Isolation Transformer

[muckypup]

I've been told that galvanic isolators are really old hat, and that we should be looking at an Isolation Transformer.

Is this true? Anyone know anything about these? They are probably much more expensive that the standard isolator.
http://www.boatelectric.com/isolation_transformers.htm

Steve

 

[mirage]

From the link you posted:

'Marine Isolation Transformers also give you protection for your onboard electrical/electronic systems from potential shore side hazards including voltage transients, spikes and noise'

which means they are more than just transformers, but there does seem to be a certain amount of marketing BS on the site.

They are also going to be very heavy.

 

[KevB]

I guess it depends on what you want to do. As it's name says and isolation transformer isolates your boat completely from the shore power, so no earth leakage and no nasty spikes (do they happen that often)?

A galvanic isolator just stops the small dc current leaking out through the earth (your boats bits of metal).

So a galvanic isolator protects your boats metal. An Isolation transformer protects your boats metal and stops any nasty electrical spikes.

This is my understanding of the difference, I'm sure someone will correct me if I'm wrong.

 

[beachbum]

You live and learn - I'd always assumed that a "Galvanic Isolator" was an Isolation Transformer...

 

[nedmin]

I have one to smooth the output from my inverter,its only 500watts,but is very heavy,I got mine for £15 from a 2nd hand electrical dealer.normal price would be closer to £100 and thats for only 500watts,for one to carry 16amps ie approx. 4000watts its going to be heavy!! and cost several hundred pounds.They are a good idea if you have the money and can afford the extra weight.

 

[rickp]

The mastervolt terroidal isolation transformers weigh in at around 27kg.

Rick

 

[Geoffs]

Nothing old hat about galvanic isolators, apart from the fact they've been around a long time.

Isolation transformer or not, your boat still needs to be grounded to metal work around you, ie the marina. Otherwise in the event of an elecrical fault, your boat's metalwork could 'float' (electrical float!) up to mains voltage, then anyone who is grounded could get a belt (electrical belt as well!)

A galvanic isolator stops stray earth currents flowing through the water, as, surprising as it may seem, not all earths are at the same potential.

Stray currents flowing through the water=corrosion.