Caravan site wiring

[nickjohn]

Sorry about asking this question as I think similar posts have been made before but I could not find one along the same lines as this.

A friend of mine has a residential static caravan site (as in the caravans on the site are lived in 24/7 52 weeks a year by the same people).
The configuration of the site wiring is there is a central building incorporating the incoming mains which splits into individual meters for each van, this goes to a 60a sw fuse then into a 60A 30ma RCD then a swa sub main (with the old vans the swa went into the van and connected into a CU incorporating another 60A 30ma rcd and breakers) with the new vans the sparks has installed an external housing adjacent to the van which has a cu with a 60A 30ma rcd and 16A breaker, this then connects to an external 16A socket with a flex into the vans CU - the new vans cu has a 30ma RCD.

He says the vans must have a means of disconnection of the supply adjacent to them as they are mobile homes... some have to be lifted in with a crane so they are not mobile in the true sense of the word.. he also says the vans are limited to what they can use electrically wise as they are mobile homes hence the 16A breaker.

Now the problem is that as the vans are permanent residences they have washers / dryers / toaster / TV's / kettles etc etc which puts more load on them than say a holiday home.

My friend does not understand why we cannot just connect the swa direct into the van as they were before as the swa has an rcd at source which should give the protection necessary, also the small 16A breaker is already causing problems with the resident as it overloads all the time.

Can anyone shed any light on what is the correct connection configuration.

 

[nickjohn]

Well, what do the Regs say...

Well Richy3333, not sure as I do not have a copy hence asking the question in the first place....I assumed the forum would be a place whereby people with suitable knowledge would be able to offer assistance and advice based on experience, guess I will just have to get the latest copy of the regs and take it from there...

 

[spark 68]

Sorry to bring this up again but if you have the 30ma protection at source of the swa could you get away with fitting a commander socket onto the swa then a plug / lead arrangement into the van (having a cu in the van with an rcd / breakers etc)???

The short answer is No.

The Pitch socket needs to comply with BS EN 6039-2, have an IP rating of at least IP44, each S/O needs it's own individual OCPD and RCD.

If you are planning on getting involved with this type of install then I would seriously suggest you also get a copy of GN7 as well as the BGB.

 

[itselectric]

So you have a garden shed which is not a permanent structure, yet you wire direct to internal fuseboard. What's the difference to a static caravan which will only be removed to be replaced with another. these are no different to a bungalow.

 

[spark 68]

A caravan has a (earthed and Bonded) metal chassis for a start, hence why PME is not allowed.

They both (van and pitch) are covered by different sections of the regs, the pitch being a commercial venture/open to the public will also be covered by EAWR amongst other things which is statutory, this is not just a shed in your back garden.

 

[happysteve]

the fact is:

just because it is considered a `static`...this does not mean that it cant be moved...at any time...

its just a case of getting a flatbed...and a winch to drag it on with...

so consequently the DNO are justified in considering them moveable/portable/not perminant structures....

I'm trying to understand these comments (which make sense) with respect to the regs.

Bear in mind my status (see sig) I am only trying to increase my knowledge, so please tell me where my reasoning is out.

721 "Electrical Installations in caravans and motor caravans"

721.1 Scope

Blah blah

"They do not apply to the electrical installations of mobile homes, residential park homes and tranportable units.

NOTE 1: For mobile homes and residential park homes the general requirements apply"

"Mobile homes" are defined in Part 2: "A transortable leisure accomodation vehicle which includes means for mobility but does not meet the requirements for construction and use of road vehicles."

So this is your "static caravan" and, whether lived in all year round or not, makes no difference to the regs, and isn't covered by 721.

Given the OP's description of the caravan site, I'd say 721 isn't relevant. Anyone beg to differ?

Then I looked at 708 "Electrical Installations in Caravan / Camping Parks and Similar Locations"

708.1 Scope

"The particular requirements of this section apply to that portion of the electrical installation in caravan / camping parks and similar locations providing facilities for supplying leisure accommodation vehicles (including caravans) or tents."

Part 2 defines leisure accommodation vehicle: "Unit of living accommodation for temporary or seasonal occupation which may meet requirements for construction and use of road vehicles."

The important word there is "may" - so if it doesn't, but is nevertheless a unit of living accommodation for temporary or seasonal occupation, it's within the remit of 708. To me, this says, "static holiday homes are covered, residential homes are not." Anyone beg to differ?

708.411.4 states that ESQCR prohibits connection of PME earthing facility to any metalwork of your... let's just call it a van... your van.

708.530.3 Caravan pitch supply equipment "... shall be located adjacent to the pitch and not more than 20m from the connection facility on the [van] when on its pitch."

BGB does not define "supply equipment" but I read this as "switchgear and control gear". So, RCDs, overcurrent protective devices etc. So this says to me, "if you're going to have an RCD/MCB, it has to be near the van." Anyone beg to differ?

Now, it's been 20 years since I lived on a caravan park (which my folks owned, up near Bradford), but in them days, statics didn't come with nice shiny ceeforms. They were wired in by a [qualified] electrician (a bloke called Ian, in our case), like a permanent installation.

708.553.1 talks about "plugs and socket-outlets" but there are some paragraphs relating to fixed connections:

708.553.1.12: "Blah... A fixed connection for supply to each [van] shall be protected individually by an overcurrent protective device, in accordance with the requirements of Chapter 43."

I take this to mean, "You need an MCB or similar, but it doesn't proscribe what value, for a fixed installation." Anyone beg to differ?

708.553.1.13: "Blah... Final circuits intended for fixed connection connection of the supply to [vans] shall be protected individually by an RCD having the characteristics specified in Regulation 415.1.1."

(415.1.1 is under additional protection, states "30mA RCD").

So taking all that into account, I read the requirements for static caravans, with a fixed supply (ie not connected by ceeform), there should be a 30mA RCD and an overcurrent protective device within 20m of the van.

Now, where the "two 30mA RCDs in series" bit comes in I don't know, as I haven't read the whole of the BGB yet (I'm working on it!). From a pragmatic point of view, if your van's CU also had a 30mA RCD fitted then yeah, there'd be no discrimination, so you wouldn't know which one would go... but if it happened to be the one in the van, you might save yourself having to go out in your dressing gown and slippers. 531.2.9 talks about discrimination and RCDs in series, "the characteristics of the devices shall be such that the intended discrimination is achieved." HOWEVER, this is only required "where discrimination in their operation is necessary to prevent danger," and I don't perceive this to be the case, here. Anyone beg to differ?

Like I say, just trying to learn. Still confused by "the DNO are justified in considering them moveable/portable/not perminant structures" which as I say does make sense, but through lack of experience an knowledge I don't know what the relevance of this is.

Owt wrong with any of my reasoning with respect to scope and relevant bits of the BGB?

 

[nickjohn]

Just got a copy of "guide to the wiring regs" from the ECA.
Section G5.

"Caravan: A trailer leisure accommodation vehicle, used for touring, designed
to meet the requirements for the construction and use of road vehicles."

The large static "caravans" are not constructed for road use as they have no brakes for a start..



708.530.3 Caravan pitch supply equipment "... shall be located adjacent to the pitch and not more than 20m from the connection facility on the [van] when on its pitch."

As these are permanent statics could you put the connection point within the van?? make things easier if the trip went at 2 in the morning on a wet night..

 

[spark 68]

Mobile or transportable units are covered by section 717

The scope for this section specifically excludes caravans.

717 refers to either:
i) self propelled vehicles or towed
ii) containers or cabins

In general the requirements in 717 are very similar to 721, except where they are even more onerous and complicated in cases of an onboard generators and the like.

It also differs in that section 721 mentions in Scope that this applies to "habitation purposes" where as section 717 does not, section 717 refers to examples of "technical facillities, fire fighting units, medical units, workshops offices etc....etc., in other words everything else apart from habitation purposes

re: 721 note 1, where it says "for mobile and residential park homes the general requirements apply"
it is referring to the general requirements for that section ie. 721

GN7 helps a lot in explaining the convoluted way the regs are written.

 

[happysteve]

Just got a copy of "guide to the wiring regs" from the ECA.
Section G5.

"Caravan: A trailer leisure accommodation vehicle, used for touring, designed
to meet the requirements for the construction and use of road vehicles."

The large static "caravans" are not constructed for road use as they have no brakes for a start..

Yes, hence all the stuff in 721 not relevant.

708.530.3 Caravan pitch supply equipment "... shall be located adjacent to the pitch and not more than 20m from the connection facility on the [van] when on its pitch."

As these are permanent statics could you put the connection point within the van?? make things easier if the trip went at 2 in the morning on a wet night..

Stuff in bold: this is pretty clear. Adjacent to the pitch does not equal in the van.

Stuff in red: makes no difference. 708 already makes allowances for the fact that these are for "leisure accommodation vehicles." (see definition in previous post, or Part 2 of the BGB),meaning static caravans. This definition states "temporary or seasonal occupation." So residential homes are not covered by 708 so the extra stipulations (above and beyond BGB regular stuff) don't apply. For residential homes you might well be able to tail straight in without "caravan pitch electrical supply equipment" - I don't know on this one. Seek advice from those experienced.

As I understand it, there are several ways in deciding whether it's a holiday static or a residential home. Council tax is the easiest, and the site owner will definitely know.

Sounds like you need a copy of the BGB.

vvv take note. vvv

 

[happysteve]

re: 721 note 1, where it says "for mobile and residential park homes the general requirements apply"
it is referring to the general requirements for that section ie. 721

GN7 helps a lot in explaining the convoluted way the regs are written.

Umm... forgive me, my take on that is different. Where in the note it says "the general requirements apply" I take this to mean the rest of the BGB.

As evidence, since you refer to GN7, page 11: "The particular requirements of Part 7 of BS 7671 supplement or modify the general requirements contained in the remainder of the standard." (my emphasis)

(this is basically repeating 700 of the BGB).

A static caravan is a mobile home (as defined in Part 2).

"The requirements [of section 721] do not apply to the following: electrical installations of mobile homes or residential park homes, to which the general requirements apply." (GN7, page 52).

I take all that to read, "721 does not apply to static caravans (or residential park homes)".

Anyone?

 

[spark 68]

section 7XX modifies and also supplements the other regs in the book in both BS7671 and GN7 (which of course is referenced to the regs), so you have to back track to the original reg and then intereprate what the modification/supplementary information is.

In section 721 note one, it states "the general requirements apply" (my emphasis), if it did not refer to this section it would have said general requirements apply, or given the basic reg numbers.
As you have pointed out further in your post, where it says "the requirements (meaning this section,721) do not apply to the internal electrical installation of leisure vehicles"

"The requirements [of section 721] do not apply to the following: electrical installations of mobile homes or residential park homes, to which the general requirements apply." (GN7, page 52).

Of course it doesn't, the CU and wiring inside of the caravan is just covered by the standard regs as any other installation would be, why would it be any different ?
Section 721 only refers to the additional and supplementary regs over and above the normal that is associated with the peculiarity of that type of install, it tells you this at the very top of page 52 of GN7.

 

[nickjohn]

Ordered a copy of the BGB something to read on those lonely winter nights...

 

[happysteve]

section 7XX modifies and also supplements the other regs in the book in both BS7671 and GN7 (which of course is referenced to the regs), so you have to back track to the original reg and then intereprate what the modification/supplementary information is.

Agreed. Sort of. I don't think there necessarily needs to be an original reg. "The particular requirements for each section (special installation or location) in Part 7 supplement or modify the general requirements contained in other parts of the Regulations." (700, BGB). So you can supplement or modify "the general requirements."

In section 721 note one, it states "the general requirements apply" (my emphasis), if it did not refer to this section it would have said general requirements apply, or given the basic reg numbers.

I disagree. I don't believe the distinction between "the rest of the BGB" (which is what I take to be meant by "the general requirements" and "this section specifically" (which seems to be what you're implying) rests on the presence or absence of the word "the". If it does, then surely 700 from the BGB (quoted above) would instead state: "The particular requirements for each section (special installation or location) in Part 7 supplement or modify general requirements contained in other parts of the Regulations."

As you have pointed out further in your post, where it says "the requirements (meaning this section,721) do not apply to the internal electrical installation of leisure vehicles"

Of course it doesn't, the CU and wiring inside of the caravan is just covered by the standard regs as any other installation would be, why would it be any different ?

The whole point of these "special installations or locations" is to "supplement or modify" "the general regulations". So yes, the vast majority of the CU and wiring inside the caravan is covered by the standard regs. Then the relevant sections of 721 supplement and modify these.

721 refers to "Electrical installations in caravans and motor caravans." So, the stuff inside the vans, not on the site (which is covered in 708).

Does 721 cover trains? No. It's pretty obvious it doesn't cover trains, so it doesn't mention trains. The BGB is pretty dull as it is, imagine if every time it mentioned something new, it said, "Oh, by the way, we're not talking about trains."

How about moon buggies? Again, no.

How about static caravans? They're caravans, right? Surely they must be covered under 721? And residential park homes? After all, they're rolled off the low loader on wheels, they even come with a tow bar (removable), so that makes them a caravan, in terms of the scope of 721 (which is "special installations or locations" to "supplement or modify the general regulations".)? Well, no:

"721.1 Scope: The particular requirements of this section apply to the electrical installations of caravans and motor caravans at nominal voltages [blah blah]. They do not apply to the electrical installations of mobile homes, residential park homes and transportable units."

So section 721 does not apply to mobile homes or residential park homes or transportable units.

I wonder if there are any special requirements for these sorts of things (since it mentions them)? "Note 2: For transportable unit, see 717" Ah, so transportable units has a special section. What about mobile homes and residential park homes? "Note 1: for mobile homes and residential park homes the general requirements apply."

So for mobile homes, the general regulations apply. Nothing mentioned in 721 applies, in the same way that nothing in 721 applies to a house.

Section 721 only refers to the additional and supplementary regs over and above the normal that is associated with the the peculiarity of that type of install, it tells you this at the very top of page 52 of GN7.

I agree entirely. I think where we differ is whether 721 the "particular type of install" covers static caravans or not. I say not.

 

[D Skelton]

I wonder if there are any special requirements for these sorts of things (since it mentions them)? "Note 2: For transportable unit, see 717" Ah, so transportable units has a special section. What about mobile homes and residential park homes? "Note 1: for mobile homes and residential park homes the general requirements apply."

So for mobile homes, the general regulations apply. Nothing mentioned in 721 applies, in the same way that nothing in 721 applies to a house.

I agree entirely. I think where we differ is whether 721 the "particular type of install" covers static caravans or not. I say not.

Section 717 deals with mobile or transportable units, exaples of such units include technical and facilities vehicles for the entertainment industry, medical or health screening services, welfare units, promotion and demonstration, firefighting, workshops, offices, transportable catering units etc.

Nowhere does it mention here mobile or transportable units suitable for habitation, thus we end up back at section 721. If this isn't enough to sway your opinion maybe this is; Section 29 (1) of the Caravan Sites and Control of Development Act 1960 ("The 1960 Act") a caravan is defined as any structure designed or adapted for human habitation which is capable of being moved from one place to another (whether by being towed, or by being transported on a motor vehicle or trailer) and any motor vehicle so designed or adapted.

A static caravan falls quite clearly into this description, therefore the only conclusion that can be drawn from this is that static caravans are caravans, therefore they are covered by section 721.

 

[spark 68]

It is the wording of the regs that is the problem, there is a lot of grey areas and overlap, and some incompatibities, also a few downright mistakes, they have to produce a series of guides for a guide for christ sake.

I still maintain you are incorrect about the wording in section 721, (I do have some training on this aspect :wink_smile, and it does refer to that section.

If I can find some other material that helps I will post it up, I may still have some course notes.

Caravans are mostly off the beaten track where the subject is just skimmed past on most courses, it is mostly common sense when you actually get into the nuts and bolts of it.

the parts of the wiring of the caravan itself in that section refer to permitted wiring types, ELV, DC supplies and other things which you would only really be bothered about if you were actually designing, building or repairing the things, and are not really relevent to this thread, the parts we are discussing here are covered on pages 57 and 58 of GN7, 7.6.1, 7.6.2 and 7.6.5 and 7.6.6, and mainly concern the supply to the caravan in conjunction with section 708

Part of section 721 see above paragraph (GN7 pg 57 and 58, 7.6.1, 7.6.2, 7.6.5 and 7.6.6) is also dependent to a large extent on the site/pitch at which it is based, which may (probably will be) be bound by it's own regs (section 708), the regs should not be taken in isolation they depend on other factors and sections in the BGB, sometimes you have to satisfy two very different seemingly contradictory criteria.

 

[happysteve]

Section 717 deals with mobile or transportable units, exaples of such units include technical and facilities vehicles for the entertainment industry, medical or health screening services, welfare units, promotion and demonstration, firefighting, workshops, offices, transportable catering units etc.

Nowhere does it mention here mobile or transportable units suitable for habitation, thus we end up back at section 721.

Agreed.

If this isn't enough to sway your opinion maybe this is; Section 29 (1) of the Caravan Sites and Control of Development Act 1960 ("The 1960 Act") a caravan is defined as any structure designed or adapted for human habitation which is capable of being moved from one place to another (whether by being towed, or by being transported on a motor vehicle or trailer) and any motor vehicle so designed or adapted.

A static caravan falls quite clearly into this description,

Interesting reference. I agree with you, according to this reference, (and generally) I would also call a static caravan a caravan too.

The BGB makes distinctions, though, that the 1960 Act does not. Why would this be the case? Well, tourers, camper vans suffer lots of vibrations as they get moved around for one thing... hence the supplementary requirements of (eg) 721.521.2 (flexible class 5 conductor or stranded cables) and 721.522.7 (vibration). Statics don't get moved around as much. Are statics wired in T&E? (Open question, I don't know the answer... they were 20 years ago, no idea about now!)

... therefore the only conclusion that can be drawn from this is that static caravans are caravans, therefore they are covered by section 721.

Against someone as respected and experienced as yourself, and others who disagree with my perspective on this, I know my words pretty much count for nothing.

So please help me understand how, within the scope of the BGB, "caravan" is clearly defined in part 2, as is "motor caravan"; both definitions exclude mobile homes and residential park homes ("statics"), as they are not "designed to meet the requirements for the construction and use of road vehicles." 721.1 explicitly states, "The particular requirements of this section... do not apply to the electrical installations of mobile homes, residential park homes."

Is there genuine ambiguity here?