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More Breaker Panel Mess
chuck wrote in news:hAskf.8744$N45.1460
@newsread1.news.atl.earthlink.net: What happens, Larry, is that your fridge cabinet is connected to the green equipment grounding conductor and to an AC ground/neutral junction on land. Your engine is connected through the water to the hot AC wire on the neighboring boat. The voltage between those two pieces of metal could approach 120 volts. Even a zinc/copper galvanic couple will result in a measurable potential difference in seawater. No need for massive currents and no need to think in terms of raising the potential of the whole ocean. :-) Negative. The green wire is connected to EARTH GROUND. The engine is connected to EARTH GROUND, too! The seawater IS EARTH GROUND!....and a nice one it is. Your idea of floating the ocean 120VAC above that grounded fridge cabinet just isn't gonna happen.... Hook a big ground symbol to the prop...That's the circuit.... Here, a much safer test. Plug the boat into the dock but leave the other end unplugged from the boat. (leave the breaker off to be safer as we're fooling with ground, not AC. Measure the resistance from the engine block in the boat to the ground in the dropcord to the dock ground. Unless you have a rubber shaft coupler somewhere...you'll find the resistance VERY low through the water....salt water. Still think the engine isn't grounded through the underwater metals? Turn on the breaker and touch the black hot wire to the engine block and tell me how big an arc it draws for you. Be careful the melting black wire doesn't burn you....ok? |
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