Anodes+Galvanic isolator queery?

[Seanick]

If you just run a seperate lead from the pontoon to your dehumidifier, without involving your boats ring main, I would have thought that would keep your boat out of the circuit and your anodes intact.
Sure to be corrected if I am wrong, but a simple solution?

 

[VicS]

[ QUOTE ]
a simple solution

[/ QUOTE ] Yep a simple solution. Thats how anyone without a full shorepower installation would do it. Not got the protection of the mcb if you did it like that and youd want an RCD at your end as well.

Then youll want to leave the battery charger on some times.

I reckon if you've got a proper shorepower installation its worth fitting the GI. Job done . Always available to use when and for as long as required.

 

[Frontier]

[ QUOTE ]
How about a simple 240v contactor/timeclock in a waterproof box installed when leaving the boat in the shore line that when energised completely isolates (effectively unpluging) the boat say every 12hrs for as long as you like! About 1/6th the cost of an isolating transformer, which I suppose must be the best solution?


[/ QUOTE ]

I dont think its good parctice to have the earth on a switch, its a point of failure you dont want in the future.

I have a GI which has some LED's so if its ever working it shows and the fault can be investigated.

D

 

[misterg]

That's the way to do it for a dehumidifier.

With a battery charger, there might still be a connection between the DC wiring and the mains earth, so a GI would be required for peace of mind.

Assuming the OP is in the UK, the pontoon outlet will have an RCD (by law), so no need to provide one of your own.

Not keen on anything that switches the earth connection - Don't know if it is allowed under IEE regs, but in any case, it would have to be rated for the full fault current of the circuit (can be 100s of amps).

Andy

 

[VicS]

[ QUOTE ]
the pontoon outlet will have an RCD (by law), so no need to provide one of your own.


[/ QUOTE ] but can you be sure the pontoon one will operate.

Far better to have one of your own in your shorepower panel. You can then test it yourself at intervals and be confident about it.

[ QUOTE ]
With a battery charger, there might still be a connection between the DC wiring and the mains earth

[/ QUOTE ] The shorepower earth should be connected to the ships earth. In most cases that will also mean to the DC negative.
That's the current recommendation and in some cases I believe a requirement.
(Still looking for confirmation of that though!)

 

[misterg]

[ QUOTE ]
but can you be sure the pontoon one will operate.

[/ QUOTE ]

Not going to argue with you about it, but the pontoon one will be subject to regular tests (again by law), and I would be just as confident that it would trip as I would one of my own at the end of a shore power lead. (You're relying on the pontoon one to protect the whole shore-power lead, anyway).

[ QUOTE ]
The shorepower earth should be connected to the ships earth. In most cases that will also mean to the DC negative.
That's the current recommendation and in some cases I believe a requirement.
(Still looking for confirmation of that though!)

[/ QUOTE ]

Not quite the same point - If one were to plug the battery charger directly into a shore power lead to avoid galvanic corrosion, you would bypass the boat's distribution system and its associated interconnections - my point was that even with just the battery charger connected directly to a shore power lead, the DC output may well be connected back to mains earth via the charger itself. One would need to check.

As an aside, I think that the requirement for connecting shore power earth to DC -ve is an American requirement (AYBC????) some info here

Andy

 

[John100156]

Yes, I can quite understand the reluctance to take an earth through a set of contacts. Thats why I suggested it's only done when you leave the boat.

A socket has a 0.4 second dissconnect requirement and a luminaire 5s because it is generally considered out of reach. I have a copy of the latest 17th Edition - not sure if it covers marina's but will have a look.

I am sure an RCCBO or ELCB could protect the circuit to give added protection in the event of a disconnected earth.

Otherwise I suppose we are just left with the isolating transformer! The GI (as I have on my boat) still allows some leakage.....

 

[mightymouse]

lots of advice there.
My tub will not be stored in the water... only in and out on usage days..
So it's probably not required eh?
cheers
Location
Hastings
East Sussex
UK

 

[VicS]

[ QUOTE ]
My tub will not be stored in the water

[/ QUOTE ] Nope. Dont need galvanic isolator or anodes or antfouling if its not in the water.