Isolation Transformer Wanted

[Leonora Davy]

It seems that I might need an Isolation Transformer.

 

The one I have my eye on is the Victron 230V 3600W p/n SDIT0036000.

 

From what I've seen on the forum boat community there appears to be a small amount of indirect trading going on between boat owners and suppliers who are both members of the forum.

 

Before I start ringing around Victron agents, etc, are there any discount arrangements between supplier members and boat owner members ?

 

I appreciate that this might not be allowed by the forum rules and I've no wish to compromise this, but perhaps any suppliers of Victron equipment might like to PM me ?

 

At the end of the day, Victron will get the business, but I might as well put the business the way of a member rather than a stranger.

[Gary Peacock]

We offer discount to boat clubs and charities, I don't have a problem offering the same discount to CWF members but this would be better negotiated by email away from the forum.

[reg]

It seems that I might need an Isolation Transformer.

 

The one I have my eye on is the Victron 230V 3600W p/n SDIT0036000.

 

From what I've seen on the forum boat community there appears to be a small amount of indirect trading going on between boat owners and suppliers who are both members of the forum.

 

Before I start ringing around Victron agents, etc, are there any discount arrangements between supplier members and boat owner members ?

 

I appreciate that this might not be allowed by the forum rules and I've no wish to compromise this, but perhaps any suppliers of Victron equipment might like to PM me ?

 

At the end of the day, Victron will get the business, but I might as well put the business the way of a member rather than a stranger.

Hi Leonara

I have sent you a personal message with details of a boxed Victron Isolation transformer that I will not be using, hope this helps

regards Reg

[GUMPY]

It seems that I might need an Isolation Transformer.

 

The one I have my eye on is the Victron 230V 3600W p/n SDIT0036000.

 

 

Be very careful with this item there is an inherent fault in the primary wiring of the Victron transformer.

Get it rewired by a competent electrician who really knows what he is doing.

The reference is her for those that don’t believe me.

 

http://www.smartgauge.co.uk/iso_wire.html

 

This fault could cause the hull of the boat to go live.

 

 

Julian

[John Orentas]

Be very careful with this item there is an inherent fault in the primary wiring of the Victron transformer.

Get it rewired by a competent electrician who really knows what he is doing.

The reference is her for those that don’t believe me.

 

http://www.smartgauge.co.uk/iso_wire.html

 

This fault could cause the hull of the boat to go live.

Julian

 

 

Leonora.

 

The question of isolation transformers and their effectiveness is still a topic of debate, if you are looking for a means of stopping your hull from corroding a better investment may well be for a few gallons of paint.

 

If it is the safety issue that concerns you then the question is even more arguable as you may see from the Smartgauge article and depending on how you choose to wire it the safety devices we are now all used to may not function at all.

 

There is a way to make the 230 volt system on your boat very much safer but for some reason not known to me the 'Trade' will not even consider it. Not much money to be made ?

Edited July 31, 2006 by John Orentas

[ChrisPy]

 

There is a way to make the 230 volt system on your boat very much safer

I'm intrigued..........

well, go on, let the cat out of the bag John

[GUMPY]

There is a way to make the 230 volt system on your boat very much safer but for some reason on known to me the 'Trade' will not even consider it. Not much money to be made ?

 

The only totally safe way to have a 230v system on your boat, is NOT to have a 230v system on board.

 

What is this wonderous method of making 230v safe on board that you have found.

Please enlighten us.

 

 

J

[John Orentas]

I'm intrigued..........

well, go on, let the cat out of the bag John

 

 

Hi Chris.

 

I have mentioned it on the forum before but not recently. A transformer with 230 volt primary and a centre tapped 110v - 0v - 110v. This system is exactly what the more sensible European countries do for their domestic power supplies. All appliances and lighting will work normally (all our domestic appliances are exactly as sold in the rest of Europe).

 

The difference being you can stick your pinky into any plug socket and the only shock you can ever experience is one of 110 volts, no more that a tingle to most people.

 

Only in this country do people, mainly children die from electrocution in their homes.

 

When this country adopted the 13 amp ring main system we missed a great opportunity to change to a rational system. 230 volt live - 0 volt neutral - 0 volt earth. Think about it, it's rubbish, a product of a diseased brain.

[ChrisPy]

A transformer with 230 volt primary and a centre tapped 110v - 0v - 110v.

I assume that to do that you need the isolation transformer in the supply line, but with some re-wiring. Feeling particularly thick today (hot in Turkey, and the brain is receiving too much input today on various matters that I won't bore you with), so how easy is it to do?

[John Orentas]

I assume that to do that you need the isolation transformer in the supply line, but with some re-wiring. Feeling particularly thick today (hot in Turkey, and the brain is receiving too much input today on various matters that I won't bore you with), so how easy is it to do?

 

 

Well you would need a special transformer but it's quite a routine job for a manufacturer. 'Isolating transformer' is something of a misnomer, all transformers isolate the term simply means that there is no direct conductivity from primary to secondary and probably the insulation standard is higher.

 

What you need and what you would get is 2 phases each of 110 volts.

[GUMPY]

Hi Chris.

 

I have mentioned it on the forum before but not recently. A transformer with 230 volt primary and a centre tapped 110v - 0v - 110v. This system is exactly what the more sensible European countries do for their domestic power supplies. All appliances and lighting will work normally (all our domestic appliances are exactly as sold in the rest of Europe).

 

The difference being you can stick your pinky into any plug socket and the only shock you can ever experience is one of 110 volts, no more that a tingle to most people.

 

110v is still easily enough to kill you, which is why builders transformers are 55-0-55 if 110v was safe then they would be 110v without the centre tapped earth. As for it being widespread in Europe, not any more it isn’t. There used to be many places that had what is in fact delta power as opposed to star that we use here, I can now only think of a few, Parts of Oslo parts of Belgium and parts of France.

Most of Europe now uses the same system as us i.e. a 5 wire 380volt star system rather than 3 phases of 130volts and Earth.

Also there are some items that will NOT work when there is voltege between neutral and earth even though they are CE marked, the most notable of these are computer UPS that detect for voltage between neutral and earth.

 

The major problem with you idea is that it would be more expensive than using a standard iso transformer with one side bonded to the boat earth. The reason is simple, to comply with BS7671 ( the IEE regs) you would have to have the following:

 

All the sockets and 230v switches would have to be double pole and switch both sides of the supply most do not.

 

All the breakers would have to be double pole and would have to disconnect both sides if a fault current appeard on either side. this would greatly increase the cost of the consumer unit as it would have to be twice the size and the breakers are well over double the price of a single pole one.

 

 

Having looked at this, the safest way is to use an isolating transformer ON SHORE as close to the supply as possible, not in the boat. This should be supplied through an RCBO and wired so that the case and the screen of the transformer are connected to mains earth. The secondary should have the boat earth wire connected to one side of the transformer output making this side of the transformer in effect the neutral, this should then feed through another RCBO at the transformer to the boat. At the boat the earth wire should be bonded to the hull and then there should be another RCBO to protect the boat.

 

Yes it might seem like overkill but it’s the safest way.

 

 

Well you would need a special transformer but it's quite a routine job for a manufacturer. 'Isolating transformer' is something of a misnomer, all transformers isolate the term simply means that there is no direct conductivity from primary to secondary and probably the insulation standard is higher.

 

All transformers do NOT isolate

there are two types of transformer

1: isolating where there is no direct connection between primary and seconday

2: auto where the transformer can consist of one winding or there is no isolation between primary and secondary.

 

J

[GUMPY]

Having just checked my work files, 220volts (using 2 phases of 127v) is also still available in parts of Italy, Sweden and Spain. However Norway no longer has it.

 

J

[ChrisPy]

sorry I asked ..........................

[dor]

Good reply J, very informative. One question out of interest: I understood at one time that the US 110V system was also 55-0-55, i.e. centre-tapped (or should that be center-tapped as we are talking about the US?). And this was the reason it was inherently safe compared to our system. Is this the case, or do they have 110V to ground?

[GUMPY]

Good reply J, very informative. One question out of interest: I understood at one time that the US 110V system was also 55-0-55, i.e. centre-tapped (or should that be center-tapped as we are talking about the US?). And this was the reason it was inherently safe compared to our system. Is this the case, or do they have 110V to ground?

USA has pretty much the same as us except the voltage is halved i.e. 115v betewen live and neutral and live and ground.

They do also have what they call a "single phase" supply and that is 2 legs of 115v and E not what I would refer to as single phase at all.

 

They do run a lot of heavy current stuff like air conditioners cookers etc at 208v which is where this " single phase" system comes in to use.

 

 

Julian