Autotransformer voltage too high

DIY
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1

I am using the Victron Isolation Transformer 3600W auto in the US and the Caribbean (120V) grid on a boat that has a 230V system for its appliances.

I am experiencing that in many marinas, the shore power that is supplied has a Voltage that is around the 130V mark. I am also experiencing that the Victron cuts off if the input power is above 126-127V (which is I think the nominal design voltage of 115V plus 10%). This presents a big problem as we can never be sure when we visit a marina, that we will have useable shore power.

Does anyone have a solution for this? Are the newer isolation transformers accepting a wider range of voltages or are there other products available that don’t have this issue?

PS I have already changed the wiring inside the Victron that normally boost the output with 6% and I reversed it so that it now bucks the output with 6%. So I am not worried about my appliances.

2

What is really needed to accommodate high/low shore power voltages is a transformer with multiple taps so that the incoming voltage can be adjusted ahead of the inverter and loads. Victron does not make such a device but they are available from more typical electrical supply houses.

There are also voltage regulator devices that have multiple tap transformers that select the best tap automatically.

For the best option for a boat visiting multiple ports with varying shore power voltages and frequencies is to use a separate charger with a wide voltage and frequency range and run the inverters without a shore power connection. That way the loads always receive the proper voltage and frequency. But the solution is expensive and takes significantly more space.

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