PaulRainbow
Well-Known Member
For heavens sake, read what i've said in the thread. In particular post #17
Recommended current leakage in mA for RCBO on boat?
- Thread starter Vega1447
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For heavens sake, read what i've said in the thread. In particular post #17
VicS
Well-Known Member
The point is though that the supply must not be a TNCS system
The supply to marina buildings may be but the supply to the pontoons must not be.
PaulRainbow
Well-Known Member
You're just digging now.
Post #17 says "Marina shore power systems are required to have double pole Earth leakage protection and the neutral must be bonded to Earth at the pontoon. "
That is how it must be. There is no need to list any ways that it must not be. If a regulation says something has to be yellow it will not list all of the colours that it cannot be, it just says "Must be yellow".
Equally, there is no need for you to tell me "That is correct but its not that simple ". It is that simple, that's how it must be, nothing else is allowed. Simple.
VicS
Well-Known Member
How would you bond the neutral to earth at the pontoon if the supply is a TNCS system ... A TNCS system does not have a earth conductor, just line and a combined earth and neutral conductor.
You cant of cousre but the sitation does not arise because as I said earler in support of Channel Sailor an TNCS system is not allowed.
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PaulRainbow
Well-Known Member
Still arguing about what isn't allowed, therer are many things that are not allowed and only one that is, which i stated earlier, before you attempted to correct my already correct post.
Channel Sailor was talking about systems which were clearly not allowed, which i pointed out were incorrect. If it doesn't have N&E bonded, it isn't allowed.
End of story.
VicS
Well-Known Member
Why is this required in this situation ?
The neutral is earthed at source . Why does it also have to be bonded to the earth conductor at the pontoon?
.
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PaulRainbow
Well-Known Member
Lots of information on the internet, in various regulatory documents and in the current ISO (available to purchase online (i have purchased copy)).
VicS
Well-Known Member
I am sure there is but I am asking you via theses forums for a simple expiation.
Gumpy
Well-Known Member
Is the pontoon wiring covered by an ISO or is it covered by BS7671, I don't have the latest version as I have retired but it would surprise me if BS7671 didn't mandate how the pontoon should be wired and an ISO how the boat should be wired.
PaulRainbow
Well-Known Member
You are correct, BS covers the pontoon and new build boats need to conform to the standards in the ISO. The latest ISO covers DC and AC on the boat. I'm not involved with, or particularly concerned with, marina electrical installations, i am a marine electrician. Whilst i am under no obligation to adhere to the standards in the ISO, i think it's common sense and best practice to do so. It doesn't especially concern me if the marina have not complied with their particular regulatory requirements, because, if the boat is wired correctly the onboard electrical safety devices will protect the boat and its occupants regardless.
There have been illegal, pirated, copies of previous ISOs floating around the internet, which certain pedants and armchair experts have accessed, but no such version of the latest ones appear to exist. They seem reluctant to pay for a legitimate copy.
Alex_Blackwood
Well-Known Member
18th edition IET Regs. for Marinas. No where is the neutral bonded to earth except at the main TT Earthing point. Note PME protection is not permitted. The original question was "What is a suitable RCD" Answer: - 16 amp 30mA RCBO or 16 amp MCB and 30mA RCD!
PaulRainbow
Well-Known Member
Thanks for the kick in the memory Alex, it was the socket terminals being connected to Earth i'd misremembered as being connected to neutral.
But as you say, the original question was "Recommended current leakage in mA for RCBO on boat?"
This was answered more than once, but i did ask for some additional information, as it's no good fitting a single RCBO if there are circuits that require lesser current protection than the 16a RCBO would give.
Alex_Blackwood
Well-Known Member
Paul, Quite agree with your "Additional information" Very difficult to give answers to some of these queries as the actual installation may differ from the description! I often keep quite rather than give information which may be wrong or could be mis-interpreted and cause a accident.
Before anyone picks me up. I have made a cockup in my post. The Neutral is bonded at the supply end not the TT earth. It can be that the neutral is connected to the Earth where the main supply enters the Marina e.g. in a clubhouse. Anyway that's another kettle of fish!
PaulRainbow
Well-Known Member
Indeed! As i said earlier, i'm not concerned with the shore side of things and not really that interested, my job starts on the boat. If i do my bits correctly it doesn't matter if the marine part isn't entirely correct (within reason).
I sometimes think i should keep out of AC threads on here, as they always end up with someone causing an argument. I do find it difficult though, when the advice is bad.