Would it be acceptable?

[Fiat Ducato]

Hi just a quick question for discussion and looking for some advice on whether or not it would be acceptable to run a 3m length of 230v mains flex from the main consumer box through floor and the van and up through the floor again to under my seating, will then be fitted to a single gang DP socket. The flex will be enclosed in the plastic corrugated conduit you often see used.

 

It's my alternative choice as my first choice would be going through the floor internally along with several other 12v cables for water heater, truma vent, pump etc, put as the flex is quick thick it won't go through.

 

Obviously the socket will only be used when the vehicle is stationary and on EHP.

 

I have other 12v cables running under the van, from battery to battery charging etc, trigger wire from Ignition.

 

What are peoples views on this please, and keep it civilized folks ;-)

[Another1]

Can you give us some idea as to what you are going to use it for. Bringing 220v under your seat sound a little dangerous to me. If you wish to use it for charging or any other use is there not a safer place to put the socket. I have a 4 gang socket in the garage and is fitted very safely and used for charging, cooking and keeping beer cool in the cool box.

[Brian Kirby]

I assume by "acceptable" you mean would it comply with relevant regs? To answer that, you really need an electrician with access to the latest edition of the IET regs. I can't see why not, but I'm not an electrician and I don't have access to the regs. It's a radial circuit, which is permissible. It must be fused at the board with a fuse or MCB appropriate to the cable used. I assume you have a spare way off the board to which you can fit the appropriate fuse/MCB?

[Fiat Ducato]

Hi Brian

 

Basically I'm exchanging the short flex that came out of the consumer unit and went to my old 240v charger and 12v Power/distribution unit, which basically died and failed. And fit a longer flex cable instead in it's place and run it to the space under my seats.

 

I while ago I moved my leisure battery from it's original (stupid) mounting place on front rail under the radiator in the engine bay. Getting sprayed with water, covered in crud and dust from the environment, not to mention having to deal with the freezing cold.

 

I fitted my new leisure battery under the dining area seating, adequately fastened down with correct battery mount to the floor and the metal seating frame and vented through the floor with tube and also I added a floor vent for good measure.

 

I now want to run the mains lead up to the same area and fit a socket, so the new motorhome connect and forget mains charger can be plugged in and will then be powered on when connected to mains via EHP.

 

I understand that the Regs for mains in a motorhome state that a Double Pole socket must be used. I have checked the regs on the correct size of flex cable to use. Just unclear about having it running outside of van. Maybe the conduit as to be of a certain material and so as now mains flex is visable.

 

 

[aandy]

You don't say what sort of cable you plan to use, but I've been told by those who know (which I certainly don't when it comes to electrics) that vehicle applications should always use cable with a multi strand conductor, rather than the single core domestic stuff, as the latter is adversely affected by movement and vibration.

[Fiat Ducato]

Another1 - 2018-02-06 11:55 AM

 

Can you give us some idea as to what you are going to use it for. Bringing 220v under your seat sound a little dangerous to me. If you wish to use it for charging or any other use is there not a safer place to put the socket. I have a 4 gang socket in the garage and is fitted very safely and used for charging, cooking and keeping beer cool in the cool box.

 

Hi how are you? thank you for your input, yes it will be for charging my leisure battery which is also mounted under the dining area seating. But the battery is securely fastened down and adequately vented through the floor, so not a problem. The mains socket will be fed directly to the consumer unit via a 16A MCB, and the socket will be a 1 gang double pole socket which is in accordance with the current regulations on fitting any new mains sockets to a motorhome/caravan.

 

Can't see it been any more dangerous then where it was before when the motorhome was made 21 years ago, the consumer unit, 230v charger, 12v power distribution unit were all fitted next to my gas isolation valves to turn on the gas appliances. surely it would only take a small gas leak and a tiny spark and oh boy, fireworks comes to mind.

 

There is a gas Truma water heater also fitted under the seats, but I have fitted a piece of 12mm plywood right across separating the two areas, not sure if necessary. Also I have my split charge relay in this area now so works much better I think.

[Fiat Ducato]

aandy - 2018-02-06 12:31 PM

 

You don't say what sort of cable you plan to use, but I've been told by those who know (which I certainly don't when it comes to electrics) that vehicle applications should always use cable with a multi strand conductor, rather than the single core domestic stuff, as the latter is adversely affected by movement and vibration.

 

Hi thanks for your comments, I did mention, you must of missed it. I will be using 3 core 1.5mm 16A rated, heat and frost resistant flex cable which is multi strand cable.

 

I would never ever use standard domestic cable as it too rigid and can break with vibrations and pot holes, speed bumps etc.

 

When I first bought my motorhome the person before me and fitted a large length of 2.5mm twin and earth domestic cable to the 12v system and that was one of my very first jobs, removing it asap.

[StuartO]

Fiat Ducato - 2018-02-07 3:17 AM  .... Just unclear about having it running outside of van. Maybe the conduit as to be of a certain material and so as now mains flex is visable.

 

I doubt the Regs will mention MH installations specifically, so you may find there is no official guidance.  Running main flex (and it should be flex rather than cable of course) inside conduit should be perfectly safe as long as its adequately supported along its length.  In the extremely unlike event of the flex being damaged by road debris or vermin underneath the MH, your circuit safety devices will kick in if necessary.

 

[Fiat Ducato]

StuartO - 2018-02-06 12:38 PM

Fiat Ducato - 2018-02-07 3:17 AM  .... Just unclear about having it running outside of van. Maybe the conduit as to be of a certain material and so as now mains flex is visable.

 

I doubt the Regs will mention MH installations specifically, so you may find there is no official guidance.  Running main flex (and it should be flex rather than cable of course) inside conduit should be perfectly safe as long as its adequately supported along its length.  In the extremely unlike event of the flex being damaged by road debris or vermin underneath the MH, your circuit safety devices will kick in if necessary.

Thanks Stuart that's more or less what I was thinking. The vermin thing worried me but then I though there is all sorts of 12v exposed cable and cable within conduit in the engine bay of most vans and cars, and you never worry about vermin eating them lol,

[weldted]

Ionder if you consider using three core 1.5 mm artic cable, it remains flexible in cold weather I know you are going to mount in in conduit but there will still be some movement.

[Derek Uzzell]

Fiat Ducato - 2018-02-06 12:17 PM

 

...I understand that the Regs for mains in a motorhome state that a Double Pole socket must be used...

 

...the socket will be a 1 gang double pole socket which is in accordance with the current regulations on fitting any new mains sockets to a motorhome/caravan...

 

I’d be interested to know how you have come by that understanding, as the majority (all?) non-UK-built motorhomes marketed in right-hand-drive format in this country have unswitched UK-norm 3-pin 230V sockets (Example photo attached).

 

If you are going to use a UK ‘domestic’ socket, it makes good sense to fit a double-pole version, but even if there were some DP-socket-related regulations or recommendations that UK manufacturers (or UK ‘self builders’) follow when building new motorhomes, you’ll be DIYing a 1997 Italian-made vehicle.

 

It’s clearly preferable to avoid running mains electrical cabling, gas and water pipework or hot-air trunking below a motorhome’s floor, but I’ve seen blown-air trunking snaking beneath a motorhome and my 2005 Hobby had an unprotected underfloor gas-pipe crossing from one side of the vehicle to the other - and those instances were on brand-new Type-Approved motorhomes not DIY adaptations.

 

With DIY modifications there will often be a point where practicability overrides preferability. My Hobby was plentifully endowed with 230V sockets, but my 2015 Rapido 640F model has as standard a single 230V unswitched 3-pin socket positioned adjacent to the gas-hob. It would have been a simple matter when the Rapido was built to install additiional sockets in the living area and, for 2016, Rapido added a 2nd socket. (This, however, was in the rear garage presumably because it was easy to do!) I fitted a twin socket (similar to the attached photo) but it’s in the bedroom area rather than the lounge area where I’d like it to be. But the Rapido’s design makes it impracticable to run a cable from the under-bed mains ‘consumer unit’ to the lounge area and keep the cable inside the vehicle.

 

As you’ve said in your first paragraph, the first choice would be to run the mains cable through (or above) the floor. But if you can’t do that, I very much doubt (as Stuart has said) that there are any UK regulations forbidding you from taking the underfloor route.

[Fiat Ducato]

Derek Uzzell - 2018-02-07 8:28 AM

 

Fiat Ducato - 2018-02-06 12:17 PM

 

...I understand that the Regs for mains in a motorhome state that a Double Pole socket must be used...

 

...the socket will be a 1 gang double pole socket which is in accordance with the current regulations on fitting any new mains sockets to a motorhome/caravan...

 

I’d be interested to know how you have come by that understanding, as the majority (all?) non-UK-built motorhomes marketed in right-hand-drive format in this country have unswitched UK-norm 3-pin 230V sockets (Example photo attached).

 

 

Good morning Derek, little confused. do you mean how did I come to the conclusion that Double Pole sockets must be used in motorhome/caravan, which Regs etc?

 

I read it on an official website somewhere, if you would like I can try and find it again. It's for the extra protection. Regarding reverse polarity etc. The use of double pole switching guards against the dangers associated with a Live/Neutral reversal. In this circumstance a single pole would break the circuit on the neutral leg and the device would not operate HOWEVER lurking within would be the Live and the associated danger of electrocution. If both Live and Neutral are switched then this possibility is removed. In summary so long as everything is wired correctly single pole will suffice but to guard against a Live/Neutral reversal double pole switching will always ensure safe disconnection.

 

And the bit about using standard domestic sockets in motorhomes, well that is exactly what I have used a standard single double pole socket and pattress from MK range top quality, and with a switch. There is no specification with the regs on what type of socket to use, just that it should be DP.

 

Hope this clears things up. :-)

[Fiat Ducato]

weldted - 2018-02-06 10:30 PM

 

Ionder if you consider using three core 1.5 mm artic cable, it remains flexible in cold weather I know you are going to mount in in conduit but there will still be some movement.

 

Hi that is exactly what I am using ;-) Blue Artic flex much more expensive than regular flex but as I only needed 3m I thought what the hell. And I'm fairly sure it is higher rated as well up to 16A instead of 13A like standard flex.

[colin]

The only thing I would say, is there is a slightly raised risk of vermin damage causing a dangerous earth fault, whilst the supply earthing should take care of this it's not 100% guaranteed. I had a rubber gas pipe on a caravan chewed through on two consecutive days, and had to resort to flexible armoured conduit, I'm not sure vermin find the plastic on wires as 'tasty' as rubber.

[Derek Uzzell]

Fiat Ducato - 2018-02-07 10:50 AM

 

...Good morning Derek, little confused. do you mean how did I come to the conclusion that Double Pole sockets must be used in motorhome/caravan, which Regs etc?

 

I read it on an official website somewhere, if you would like I can try and find it again....

 

Yes please.

 

I’m well familiar with the rationale behind fitting double-pole socket outlets, and I’m also aware that Allan (of A and N Caravan Services) discusses the matter on his own website.

 

However - to the best of my knowledge - I am unaware that there are any UK regulations prohibiting you from a) running a mains cable under your motorhome’s floor or b) obliging you to fit a switched DP socket-outlet at the cable’s end rather than a single-pole switched socket or an unswitched socket.

 

There’s a basic difference between ‘legally unacceptable” (ie. there’s a regulation forbidding it) and “acceptable but not best practice”. It’s best practice that you fit a DP socket-outlet (but I don’t believe that’s mandatory), whereas it’s not best practice to run underfloor the cable leading to the socket-outlet, but I believe there’s no UK regulation forbidding you from doing this.

[flicka]

Am i missing something fundamental??

Why would you even want to run an external supply through the floor to under the seat ??

It's going to be awkward to detach when wanting to move the van especially in wet weather.

Is there ANY reason why your supply lead can't use the normal EHU socket ???

 

[Derek Uzzell]

As I understand it Paul (Fiat Ducato) is asking about the regulatory acceptability of running a supplementary 230V cable from his Auto-Roller’s ‘consumer-unit’ (example in attached photo) that’s somewhere inside the motorhome. The cable would go from the consumer-unit down through the motorhome’s floor, then forwards beneath the floor, then upwards back through the floor to emerge under the motorhome’s seating where a DP socket-outlet would be added to the cable.

 

(The principle is similar to that often used to run a cable connecting a rear-mounted reversing camera to a monitor in the cab, as it can be a lot simpler to route the camera-to-monitor cable under the floor than to try to lead it through the motorhome’s interior.)

 

Mains electricity entering Paul’s motorhome (from an external 230V power supply like a campsite hook-up pedestal) and arriving at the consumer-unit would be unaffected by the modification.

[fred22]

Mains electricity is covered in Chapter 8 of "The Caravan Manual".

 

I am sure it is covered in the Motorhome Manual but I cannot find mine.

 

Section 6 on page 103 explains the need for"Flexible Cable"

[Derek Uzzell]

I assume you are referring to the John Wickersham’s publications?

 

There’s a chapter on motorhome electrical systems in JW’s book “The Motorcaravan Manual”, and also in his book “Build your own Motorcaravan” (that should be worth obtaining for anyone planning to undertake a major revamp on an older motorhome).

 

Paul (Fiat Ducato) described the cable type he would be using in his posting of 6 February 2018 12:37 PM above.

 

It’s tempting to think that no person with a grain of sense would use ‘domestic’ single-strand cable (rather than multi-strand) when modifying a motorhome’s electrical system, but Paul mentions that a previous owner had done just that.

[Fiat Ducato]

Hi thanks Derek, yes and 2.5mm twin and earth as well, so some hefty domestic cable. One of the very first jobs I did was to to remove this dangerous wiring setup, they had it connected to an inline blade fuse then feeding the electric step all from the 12v unit.

 

I've completed the job I was doing, like everything on my motorhome, fix one thing and along the way something else breaks, I used blue artic 1.5mm flex, running directly from the consumer unit under the van in conduit and fastened to the underside of the van with plastic conduit fixings. Whist removing the short length of flex which was going to consumer board (for feeding my old 12v unit/230v charger) and replacing it with the new flex, a tiny piece of plastic broke off the area where the wire enters and is tightened up with screw. Spent ages trying to work out why when I tightened the screw the wires still kept coming out. After removing the entire RCD/MCB it was clear why. Took it to my local CEF store and showed them the RCD unit and they said they had never seen anything like this, it is a sort of RCD with a built in breaker. Weird as I thought that's what RCBO are??

 

Anyway ordered a new 16A RCBO from online and it arrived all fitted and test and all working perfectly.

[Fiat Ducato]

Fiat Ducato - 2018-02-18 8:57 AM

 

Hi thanks Derek, yes and 2.5mm twin and earth as well, so some hefty domestic cable. One of the very first jobs I did was to to remove this dangerous wiring setup, they had it connected to an inline blade fuse then feeding the electric step all from the 12v unit.

 

I've completed the job I was doing, like everything on my motorhome, fix one thing and along the way something else breaks, I used blue artic 1.5mm flex, running directly from the consumer unit under the van in conduit and fastened to the underside of the van with plastic conduit fixings. Whist removing the short length of flex which was going to consumer board (for feeding my old 12v unit/230v charger) and replacing it with the new flex, a tiny piece of plastic broke off the area where the wire enters and is tightened up with screw. Spent ages trying to work out why when I tightened the screw the wires still kept coming out. After removing the entire RCD/MCB it was clear why. Took it to my local CEF store and showed them the RCD unit and they said they had never seen anything like this, it is a sort of RCD with a built in breaker. Weird as I thought that's what RCBO are??

 

Anyway ordered a new 16A RCBO from online and it arrived all fitted and test and all working perfectly.

 

And I just want to point out for those who don't read the whole thread before commenting that the first photo is what the wiring looked like when I first bought my motorhome, and it does not look like that now, between a faulty 12v Nordelettronica unit, with built in 230v charger that just stopped working I have had to completely change everything, can say now that my complete camper as had all new wiring throughout. When I renovated/repaired the water ingress damage to the ceiling I run all new cables through with LED lighting, new LED spotlights.

 

But finally it works how I want it to work, fridge relay works all the time and doesn't keep switching on and off like before due to a faulty connector on the unit, same with the split charging works as it should now and not intermittently like it used to again due to faulty connector on unit.

 

The 20A mains charger I have fitted now, charges both my leisure battery and vehicle battery when switched on EHU. Via the VSR, so after only 4 hours I have both batteries completely charged.

 

All I want to do now is fir a solar panel to the roof with a MPPT controller, maybe add another 90Ah battery.