I have noticed this problem occasionally over several years with our ST6002. Maybe once a day at most. Nearly always when sailing.
Since we fitted solar
, the problem has reduced markedly to once in 4 weeks, so as others have said it seems almost certainly due to a momentary voltage drop. My view is that it occurs when the fridge kicks in requiring a large inrush current
in coinciding with the pilot actuating, but have not conclusively verified that. Fortunately, I get a loud audible alarm from the chartplotter
, so it is a nuisance rather than a danger
I have contemplated fitting a large ~1 farad capacitor like the tw*ts fit for their mega power car boom boxes. Fitted to the DC switcboard 12V input which is remote
from the batteries. That way, the feed to the instruments and other consumers should remain steady and allow large short term current
draws without voltage dips. They are readily and cheaply available and easily fitted .