Vintage American outlet

[Charlie]

Ships have a weird electrical system. Someone here might recognize what I'm describing. We don't have a hot, neutral, and ground. If you place a meter in the outlet between the two blades, you get 120 volts. If you place a meter between one blade and the ground prong, you'll get roughly 75 volts, and if you put the meter between the other blade and ground, you get about 65 volts. So, both blades are hot, but, you'd think the two blades would be 60 volts each (kinda like the two legs of a 240 outlet... each one is 120 volts). Instead, the two legs here are 65 and 75 which would add up to 140 volts... however you get 120.

A few years back, I asked the chief engineer about it, then the first engineer and second... not one of them could explain it to me!! All they know is it works as 120 when you put them together. And to think... these engineers have been there nearly 20 years!

So, if any of you electrical whizzes recognize what I described, please explain it.