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gls avatar image
gls asked

Autotransformer - US to Oz

I am converting a US wired boat to Australian and I want to ensure I am code compliant for the time I return to Australia. I have a 110/220V 60hz generator and 230v 50Hz shorepower. I am not overly worried about the frequency as I can get most equipment as dual 50/60Hz, and those that I can't I will forego.

I will replace my breakers to be all 2 pole, replace the wiring to be colour compliant and install RCD's. My question is can I use an autotransformer to combine the two hot legs from the generator into a single 220v source and the autotransformer then provide the missing neutral?

The autotransformer would be placed between the generator and the source selector switch.

Converting power on boats is a huge topic but I haven't seen this idea being suggested - that tells me I might be barking into the wind!

Grateful for thoughts and feedback.

Autotransformer
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2 Answers
kai avatar image
kai answered ·

An autotransformer doesn't have isolation so the L2 output leg will still be live relative to the transformer's mid point tap. It will give you a neutral reference but I don't know if the overall outcome is what you're looking for.

I suggest that you should investigate the compliance scope for AS 3000 (& AS 3004 by reference) with a suitably qualified marine engineering company. If you need to literally rewire the boat to AS 3000 using the deem to comply (Part 2) provisions, you might end up having to gut the entire existing 110V/230V system to be fully compliant.

If the engineering company is happy to effectively declare compliance through a Part 1, then you may only be up for localised modifications if any.

In either case the AS 3000 compliance activity is unlikely to be a DIY thing, sorry to say.

Edit: I will say that while AS 3000 is applicable for all electrical systems in Australia, the regulatory regime zeros in on voltages > 50VAC and 110VDC (hope I got the thresholds right!). Your 12V, 24V and 48V systems should largely come through unscathed.

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gls avatar image
gls answered ·

Thanks Kai, more work to do!

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