Shore Power - Is this safe?

prv said:
Most of the earthed types of European plugs are in fact polarised, with the exception of the German Schuko that uses the contacts on the side instead of a pin.

The unearthed one-size-fits-all Europlug is of course unpolarised and could be either way round, but appliances using it also have to be double-insulated - if they were in the UK they'd be allowed to use a plastic "earth" pin just to open the shutters (though many are in fact metal anyway and simply not connected). The Europlug is also limited to 2.5 amps because, having flexible pins to accommodate varying socket types, it might not make a firm enough contact to carry higher currents.

Pete
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On of the worst plugs and sockets ever is the earthed EU round plug .... where you have metal sprung tabs at sides to earth ... So many of them end up with distorted tabs that you cannot then get plug in.
The other of course is the EU extension - where you have red 'tabs' that need to move out of way to let pins insert. You see people banging ... wriggling ... swearing at ... just trying to get that pesky plug in !! So much so that many people open the box and rip the red tabs out !!

To anyone interested ... when looking at an EU socket .... according to info I received from company that has local authority and Port Terminal electrical installation contracts here in Ventspils, Latvia .... the EU socket Phase or what we laughingly called +ve before - is the connection on the right when looking at the front of socket ... Great. But who remembers when its a two pin plug in which way you like ???

I know some don't like the UK plugs etc. - but at least its pretty universal in UK and everyone in UK understands it. But in EU land ... UGH !! its a b*****y mess.

Lets take the humble two pin plug ... you'd think that would fit all two pin sockets here ? No it doesn't. Eve what I call the shaver plug can be slim pin, fat pin, too wide, too close together. The two p[in socket can be slim, round, with tabs, without tabs. You cannot put a two pin into a 3 pin socket ... its b****y murder !

I'm sitting at a desk that has 3 different adaptor extensions to cater for gear .... for that daft reason.

Sorry to go off the topic ... had to get that off my chest !!
 
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PaulRainbow said:
As is becoming all too common on PBO electrical threads, too much thread drift and waffling is confusing a simple question. I answered the OP's question in post #21, let's hope the rest of the thread hasn't caused the OP even more confusion.

Quite agree. Loads of waffle that have nothing to do with the original question. I quite agree with you previous comments. Something not right with the OP's description as one or another RCD would trip, if as described. Even with an isolating transformer it doesn't make sense. I won't offer an opinion as not having seen the installation I think that any opinion expressed on an unseen mains (240v) system could be misleading and dangerous. If he is not sure of what has been installed and lacks knowledge of electrics in general, I would strongly suggest he consults a professional.
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prv said:
Most of the earthed types of European plugs are in fact polarised, with the exception of the German Schuko that uses the contacts on the side instead of a pin.
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As I understand it, systems like the French one are polarised in theory, but in practice there is no consistency in wiring, so assuming a particular polarity is unsafe. French RCDs disconnect both wires for this reason.

I found this at www.toughleads.co.uk:

cdd4jl6.png
 
Refueler said:
I was dead against radial for simple reason .... and any good electrician will back this up ..... radial means that accumulated power requirement into a single cable end, instead of a ring where it divides.
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Since most of the world looks on ring mains with suspicion, you might have to refine your definition of "any good electrician" a bit. Ring mains were originally introduced to save copper, at the cost of far more complicated safety checks and significantly higher risks. Every 13A double socket in my house is fed directly from the CU by a 32A cable. Much easier, much safer and the cost of slightly thicker wire was lost in the noise.
 
JumbleDuck said:
Since most of the world looks on ring mains with suspicion, you might have to refine your definition of "any good electrician" a bit. Ring mains were originally introduced to save copper, at the cost of far more complicated safety checks and significantly higher risks. Every 13A double socket in my house is fed directly from the CU by a 32A cable. Much easier, much safer and the cost of slightly thicker wire was lost in the noise.
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I accept that I cannot speak to all electricians ... but all the ones I have - all agree that the dividing of the load is better.

Your 32A cable is great ... but how many sockets down the line before the end ? That's the point. The initial part of the cable is carrying the load for all the sockets in a line ... you only need a few items plugged in and that 32A can soon be at limits.
 
BabaYaga said:
Apologies for waffling on about the ISO 13297, but it does require the RCDs used onboard boats to be double pole. Hopefully this is also the case on boats in the UK.
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I insist on double pole in the house as well ... having once had a 'jolt' from an EU standard light socket because of the single pole breaker ... I am not in the mood to repeat !!
 
I am sure that ring mains and radials together with continental sockets and wiring are of consummate and riveting interest to both academics and dinner parties world wide. However, what do they have to do with the price of tea in China. Or indeed, earth/ neutral connections on boats?
 
Alex_Blackwood said:
I am sure that ring mains and radials together with continental sockets and wiring are of consummate and riveting interest to both academics and dinner parties world wide. However, what do they have to do with the price of tea in China. Or indeed, earth/ neutral connections on boats?
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Look out Forum Police on the prowl ...

In fact if you consider the wiring aspect of EU vs USA vs UK ... they can have a very big impact on the OP's connecting of Neutral / Earth / DC etc.

But like every other forum ... once a topic gets answered - they often divert on to paths that have connection but are unnecessary.

If its not to your liking ... then 'scroll on by' .....
 
Refueler said:
I accept that I cannot speak to all electricians ... but all the ones I have - all agree that the dividing of the load is better.

Your 32A cable is great ... but how many sockets down the line before the end ? That's the point. The initial part of the cable is carrying the load for all the sockets in a line ... you only need a few items plugged in and that 32A can soon be at limits.
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Apologies for contributing to the irrelevant waffle, but this needs answering.

The 32a cable will be connected to a 32a circuit breaker, so it can carry up to its rated current without tripping the breaker, but if it's overloaded, the breaker will trip. The initial part of the cable will be carrying all of the load, irrespective of where along the cable the load is plugged in.

The point with a properly planned radial circuit is that all parts of the circuit are rated for expected loads. The cable rating and breaker rating both need to be matched.

If there was a fault part way along the cable, the outlets before the break would all work as normal and would all still be correctly protected by the appropriately rated circuit breaker. Those after the break would not work and you'd need to get your sparky in.

A ring main, usually wired with 2.5mm cable will also have a 32a circuit breaker. As 2.5mm cable has a current rating of around 17-20a (depending where it is installed) the 32a breaker will trip if the circuit is overloaded.

Now, if there is a fault somewhere on the ring, all of the sockets will continue to work. But, you now have cable rated at 17-20a, protected by a 32a circuit breaker.

It's also possible to overload parts of a ring circuit if the circuit isn't balanced.

There are no good reasons for using ring mains, other than a small cost saving (debatable if that's a good reason).

UK reg's allow for radial circuits, boats are usually wired with radial circuits.
 
Refueler said:
Look out Forum Police on the prowl ...

In fact if you consider the wiring aspect of EU vs USA vs UK ... they can have a very big impact on the OP's connecting of Neutral / Earth / DC etc.

But like every other forum ... once a topic gets answered - they often divert on to paths that have connection but are unnecessary.

If its not to your liking ... then 'scroll on by' .....
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Totally irrelevant to the OPs question. No installation can support earth and neutral being connected together after a RCD
 
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Hi PR ... risking Hell and Damnation ...

I agree with your post about the differences ... EXCEPT the fact Ring Main ends up with higher cost because of the extra 'tails' back to the Consumer breaker unit.
If the RM does break - it would still have the breaker as you have and as most people now have RCD and not old fashioned fuses ...
 
Refueler said:
Hi PR ... risking Hell and Damnation ...

I agree with your post about the differences ... EXCEPT the fact Ring Main ends up with higher cost because of the extra 'tails' back to the Consumer breaker unit.
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There will usually be more cable in a radial system and the cable will all be thicker, so the radial system will cost a little more.

If the RM does break - it would still have the breaker as you have and as most people now have RCD and not old fashioned fuses ...
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If there is a break in the ring circuit you lose the cable paralleling, so every outlet is now supplied with a single run of 17-20a cable, but the breaker is rated at 32a.

The RCD is irrelevant, it doesn't protect against overloads.
 
pvb said:
This is untrue - RCDs offer no protection against overloads.
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I know that ... but if the overload causes cable to fail insulation and short ... which dear PR is getting to with his 17-20A cable on a Ring Main ... which I dispute as in the houses I had in UK rewired ... and here in Latvia ... NO-one used such piddly cable ..
 
Refueler said:
I know that ... but if the overload causes cable to fail insulation and short ... which dear PR is getting to with his 17-20A cable on a Ring Main ... which I dispute as in the houses I had in UK rewired ... and here in Latvia ... NO-one used such piddly cable ..
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So, what cable do you think your ring main was wired with ?
 
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