Shore power issue

Dean Gillies


Today’s job was to replace the impeller in my generator.  It was shredded, so I opened up the heat exchanger to clean it too, it was gunged up badly, so after cleaning all that I had a look at the exhaust elbow too, and cleaned that out as well as the muffler. Great. Put everything back together, and started the genny to test.  Generator worked fine but ...

I forgot when starting the genny we were still running some things on shore power.  The genny seemed to override shore power (as it should I believe), however, on shutting down the generator, the shore power no longer works.

I’ve checked the dock supply and the stern breaker - both good. But I get no light on the 240v panel.

I’m thinking the changeover switch has somehow stuck, but why, where is it, how to reset it ?

Or have I smoked the changeover switch by firing up the genny while shore power is running?

So many questions!

Thoughts ?

Many thanks


SY Stella

AMEL 54 #154



We had that same switch fail in a similar fashion on our Super Maramu.  On the SM, this changeover switch is located in the engine room on the port side right outboard of the generator.  It is in a gray electrical box labelled "Quai-GE" and "220 Volts" mounted on a wood board.  See the attached picture (courtesy of Bill Rouse).  I do not know if it is the same switch or is mounted in the same location on the 54.  

We ended up replacing the auto-transfer switch with this manual break-before-make switch:

It is a much more robust switch but it does require that you actually go into the engine room to switch from Shore Power to Generator Power.  However, that is fairly infrequent and it has been pointed out to me that is not such a bad thing as I should be checking the oil before starting the generator anyway.  

Hope this helps.

Mark McGovern
SM 440 Cara
Deale, MD USA