Caravan CU

[ban-all-sheds]

Yes the light switches are in the neutral and what difference does that make,

None at all until someone changes a lamp with the switch off, thinking that the lampholder will be dead.

There is still a fuse in the circuit protecting against overload.

But not against a L/E fault.

There is still a fuse in circuit, the fact that it is in the neutral is unlikely to affect its ability to protect against an overload.

It will do nothing for a L/E fault.

The only difference will be that the 13A socket's switch will be in the neutral

That's not the only difference.

All fuses downstream of the socket will be in the neutral.

 

[SUNRAY]

Yes the light switches are in the neutral and what difference does that make,

None at all until someone changes a lamp with the switch off, thinking that the lampholder will be dead.

All the books and other safety advice say switch off at the mains before changing a bulb.
Problem gone away.

There is still a fuse in the circuit protecting against overload.

But not against a L/E fault.

There is still a fuse in circuit, the fact that it is in the neutral is unlikely to affect its ability to protect against an overload.

It will do nothing for a L/E fault.

Fuses are there to protect against over current, not the L/E faults you refer to twice, thats what the RCD is there to protect against. The fact that the fuse can help is a nice benefit.
In this thread the OP is asking about using double pole MCB's to improve the safety if a polarity reversal happens.

The only difference will be that the 13A socket's switch will be in the neutral

That's not the only difference.

All fuses downstream of the socket will be in the neutral.

Any fuse fitted in either live conductor will perform its intended task.

Probably more than half the items plugged into the caravan will not have any fuses fitted, so that removes half of any such problems and the 16A MCB is more likely to go before a 13A fuse so that gets rid of half of whats left.



I will suggest again that the OP could if he wished wire the caravan to a continental standard instead of British and it will comply here too, the 13A plugs and sockets would then be replaced with reversible connectors without a fuse and most likely unswitched and they will too be fully compliant here. That would remove all of the objections raised in this thread.

 

[ban-all-sheds]

All the books and other safety advice say switch off at the mains before changing a bulb.
Problem gone away.

All the books and other safety advice say don't cross the central reservation on a motorway.

Just think of the money we could save by not having all that Armco - you should write to the Govt and tell them that as all the books and other safety advice tell people to stay on their side of the road the problem has gone away.

Fuses are there to protect against over current, not the L/E faults you refer to twice, thats what the RCD is there to protect against.

Really?

Blimey - think of all the time people have wasted measuring fault loop impedances.

Any fuse fitted in either live conductor will perform its intended task.

Probably more than half the items plugged into the caravan will not have any fuses fitted, so that removes half of any such problems and the 16A MCB is more likely to go before a 13A fuse so that gets rid of half of whats left.

There's just no point trying any more with you, is there.

 

[SUNRAY]

All the books and other safety advice say switch off at the mains before changing a bulb.
Problem gone away.

All the books and other safety advice say don't cross the central reservation on a motorway.

Just think of the money we could save by not having all that Armco - you should write to the Govt and tell them that as all the books and other safety advice tell people to stay on their side of the road the problem has gone away.

Fuses are there to protect against over current, not the L/E faults you refer to twice, thats what the RCD is there to protect against.

Really?

Blimey - think of all the time people have wasted measuring fault loop impedances.

Any fuse fitted in either live conductor will perform its intended task.

Probably more than half the items plugged into the caravan will not have any fuses fitted, so that removes half of any such problems and the 16A MCB is more likely to go before a 13A fuse so that gets rid of half of whats left.

There's just no point trying any more with you, is there.

I don't have a copy of the Regs in front of me but I have it in the back of my mind that caravans should have double pole switching on everything.

BTW when caravan parks first provided mains hook-up, the standard inlet connector was indeed a reversible Shuko, I dare say if I dig deep enough I may still have one of the connectors, I tended to stock them as I replaced a few when they got broken by driving off still plugged in.

Personally I would use double pole switching in a caravan or any other situation where DP MCB's are used whether its regs or not.

So heres a simple question.

Have I made any false claims or statements in this thread?

I'm not saying I'm happy with all of it, however I believe it to be factual. I'm always happy listen to others to be corrected.

 

[Lawbringer]

Thanks for all the replies, it's been an interesting read. At some point i'll study it very carefully and make a call on what to do.

For this year, mostly because i've run out of money to spend on the damn thing i'm just going to wire it up internally to a household 13Amp RCD and take a extention lead off that. We will not be using the 'van abroad this year.

It will probably mostly be used for a kettle/toaster/heater (not at the same time) and a small inverter to run the couple of 12V lights that were installed.

 

[LoveRocket]

Thanks for all the replies, it's been an interesting read. At some point i'll study it very carefully and make a call on what to do.

For this year, mostly because i've run out of money to spend on the damn thing i'm just going to wire it up internally to a household 13Amp RCD and take a extention lead off that. We will not be using the 'van abroad this year.

It will probably mostly be used for a kettle/toaster/heater (not at the same time) and a small inverter to run the couple of 12V lights that were installed.

Ignore Banal, listen to Sunray.

Why not crack on and do it properly? We're not talking a huge amount of cash here - probably a tank of fuel for whatever you use to pull the thing!

 

[Lectrician]

I agree, the parts are going to cost very little on top of your bodge.

 

[SUNRAY]

Thanks for all the replies, it's been an interesting read. At some point i'll study it very carefully and make a call on what to do.

For this year, mostly because i've run out of money to spend on the damn thing i'm just going to wire it up internally to a household 13Amp RCD and take a extention lead off that. We will not be using the 'van abroad this year.

It will probably mostly be used for a kettle/toaster/heater (not at the same time) and a small inverter to run the couple of 12V lights that were installed.

Ignore Banal, listen to Sunray.

Why not crack on and do it properly? We're not talking a huge amount of cash here - probably a tank of fuel for whatever you use to pull the thing!

Thanks LR I was beginning to doubt my thoughts.

 

[ericmark]

Caravan consumer units can be found with simple google I have also seen the type with a neon and change over push button so easy to correct when the polarity is wrong.

I suppose we argue that the regulations only say it has to have an RCD and since most caravans have 12 volt lighting a single RCD is all that is required. However in same was as we don't trust the caravan site to have RCD protection neither do I trust them to have overload protection so I would fit a MCB or RBCO at most likely 10A so mine trips before camp site does.

I have seen so many caravans with 6A and 16A MCB's in parallel and they have been plugged into a supply using a 6A MCB and even where a 16A is used for supply the caravan MCB's we know will never trip.

I considered one of the motor overloads so one could vary to tripping current to match site until I found out the price.

This brings one to the question is there any real need for twin pole MCB's? I realise out of UK you can get the line and neutral swapped but I think I would prefer to have a Martindale tester than use twin pole MCB as we don't have MCB's inside any equipment we just have a fuse so drop knife into toaster and if fuse blows first it could be live so mush safer to ensure power is correctly connected.

So double pole RCD of course but with martindale plug in tester left in one plug hole I see no reason to use twin pole MCB's I would be happy to use single pole. However as already said I would want some form of indication if polarity is wrong so at £42.50 is it really worth messing around why not by one made for the job? Complete with neon to check polarity.

 

[Lawbringer]

Eric, I did do a few searchs regarding caravan CU's but didn't find much. Anything I did find was, well... very expensive. if you could point out a couple you've found I'd be greatful.

The Van was supposed to be a cheap get away so far we could have had two weeks in Greece and spending money for what i've spend. I'll invest more but probably not till a later date.