Replacement or repair of the Scheiber 110 to 230 volt transformer

Derick Gates SM2K #400 Brava

Kent (Rusty),

Brava does have the same set up on the engine room bulkhead where you have to switch the plug between shore power 110 Volt input and 220 volt input, but forgetting to do that is not the issue in this case.  Thanks for asking.  Leaving the unit unplugged would indeed be the type of thing I would do...

Hope you have reached the end of your chain by now and all has returned to normal in the chain locker.



Ben and Gayle Super Maramu #347

I have the same setup transformer in my boat.  So far, I have not found a marina in the Caribbean that does not have 220v power so I have not used it.

I do have a question on this transformer:  when one has this unit, does it serve as an isolation transformer as well as step-up unit?  It does seem having this unit wired between shore power and the boat may isolate the boat from stray currents ... but not sure.  I would be great to a more educated opinion.

Ben Driver

La Bella Vita

SM #347

Derick Gates SM2K #400 Brava


As a followup to my original post, I have not yet tackled removal of the 110 volt to 230 volt transformer to see if it can be repaired, nor have I been able to find any blown fuse or tripped circuit breaker on this circuit. This has been a low priority because instead I have been able to find 220 service throughout the Caribbean, and use the 220 cable instead with the appropriate US or EU adaptor.  

Nonetheless, when I installed a metered galvanic isolator like the one BeBe (Bill Rouse) posted in the photos section, I had the electrician install it next to the 110/220 volt plug box on the engine room forward bulkhead, connected in series to the ground outgoing cables in such a way that it would operate no matter whether the 110 volt cable or the 220 volt cable was in use.  Thus, no matter which cable is connected to shore ground, the galvanic isolator is connected and functioning to prevent stray current via the shore ground.

I realize that this response does not directly answer your question about whether the 110 to 220 volt transformer acts as an isolation transformer.  That question is beyond my expertise.  However, I do know that the ground wires coming into the 110/220 volt plug box on the engine room forward bulkhead go to a common point within that box, and I therefore expect that stray current/voltage from either of the shore cables would enter the boat undeterred by the presence of the 110 to 220 volt transformer (and hence the need for the installation of the galvanic isolator).  

I hope others with more electrical knowledge than me will address your question better.

SM2K#400 Brava
"Currently" in Sapphire Beach Marina, Saint Thomas, USVI