Shore power failure

[2savage]

I've been unable to get shore power working for a few weeks now. After calling the previous owner to trouble shoot, he pointed out that I should be hearing the humming from the transformer. I was not. So, I just bought a Victron 100A 120v/240v transformer to replace the ancient C-Power unit that is probably 33 years old. Since I'm planning on being in the Mediterranean in the future, 240v will be needed. The unit I bought detects input voltage and adjusts as needed to provide the boat with 110v. I'll provide more info when installed.

 

[O C Diver]

So an electrician couldn't work forward from the shore power inlet to determine where shore power ceased? There isn't very much between the inlet and the transformer. I would have thought under an hour to diagnose it. Hope you have a better electrician installing the new transformer.

Ted

 

[twistedtree]

I've been unable to get shore power working for a few weeks now. After calling the previous owner to trouble shoot, he pointed out that I should be hearing the humming from the transformer. I was not. So, I just bought a Victron 100A 120v/240v transformer to replace the ancient C-Power unit that is probably 33 years old. Since I'm planning on being in the Mediterranean in the future, 240v will be needed. The unit I bought detects input voltage and adjusts as needed to provide the boat with 110v. I'll provide more info when installed.

Did you get an isolation transformer, or an autotransformer? What capacity shore connection do you have?

 

[2savage]

Did you get an isolation transformer, or an autotransformer? What capacity shore connection do you have?

I purchased an isolation transformer. My shore connection is 50 amps but I often use a 50 to 30 amp pigtail when 50 amps is not available.

As for the electrician, that would be me.

 

[twistedtree]

I purchased an isolation transformer. My shore connection is 50 amps but I often use a 50 to 30 amp pigtail when 50 amps is not available.

As for the electrician, that would be me.

OK, I guess I'm really confused then. Victron offers a 100A Autotransformer, which is not what's appropriate in this application because they offer no isolation. They also offer Isolation Transformers which would be appropriate, but they are limited to 32A, so would appear undersized for your shore power.

 

[2savage]

OK, I guess I'm really confused then. Victron offers a 100A Autotransformer, which is not what's appropriate in this application because they offer no isolation. They also offer Isolation Transformers which would be appropriate, but they are limited to 32A, so would appear undersized for your shore power.

The confusion is partly due to my poor reply. The isolator is a separate unit that is wired in series with the ground wire to shore power. The actual transformer is the 100a Victron unit you mention.

 

[twistedtree]

The confusion is partly due to my poor reply. The isolator is a separate unit that is wired in series with the ground wire to shore power. The actual transformer is the 100a Victron unit you mention.

I really don't think this is the right application of an autotransformer. It doesn't do any input voltage sensing and switching like you describe, for example. Any chance of a sketch of a schematic showing how this is planed to work? I might still just be misunderstanding what you are trying to do.

 

[Steve DAntonio]

For a vessel of this size you would almost certainly need a transformer with a 240 VAC primary and split phase, 120/240 secondary, it should have integral boosting capability. Is your shore power 100A? If not, you don't need a 100A transformer, and I suspect TT is right, are you looking at a auto-transformer instead of an isolation (technically isolation or polarization) transformer? A 100A shore power transformer is a beast, 250 lbs.

Also, if you plan to go to Europe, make sure the transformer is designed to work on 60 as well as 50 Hz, and even then you can't feed 50 Hz to gear aboard that is designed to operate only on 60 Hz.

Here's an example of what you need https://hubbellcdn.com/catalogpage/WDK_AA-31_CatalogPage.pdf
15 KVA for 50 amp service, with boost, 50/60 Hz.

If you aren't working with an ABYC certified electrician, you should consider that.

These articles may help...

Transformers https://stevedmarineconsulting.com/wp-content/uploads/2019/12/ShorePowerTransformers181-04.pdf

50 vs. 60 Hz https://stevedmarineconsulting.com/...from-a-boat-buying-and-ownership-perspective/