Shore Ground NOT Connected to Isolation Transformer

[goboatingnow]

Originally Posted by Lake-Effect

Thank you. I respect your opinion. And that you have acknowledged that grounding does offer enhanced safety, but that you consider the benefits of this are so small as to be outweighed by the other considerations, like potential galvanic corrosion. Good stuff. Useful. Complete.

"Oh Lo-ord it's hard to be humble..."

Most independent experts manage to offer useful information and advice without being absolutist about it, claiming superior authority, or slagging the dominant standards bodies. And making some mistakes, while inferring their infallability. Just sayin.

ISO is the dominant standards body even now ABYC is essentially homologating it’s new standards to ISO. this is necessarily a great thing in my view as ABYCs thinking is now an influence in ISO.

[Lake-Effect]

Originally Posted by goboatingnow

From ISO 13297

3.8
isolation transformer
transformer installed in the shore power supply circuit on a craft to electrically isolate all the normally live conductors (3.11) and the protective conductor (3.10) on the craft from the AC system conductors of the shore power supply

Thank you.

[Lake-Effect]

Originally Posted by s/v Jedi

I call the diagram that I posted authoritative not because I made it but because it is the preferred setup worldwide. Even in the US where the big installers all say “yes, ABYC” and proceed to install Victron isolation transformers like in this diagram. And for good reason!

It is an option. Arguably the best option for fiberglass pleasure boats, especially in ISO countries, maybe less so in N America at the moment. And what about aluminum or steel hulls?

One should be a bit more restrained about calling something "authoritative", at least without all the caveats.

Originally Posted by goboatingnow

Once you have a discontinuous( isolated) ground , seawater simply cannot become a fault return except under bizarre conditions requiring multiple faults simultaneously

As I said a continuous ground degrades onboard safety not enhances it. It inserts metal surfaces in contact with seawater into the fault return , whereas before these where not in that circuit with an isolated ground.

Three words: "marina", and "other boats".

Other than that, I still don't know what you're driving at there.

This has devolved into hair-splitting now; the main points and opinions are all in the thread, no sense rehashing them.

[goboatingnow]

Originally Posted by Lake-Effect

It is an option. Arguably the best option for fiberglass pleasure boats, especially in ISO countries, maybe less so in N America at the moment. And what about aluminum or steel hulls?

One should be a bit more restrained about calling something "authoritative", at least without all the caveats.



Three words: "marina", and "other boats".

Other than that, I still don't know what you're driving at there.

This has devolved into hair-splitting now; the main points and opinions are all in the thread, no sense rehashing them.

Unless your neighbour is baring live wires and throwing them on your deck I don’t see your point , if your neighbours boat is leaking into seawater then discontinuous ground actually helps protect you , whereas continuous ground makes your boat a conduit , to the detriment of all your underwater metals

It’s not hair splitting nick and I have long argued that ABYC has got this aspect wrong and continues to do so. As nick says you buy a victron and wire it as victron stipulate , as most in the US do , you get the ISO approved method. ( and I doubt any US insurer would quibble)

ABYC was wrong on ELCIs for years after ISO mandated them , belatedly accepting the rest of the world late in the day , it’s wrong about this too. ( ABYC is wrong about underwater bonding on GRP too but that’s another days argument )
Simples

[Lake-Effect]

I'm content to leave this alone.

[goboatingnow]

Originally Posted by Lake-Effect

I'm content to leave this alone.

By the way ABYC E-11 ( 2008) does not require continuous Earth. It does require the transformer case to be grounded to shore power , but that case is not then connected to ships ground.

Hence iso and abyc agree in this respect , earths are not connected, nicks diagram meets the salient aspects of the ABYC standard

[Lake-Effect]

Originally Posted by goboatingnow

By the way ABYC E-11 ( 2008) does not require continuous Earth. It does require the transformer case to be grounded to shore power , but that case is not then connected to ships ground.

Hence iso and abyc agree in this respect , earths are not connected, nicks diagram meets the salient aspects of the ABYC standard

And I've said as much, waay back. ABYC considers both methods acceptable.

(I think you'll find that ABYC requires the metal transformer case grounded to boat ground.)

[goboatingnow]

Originally Posted by Lake-Effect

And I've said as much, waay back. ABYC considers both methods acceptable.

(I think you'll find that ABYC requires the metal transformer case grounded to boat ground.)

No E-11 diagram 8 shows the case and shield only connected to shore earth not boat earth.

[Lake-Effect]

Originally Posted by goboatingnow

No E-11 diagram 8 shows the case and shield only connected to shore earth not boat earth.

Sorry, nope.

Think about it; on the boat, where the shorepower AC and ground are isolated from the rest of the boat, then the remaining source of shock hazard is the secondary side of the transformer.

[goboatingnow]

Originally Posted by Lake-Effect

Sorry, nope.

Think about it; on the boat, where the shorepower AC and ground are isolated from the rest of the boat, then the remaining source of shock hazard is the secondary side of the transformer.

See diagram 6 , stick the victron in a big plastic box. Disconnected grounds are ABYC ok.

[Lake-Effect]

Originally Posted by goboatingnow

Disconnected grounds are ABYC ok.

For the umpteenth time, we've already agreed on that. What IS your problem??

[goboatingnow]

Originally Posted by Lake-Effect

For the umpteenth time, we've already agreed on that. What IS your problem??

You , arguing connected grounds, were safer

[Lake-Effect]

Originally Posted by goboatingnow

You , arguing connected grounds, were safer

Ah... a warm sunset, a little retsina.... Someone's ready for bed, hmmm? Nite nite.

[CharlieJ]

GBN #98
I caution you against using a 14 year old document that is updated every year as a valid source of information.

[Pelagic]

Originally Posted by goboatingnow

Given here RCBOs are cheap I would always have one fitted right behind my shore power cable entry. If fitted this allows no shore earth to come in contact with an isolation transformer.

RCBOs can be less usefully fitted to the output side of the transformer as the existence of sneak return paths is virtually eliminated by taking earth ground out of the equation. But I’d still fit them anyway albeit they are less effective. MCBs of course should be fitted to the output side

So I switched over to a new 100ft Shore cable yesterday from my somewhat frayed old one..... this cable was spliced on to a 50ft extension by the Shipyard before plugging into the shore pedestal
AT THE SPLICE THE ELECTRICIAN HAD NOT CONNECTED THE GROUND WIRE ...Just L & N
Part of my querie on first post .

So I was planning on installing the new RCBO before the onboard Junction box and Isolation Transformer today.....

But does that do anything given the way the yard wired the splice??