mains/Shore power Failure Moody 44

[Richard10002]

Moody 44 - Mains AC power tripped pontoon Circuit Breaker ... reset but power not restored on board - Polarity light comes on if polarity is wrong, but no lights come on if polarity is reversed to correct it. This suggests that power is getting to the boat, but not to the main distribution board, apart from to chack the polarity - not sure how that works?

Thinking about it, and reading the manual, suggests that the RCCB has tripped, ( I may be wrong, and it could be a faulty circuit breaker on the distribution panel - and I think I should know where this RCCB thing is, in any event).

The manual says:

"it is somewhere between the input socket and the main distribution panel ... this is a 30mA type and will trip out if there is a voltage change between positive and negative anywhere in the boats 240V system after this unit"

The circuit diagram shows only the DC side of the system.....

I cant find it ..... any ideas??

Done a search on Residual and RCCB with no joy.

many Thanks

Richard

Also posted on Moody Owners

 

[VicS]

Not quite sure what tripped on the pontoon. Either the RCD (RCCB) which trips due to an earth leakage fault or the main circuit breaker which trips due to an overload, which itself could be a short to earth.

This statement:

"it is somewhere between the input socket and the main distribution panel ... this is a 30mA type and will trip out if there is a voltage change between positive and negative anywhere in the boats 240V system after this unit"


Does not entirely make sense but refers to your on board RCD (RCCB) which will trip if there is an imbalance of 30mA between the <u>current</u> in the <u>live</u> and <u>neutral</u> in the 240 volt system....

If it was just the RCD that tripped on the pontoon then I agree that it is the RCD (RCCB) that has tripped on your boat as well.

I would expect to find it possibly combined with an overload circuit breaker very close to the incoming shore power connection or even combined with it. Or as part of the distribution panel.

If not combined with the incoming connection follow the cable from there and it and the circuit breaker should be the first thing you come to. There will probably be just a small reset button next to a test button (that you should be using to test its operation periodically)

An overload or short could have tripped the overload protection circuit breaker.

I hope that makes sense. It does to me but only just!

 

[William_H]

Yes Vic that was a fine description. Just to add. Circuits have 2 kinds of protection the first being for excessive current. This was traditionally with a fuse but often now by a circuit breaker. This operates at a specific current like 15 amps and is there to protect the wiring which with excessive current can burn.

The second more recent protection RCCD is for reduction of risk of electric shock to people. It is based on the concept that most shocks come from faulty equipment where the person contacts a live wire (active) or part while also contacting anything conected to earth. ie water, metal cabinets of fridge sink etc. The theory is that current will flow from active through the person to ground wheras normal current flows from the active to the neautral wire. The device detects current flowing in the active which is not exactly reflected in the neutral. The difference is typically 30 milliamps. (30 /1000 amp) This current through a person is survivable while any more may not be.
Unfortunately the RCCD is so sensitive that it will often operate with equipment that does not have perfect insulation. Hence inconvenient power interuptions.
So you are looking for 2 kinds of protection which can cause the failure. Or it may be poor contacts on a switch or wire connection.
essentially if you can't identify a CB or RCCD that has operated or failed then you have to follow the current progression with a meter which can be difficult/ dangerous. ie perhaps you need a proffessional. good luck olewill

 

[chasroberts]

Suggest you switch off/unplug everything on the 240 system. Connect the shore power. If it trips the shore circuit breaker then your problem is in the 240system between the shore and boat board.
If it does not trip then slowly start turning things on and off one at a time until you find what is causing the trip. Could be something like a faulty kettle element etc. Usually just a matter of trial and error.
One other thing. After heavy rain the shore power connection plug used to get a little water ingress. This would always cause the shore power to trip. Dry out/replace plug interior sorts this out.
Hopefully it will be something simple like this.

Good Luck.

 

[jimbaerselman]

You've been there before Chas! So have I. Your approach is exactly right, though on some vessels it's not always easy to unplug/switch everything off! My problem was a slightly corroded immersion heater . . . whose circuit breaker (the sole switch) was fitted by the tank. I wasn't even aware we had an immersion heater until then!

 

[Nick_Pam]

Richard

If I read your note correctly, you are looking for a circuit-breaker which on my Jeanneau looks like a weatherproof box with a switch in it, and is located at the point where the boat-end of the shore-power cable goes into the IEC socket.

Feed from there goes to main distribution panel etc etc.

Mine has tripped once following a pontoon trip-out in Port Camargue (they have a very flaky pseudo 16amp supply which regularly trips at about 9 amps!!) last summer.

Good hunting!!!

Nick

 

[Richard10002]

[ QUOTE ]
Richard

If I read your note correctly, you are looking for a circuit-breaker which on my Jeanneau looks like a weatherproof box with a switch in it, and is located at the point where the boat-end of the shore-power cable goes into the IEC socket.

Feed from there goes to main distribution panel etc etc.


[/ QUOTE ]

Correct - there seem to be 2 circuit breakers - the obvious one on the panel, and the one I cant find. I'll see what turns up and report back.

To the previous posts - with all services turned off at the dist'n panel, there is no shore power reaching the panel, so am not in a position to turn stuff on to create the trip and isolate the problem.

Thanks for the help so far

Richard

 

[Richard10002]

Nothing more sinister than a loose connection in one of the power cables, (the one which is attached to the boat, so is always used.

It seems that this second breaker probably doesnt exist ... I cant find it, my father couldnt find it when he owned the boat, and there is a note in the manual to the effect that a previous owner also couldnt find it.

 

[Anonymous]

Glad you're sorted out, Richard. It would be worth fitting an RCCB when you get settled for the winter. The techniques for fitting are no different to house wiring. Ours has done valuable service each time the water heater element fails, shorting it to earth - a very common problem - and the breaker trips when the fault current is around 30mA (30 thousandths of an Amp) instead of around 25A which would otherwise be the case /forums/images/graemlins/shocked.gif

 

[Richard10002]

[ QUOTE ]
Glad you're sorted out, Richard. It would be worth fitting an RCCB when you get settled for the winter.

[/ QUOTE ]

Hi David,

The switch on the panel is an RCCB - 25A - 0.03A, so that side of things is OK.

It's the other thing referred to in the manual which nobody has ever found - the manual suggests that it trips when the current on board changes from +ve to -ve, i.e. the polarity changes.

having discussed it on the Moody Forum, it seems that nobody has one of these so maybe the RCCB which I have covers all events.

Cheers

Richard

 

[Anonymous]

It's worth being pedantic or there is a risk of confusion. The terms 'polarity', + and - are used in dc circuits. We talk about Line (L), Neutral (N) and Earth (E) in mains circuits. It is possible to wire a panel to protect against someone wiring the L to the N (or either of those to E). There is more than one way to do that and usually you get an alarm or a light which may or may not tell you exactly what the problem is - it might just tell you there is a problem and you have to find it.

On the Nauticat, there are quite a few things in the manual that are not actually wired into the boat. The terminals are there but it hasn't been fitted (windscreen defrosters, for example, which presumably are only fitted for very cold climates). Or it might be that a previous owner had trouble with the sensing system and took it out.

Knowing that electricity isn't your forte, when you get to your winter home, it might pay you to find someone who is or was an electrical engineer, technician or electrician and see if they will check out all the mains stuff for you. There are some special instruments used in the trade which can check for things you simply cannot check for with an ordinary multimeter. A competent person should be able to check it out in much less than a morning unless there are problems, of course.

 

[Richard10002]

No problem with pedantic - it often gets to the root of the problem and helps with understanding.

There are a set of 3 lights by the RCCB which confirm that AC is available/on/correct polarity. In pedantic terminology, I guess the polarity light means that L & N are reversed where the power comes in. When this happens, (often in Europe), I have a short cable which reverses L & N.

I had all the electrics checked and some work done by the electrician at Glasson Dock ... he was quite happy with it all, and I learned a reasonable amount about it to get by.

Certainly worth getting someone to eliminate the confusion over what the manual says, and what actually exists.

 

[Anonymous]

I agree with all of that. I am astonished that you have experienced reverse wiring often enough to justify making up a freak cable. But then I don't have any sort of monitoring system and never check, so who knows how often it has happened to me?

 

[Richard10002]

I wouldnt know if I didnt have the little light - everything works just the same, although I'm sure the shock hazard is increased.

I also have a Rapitest 13 amp socket tester which has 3 lights the sequence of which tell you what is wrong, or that all is OK. One of these would tell you how things are.

 

[Anonymous]

[ QUOTE ]
I also have a Rapitest 13 amp socket tester which has 3 lights the sequence of which tell you what is wrong, or that all is OK. One of these would tell you how things are.

[/ QUOTE ] Thanks, Richard. Do you think that they would work with continental sockets? /forums/images/graemlins/wink.gif

 

[Richard10002]

[ QUOTE ]
Thanks, Richard. Do you think that they would work with continental sockets? /forums/images/graemlins/wink.gif

[/ QUOTE ]

It's basically a 3 pin plug with some lights and a diagnostic diagram on the back, so it wouldnt work with 2 pin sockets.

Having said that, I'm guessing that if the boat has continental sockets, you will have some plugs which convert them to accept UK plugs - if so, plugging it into one of these should work.... if that makes sense <g>

 

[Anonymous]

Just so long as the British kit will understand electrons all speaking Euro-babble /forums/images/graemlins/smile.gif