Ship's electrics reject Genset

[RogerLloyd]

We have shore power and there are no problems. However, when we tried to use an external genset through the shore power lead, the ship's electrical system rejects the AC input and the Leakage Trip Indicator light illuminates. How can one source trip and not the other ? (When we connected the genset directly to an old battery charger all appears to work well.)

[Pete7]

Roger, its like to be either the AC pos and neg are the wrong way round somewhere or its because the generator doesn't have a ground earth. Our Moody displayed a light when we used the Honda 20i.

If its the earth, there has been lots of discussions on this over the years, none really nailed a good solution. Eventually we sold the Honda and went solar, the problem went away.

If you have an inverter, they can be either centre tapped or neutral earth bonded. I had to go neutral earth bonded to get my RCBO to work, otherwise it kept detecting a fault (no earth) and tripped.

Pete

[capt jgw]

Most portables have the floating grounds that cause this problem. Simplest fix is to get a male plug and connect the white and green terminals together with a short piece of wire. Black terminal doesn't get connected to anything. Plug this into the generator's other outlet and it will bond the neutral and ground which is what your panel is expecting to see. I ran a couple portables this way for years. I'm not going to get into whether running a portable on a boat is safe exhaust wise.

[RogerLloyd]

We have reverse current detection, and there was no warning light there, so it looks like the floating problem. Very many thanks to you guys for your expert diagnosis and solution.

[sailorboy1]

To use my Honda via the SP connection requires connecting the common and ground at the generator

[smac999]

Most little gens are floating ground. Which will cause a rev Pol light. But nothing should care or reject that issue that I have ever seen.

Maybe those strange 3 pole breakers some 80’s boats have.