Shock-Drowning Potential

Originally posted by techntrek Sorry, I meant the two things to be separate.  N-G bond or not, an inverter or generator that is completely isolated from the physical ground (no ground rod) wouldn't allow a circuit to be completed between the hot and a person standing on the ground. I'm sure you are right since MSW's are built as cheaply as possible.

But you've raised a very interesting question that I don't know the answer to. I have the contact info for a few engineers at Xantrex, so maybe they can enlighten me. 

Originally posted by techntrek I'm not so sure there would be a problem here...  A note on the inverter itself, it is likely a modified sine wave inverter so it will not have a bond between neutral and ground.

Maybe, but maybe not. Even though a modified sine wave inverter may not be N-G bonded, that doesn't mean there's complete isolation from the neutral. However, I would have to run some actual leakage tests to be sure. I'm not sure why there's a neutral bonding difference between sine and modified sine inverters, but it's got to be money related. I'll call one of my inverter engineering buddies and see just why.

Originally posted by shroomer Thank you. I appreciate the response and explanation. I'll try not to test it out those scenarios though.

Yeah, you really don't want to use yourself as the test subject. Here's a picture of "Flash" who is an action figure (not a doll) I built with a flash bulb for a head. Yes, you can still buy flashbulbs for $1 on eBay and they go off with a big "whoosh". I use Flash in my No~Shock~Zone seminars to demonstrate what happens when you get across a voltage and ground source at the same time. He's OK with it since I can always pop in a new flashbulb. But you may not be so lucky if you get sufficient current across your heart. If you ever feel ANY shock from an appliance or RV, no matter how small, stop immediately and power down. And read all my electrical safety articles at www.NoShockZone.org for a better understanding of electricity and how it works.

Originally posted by shroomer Here's an electrical safety question for y'all. I pump water from rain barrels on my pickup into a large tank at my garden. To do this, I use a submersible sump pump, 120volts, 250 watts. I get the volts from a 1000w inverter that I hook up to my battery via jumper cables. Seems like I have all the ingredients for a good shock if things go awry. What sort of protection should I use? A GFCI on the extension cord enough?

Actually, what you're doing is relatively safe but adding a GFCI would make it even safer. Here's why...

Since your entire system is floating, even if you touch a bare "hot" wire of your system while standing in water there won't be any current flow and thus no danger. However, if there's a failure in the water pump while it's "grounded" in water, then your vehicle "ground" would be elevated to 120-volts creating a hot-skin condition. So touching your now-electrified vehicle while standing on earth could electrocute you. Yikes...

However, by adding a GFCI extension cord feeding your 120-volt pump, if there's an insulation failure in your pump and your vehicle is hot-skin electrified, then touching it would cause sufficient current to flow allowing the GFCI to trip. I would consider that scenario to be perfectly safe and pretty easy to do since you can get an extension cord with built-in GFCI for $30 or so.

Seems upside down and crazy, but that's how it works. This is one of the demonstrations I would like to do in my No~Shock~Zone seminars

I'd probably just use a 12V bilge marine bilge pump to remove worries about shocks and the need for the inverter.