Query on Protective Multiple Earth

[andy_b]

Hi

I have a question with regards to connecting two different earthing systems.

I am on a vessel which has a switchboard set up that is TN-C, combined neutral earth, this is supplied by onboard gensets, 3 Phase 380V 50 Hz.

With regulations as they are all boatyards/docks are set up with a sperate earth and neutral supply for the vessels docking there.

So I need to supply the vessel with shore power while both generators are shut down for Maintenance, therefore connecting a seperate earth neutral supply to a combined earth demand.

Obviously if the combined earth neutral from the vessel is taken directly to the vessel then it causes the power supply to trip.

I was wondering if ther was any safe way to connect these two systems without leaving risks of high fault currents.

Is it possible to bond the earth to the hull of the vessel as this is steel and take the combined leg directly to the neutral? Or is there any way to combine the neutral/earth supply before it reaches the vessels switchboard?

Or are there any products that can be used to help make the link up possible?

Thanks for any advice

Andy

 

[Spudnik]

Moved to general forum

 

[patricklondon]

morning andy and welcome to the forum. i'm sorry but this is beyond my range of experience, hopefully one of the others here can give you the answer you need. good luck

 

[Guest123]

Hi.

Cant really get me head round this at the minute....I'll have a bit more of a think and check in later.

 

[andy_b]

Thanks guys, any advice or pointers are appreciated!!

 

[xraytek]

Not my area of experience at all but wonder if the solution was to install an isolating transformer on the boat for the yard supply to connect to, then connect the boat to the output of the transformer?

 

[ghost]

I must say this something I have not studied before.
I did a bit of web trawl and came up with this, it seems quite technical and may help you with the info you need.

http://www.portgot.se/prod/hamnen/g...g_NorthSea.pdf/$file/Coldironing_NorthSea.pdf