gavanic isolating transformer

[Neil Smith]

Hi all again,

 

My electrician strongly advises the fitting of an isolating transformer to all steel boats but what advantage is there over a galvanic isolator or are neither really needed.

 

Neil

[rogeriko]

Its the earth connection that has to be isolated to stop your boat becoming the earthing point for the entire neighbourhood.

[clbrof]

Airlink do isolation transformers, however they arent cheap!

[nicknorman]

You only need them for when you are plugged into shore power. If you are planning to do that for long periods, they are a good idea. If not, no point.

 

There are pros and cons for GI and ITs. ITs are better in some ways but also more expensive. Again, if you are only going to be on shore power from time to time I would go for a GI. If you are going to be on shore power most of the time, maybe the investment of an IT is worth it.

Edited January 10, 2015 by nicknorman

[EEng]

Isolating Transformers are much better that Galvanic Isolation, no contest really with reliability and peace of mind.

 

You can get cheap ones if you know what to ask for and where to look, by cheap i mean a proper price rather than an inflated price for something used on a boat.

[clbrof]

Where can I find a 'cheaper' one? The one I am looking at is nearly £800 (10kVa)

[Neil Smith]

I was told I only need a 4 kva one.

 

Neil

[frangar]

Where can I find a 'cheaper' one? The one I am looking at is nearly £800 (10kVa)

How many amps is your landline?....given that most inland marinas are 16A...3.6kVA then 10KVa seems quite large even if you have a 32A supply.

 

Cheers

 

Gareth

[rogeriko]

Start looking for a 240 to 240 site transformer. They are blue in colour not yellow like all the 110v ones. But you are still going to have to isolate the earth on the boat, make shure its not connected to the earth on the shoreline.

Heres some info

http://www.bcet.co.uk/marine-isolation-transformers.html

 

Why would you need 10kva that would power a small cruise ship !!!

3600va is plenty http://www.airlinktransformers.com/boating_transformers/

[Ray T]

There are these: http://www.safeshoremarine.com/

 

 

http://www.safeshoremarine.com/Inline%20isolator.htm

 

Plus others on the site. I have no knowledge of them in use, sorry.

Edited January 10, 2015 by Ray T

[clbrof]

Sorry for thread hijack.....

 

Going to wire boat for 32A supply. Will be using 2.35 kw oven, in addition to perhaps 2 kW of electric heaters, underfloor heating, fridge/freezer.

 

Just noticed on airlink they have other 10kVA isolating transformers (non 'boaty') with the same IP rating....

 

boating one im looking at: http://www.airlinktransformers.com/boating_transformers/BT10230/

 

industrial one http://www.airlinktransformers.com/industrial_transformers/enclosed_isolating_industrial_transformers/WN10014/

 

7kva one: http://www.airlinktransformers.com/industrial_transformers/enclosed_isolating_industrial_transformers/WM7501/

 

Would prefer to stay at 10KVa as it means if it is under a 32A load, its not running at full whack, and will hopefully last a bit longer.

 

Can anyone tell me the difference between the boating one and the industrial one?

There are these: http://www.safeshoremarine.com/

Ray those seem to be galvanic isolators?

Edited January 10, 2015 by clbrof

[Ray T]

 

Ray those seem to be galvanic isolators?

 

Yes, it was just for information as Nick Norman was discussing the difference between an isolator and a transformer in post #4.

Edited January 10, 2015 by Ray T

[clbrof]

 

Yes, it was just for information as Nick Norman was discussing the difference between an isolator and a transformer in post #4.

Apologies..... missed that.

[stagedamager]

I've just purchased one of the Airlink 3600VA 230 - 230V isolating transformers, not yet plugged in, but opted for the yellow resin cased one rather than the wall mounted one.

Worth a note however, Airlinks prices are plus VAT, so the one i bought, listed at £250 eventually was much more.

However, buy it through Amazon, and it's £250 inc. VAT!!

Regards

 

Dan

[Neil Smith]

The 3231 model Airlink 230v to 230v one is yellow not blue and rated at 3600kva so is that what I need for a 16a supply or will the 1600kva one do.

 

Neil

[clbrof]

You will need a 3.6 kVA (rating of power, power triangle blah blah long winded stuff) in order to have an output of 16A

 

edit: 3.6kva not 3 kva, thanks nick, I shouldn't be on forum and do uni work at same time.....

Edited January 10, 2015 by clbrof

[nicknorman]

You will need a 3 kVA (rating of power, power triangle blah blah long winded stuff) in order to have an output of 16A

Surely at unity power factor, 16A at 230v is over 3.6kVA and so 3 kVA is not enough?

[Arthur Brown]

Have you identified anywhere that will supply you with a 32A shore supply?

[Neil Smith]

So the 3600kva is the one then and at £250 not a bad price unless anyone knows of one cheaper of course.

 

Neil

[stagedamager]

http://www.amazon.co.uk/Airlink-Transformers-Isolating-Transformer-Corrosion/dp/B00B6ZPMOM

 

Currently not in stock, bugger!

 

Dan

[smileypete]

For a typical narrowboat, why not buy a GI with status monitor from the likes of Safeshore.

 

Unless you really really want an IT.

 

cheers, Pete.

~smpt~

Edited January 10, 2015 by smileypete

[frangar]

So the 3600kva is the one then and at £250 not a bad price unless anyone knows of one cheaper of course.

 

Neil

Sorry to be a pedant...but

 

3.6kVa is what you need...3600kVa is a bit overkill!

 

I knew what you meant but just to be sure?

 

Cheers

 

Gareth

[Neil Smith]

Yes been a long day, lol.

 

Neil

[Keeping Up]

For a typical narrowboat, why not buy a GI with status monitor from the likes of Safeshore.

 

Unless you really really want an IT.

 

cheers, Pete.

~smpt~

 

Seconded. Definitely.

[EEng]

I have said it on here in another thread but an Isolating Transformer is far superior to Galvanic Isolation (with or without monitoring)

 

Yes, new here so sorry if i offend