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DIY Forum >> Electrical Questions >> Electric supply to caravan https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1238928971 Message started by kamog on Apr 5th, 2009, 11:56am |
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Title: Electric supply to caravan Post by kamog on Apr 5th, 2009, 11:56am I would like to connect my touring caravan to the house mains when it is parked close to the house. The hook-up cable would run along concrete at the base of a wall and would not be a trip hazard. Questions I would appreciate guidance on: Is it ok to use waterproof 13a socket or would c-form be better? Should there be a switch outside? Should the socket be in a locked box to prevent children fiddling with a separate switch outside the box? Or would it be simpler to look for a waterproof socket with its own switch which traps the plug when on and releases the plug only when off? Is there a minimum height to mount the connection point? The caravan has its own CU inside with rcd and mcb protection but the power will in any case come from an rcbo in the house CU with nothing else connected to it. |
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Title: Re: Electric supply to caravan Post by CWatters on Apr 5th, 2009, 5:28pm While you wait for an expert to respond.. I have a power point in my garden that was installed when our house was built. Intended for electric mower etc. It's just an MK waterproof socket from this range. The lid closes around the plug so waterproof when plugged in. http://www.tlc-direct.co.uk/Main_Index/Wiring_Accessories_Menu_Index/Weatherproof_Accessories_Index/Wproof_MK_All/index.html Mine connects to the CU in the house by an armoured cable. The size of which would depend on length and loading. This would be notifiable under Part P of the Building Regs so you should either use a Part P Electrician or involve Building Control if you DIY. |
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Title: Re: Electric supply to caravan Post by CWatters on Apr 5th, 2009, 5:39pm Did some googling and found this guide for caravan parks... http://www.tlc-direct.co.uk/Book/7.9.3.htm |
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Title: Re: Electric supply to caravan Post by dingbat on Apr 6th, 2009, 12:49pm CWatters wrote on Apr 5th, 2009, 5:39pm:
That's Sixteenth Edition |
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Title: Re: Electric supply to caravan Post by Lectrician on Apr 6th, 2009, 3:43pm By the sounds of it you are going to be placing an outlet on the wall of your house, and trailing the cable to the caravan. I see no problems with this. There is no requirement to lock off the outlet or to have it switched, it is upto you if you want to add these features. You need to consider your earthing arrangements as a PME supply is not permitted to be used with a caravan hookup point. You may need to convert the earthing system for this circuit to a TT system. To comply to the regs regarding caravan hookups you would need to provide an MCB and an RCD (or an RCBO) for just purely this one outlet. The outlet should be mounted between 0.5 and 1.5 meter. I am *pretty* sure the maximum length of the hookup lead is 20m, and so the hookup point should be within 20m of the caravan. TBH, in a situation at home I would want it ALOT closer! Especially if you intend on leaving it connected for some time. To comply to the regs with regards caravan hookups, you should be using a 16amp cee-form type outlet and not a 13amp socket. In saying all this, I am sure most caravan owners have a 13amp plug to 16amp appliance coupler in their box of bits, and use this to power the caravan from a convenient socket at home. All the above regulatory precautions being thrown to the wind! As a matter of point, if you where to fit a standard MK Masterseal type 13amp socket, it could be positioned at any reasonable height, could form part of another circuit and be part of a PME system. The only requirement would be the RCD. I am not saying that this is suitable or safe to be used with a caravan ;) |
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Title: Re: Electric supply to caravan Post by Y3 on Apr 7th, 2009, 4:55pm dingbat wrote on Apr 6th, 2009, 12:49pm:
LOL, hey Ding! |
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Title: Re: Electric supply to caravan Post by Y3 on Apr 7th, 2009, 5:07pm Lectrician wrote on Apr 6th, 2009, 3:43pm:
Im just saying here, so dont get angry Lec ;) Its still a caravan made of metal, which would be earthed through the circuit supplying the MK masterseal on a PME supply. If the PME lost its neutral, the caravan's metal frame work and body would still rise to a dangerous potential? So wouldn't you still class the MK socket as a caravan hook up point, if the caravan is being connected to it? Would you not also TT the earthing arrangement under those circumstances? I take regard what you say at the end about it being suitable and safe by the way ;) Just thought I would mention what I was thinking, thats all. |
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Title: Re: Electric supply to caravan Post by Lectrician on Apr 7th, 2009, 7:42pm Thats why I gave two examples and pointed out the second example is not suitable - I was comparing. |
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Title: Re: Electric supply to caravan Post by kamog on Apr 8th, 2009, 6:30am Many thanks to all for the info. I am keen that best practice be used and I see PME label on pole supplying overhead to house and that E and N enter same jb close to meter. Am I right in thinking this means the earth conductor in the cable feeding the cee-form socket just needs to be terminated so it can't touch anything at the back of the socket while the eath pin in the cee-form should be connected to a local earth rod put through the concrete hardstanding? To get to unconcreted ground would require a complicated route along and through walls - in conduit to avoid mechanical damage. The nearest unconcreted ground is 25 ft away but it's under nieghbour's giant leyladii trees and so dry nothing else grows. To get to normal damp ground would require the conduit to run another 25 ft very conspicously along more wall and across concrete steps to get to a flower border. so would it be ok to put rod through the concrete and how long should it be? |
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Title: Re: Electric supply to caravan Post by Lectrician on Apr 8th, 2009, 10:43am Yes, drill a hole through concrete, drive a rod down. Test the rod to ensure you have less than a 200ohm impedance (using an earth loop meter is quicker than using an earth rod tester, and you are more likely to be able to borrow or hire an earth loop meter. If the impedance is greater than 200ohm, drive the rod further, adding extra lengths of the threaded rod as you go. 200ohm has no mathmatical reference to the 30mA RCD or touch voltages, it just the figure used to assume an earth rod is 'stable'. |
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Title: Re: Electric supply to caravan Post by kamog on May 19th, 2009, 5:59am Thanks again for info. Have bought earth rod but not yet done job. In meantime I have noticed other people's earth rods in towns mainly by front door. Almost all have no cover and look old and decrepit. One which looks newish had a black plastic box-like cover with permanent manufacturers wording about safety and electricity and not to interfere. Is this a requirement now? Place I got rod say they dont have covers. |
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Title: Re: Electric supply to caravan Post by Lectrician on May 19th, 2009, 6:39am The rods termination needs protection against damage, which is why you use the covers. There are two types, pits and covers. Pits flush into the ground, and a cover sits on top. They are available from all wholesalers. The rods you see in the towns are most likely redundant from the days where the electricity suppliers would not provide an earth. Although I do expect some of the installs are still relying on the decrepid rotting rods, and the owners just have no clue. Screwfix do a plastic pit: Click Me TLC do a plastic cover: Click Me |
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Title: Re: Electric supply to caravan Post by Y3 on May 21st, 2009, 8:09pm Lectrician wrote on Apr 8th, 2009, 10:43am:
how do you do this without ruining the thread, like i have done already? |
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Title: Re: Electric supply to caravan Post by Zambezi on May 22nd, 2009, 9:04am wrote on May 21st, 2009, 8:09pm:
I have not tried it with an earth rod but we always used to put a nut on the end of the rod, so you are hammering the nut rather than the rod. |
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Title: Re: Electric supply to caravan Post by Y3 on May 22nd, 2009, 7:11pm Yeah, I suppose. The rods come with brass couplers and i did think about screwing that on but thought that would be ruined too, its only soft metal compared to steel. |
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Title: Re: Electric supply to caravan Post by Lectrician on May 22nd, 2009, 8:28pm With rods that are designed to be added to by threading a second or third one to it, you get 'driving caps' which are screwed on when you hammer the rod in. I am not a fan of rods - I prefer earth tapes, taking the form of hard drawn bare copper conductors buried in a trench. Not often used by sparks unless they have trenches open already. The DNO use them all the time - they never use rods. |
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Title: Re: Electric supply to caravan Post by Y3 on May 22nd, 2009, 8:58pm Lectrician wrote on May 22nd, 2009, 8:28pm:
Cant see that being in the company I work for's pricing system, imagine that... ok love, im just going to dig a f***ing great trench just by your back door, mind your step as you go out there hey! Rods aren't great, but I will remember to ask for a cap next time I order some though, cheers Lec ;) |
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Title: Re: Electric supply to caravan Post by Lectrician on May 22nd, 2009, 9:39pm I wouldn't be digging a trench for a domestic.....but then given the options, I wouldn't use a rod at all. I have installed 'tapes' when tying down gensets. You need a good reliable and stable earth connection in this sort of situation. |
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