Mike, it might help if you included one of your nice wiring diagrams to show the current paths that result in the neutral current imbalance with the 15 A + 30 A configuration you describe. It is not surprising but a bit hard to visualize how this happens. Will it happen every time or does it depend on how the pedestal is wired? With a 50A pedestal, I assume they need to use both phases but do we know with a 30A pedestal if the 30A and 20A (or 15A) outlets are wired from the same or different phases? My trailer only has a 30A electrical system so I have no experience working with a 50 A connections. Thinking about all of the possibilities makes my brain hurt!
Hi Mike and happy New Year. This is a great article series. Could you by chance continue it with a more detailed explanation of the polarity issue ( I would assume this is improper wiring at the panel) and also how to test for proper/improper polarity in this instance?
That’s true. But both legs would have to be pulling a total of more than 50-amps of load current to overload the neutral conductor.
Since so many readers are confused about how split-phase neutral currents work, I should probably set up a desktop demonstration comparing in-phase additive currents to out-of-phase subtractive currents.
Mike, it might help if you included one of your nice wiring diagrams to show the current paths that result in the neutral current imbalance with the 15 A + 30 A configuration you describe. It is not surprising but a bit hard to visualize how this happens. Will it happen every time or does it depend on how the pedestal is wired? With a 50A pedestal, I assume they need to use both phases but do we know with a 30A pedestal if the 30A and 20A (or 15A) outlets are wired from the same or different phases? My trailer only has a 30A electrical system so I have no experience working with a 50 A connections. Thinking about all of the possibilities makes my brain hurt!
Hi Mike and happy New Year. This is a great article series. Could you by chance continue it with a more detailed explanation of the polarity issue ( I would assume this is improper wiring at the panel) and also how to test for proper/improper polarity in this instance?
Possible Neutral overload if both 30's are on the same leg. (Not likely but possible)
That’s true. But both legs would have to be pulling a total of more than 50-amps of load current to overload the neutral conductor.
Since so many readers are confused about how split-phase neutral currents work, I should probably set up a desktop demonstration comparing in-phase additive currents to out-of-phase subtractive currents.