the hose for the flame to travel down it. But on further thought, the nature of flame is it needs air at the base, and the hose prevented that, since it didn't burn fast enough. Also the flame would not draw vapor out from the tank unless the fill was open enough to let air in. Anyway, close call. It took me awhile to get 'potting' to mean fuses or breakers. Hadn't heard that one before.

[ndutton]

It took me awhile to get 'potting' to mean fuses or breakers. Hadn't heard that one before.

Nope, that's not what I meant by potting. Using the EWDS as an example, the electronics bundle is placed in a plastic enclosure open on one side and filled with a catalyzed resin to secure the components from vibration, atmospheric conditions and moisture. The finished EWDS module resembles a small black brick but there is plenty going on inside. Encapsulated or potted as described I'm confident the EWDS module would pass an ignition proof test (propane environment).

Had Tom's circuit board (I assume a prototype of some sort) been potted I expect it could have been submerged without ill effect.