BS7671:2018 SECTION 708

Phil Kinnaird said:

Section 708 clearly states that a Residential Park Lodge under ESQCR Regulations states that a PME earthing facility shall not be used for the means of earthing for this type of installation.

Are we talking about a residential park home or a static caravan?

Please could I ask how you came to the conclusion that BS 7671:2018 prohibits the connection of PME earthing to a residential park home?

Section 708 of BS 7671:2018 (and of BS 7671:2018+A2:2022) only prohibits connection of PME to leisure accommodation vehicles (regulation 708.411.4). A residential park home is not, in general, likely to come under the definition of 'leisure accommodation vehicle', which is stated in Part 2 of BS 7671:2018 (and BS 7671:2018+A2:2022). The term residential park home is separately defined. PME may be used on caravan sites for purposes other than supplying leisure accommodation vehicles.

Section 721 applies only to the installation within a caravan or motor caravan itself, and residential park homes are excluded from the scope of Section 721 (see Regulation 721.1).

Other than that, it is really not possible to comment on the suitability of a particular installation without seeing it.

Thank you for your comments which are very helpful. i am in fact  talking about a Residential Park Home.

I was taking the overall view indicated in 708.1 and being over cautious, as technically Residential Park Homes are still defined as Caravans.

Phil Kinnaird said:

as technically Residential Park Homes are still defined as Caravans

To be clear, there are definitely Residential Park Homes which are not classed as caravans (or even "static caravans"), and BS 7671 has, for some time, recognised that - and so has DNO guidance.

Have you tried getting in touch with a trade association to verify whether your particular home is classed as a caravan? The NCC might have some further advice: www.thencc.org.uk/.../aboutNCC.aspx

Phil Kinnaird said:

I was taking the overall view indicated in 708.1 and being over cautious, as technically Residential Park Homes are still defined as Caravans.

Technically not, at least as defined by BS 7671, where a caravan is something which is towed on the public roads.

Legally yes, under S.29 of the Caravan Sites and Control of Development Act 1960:

29 Interpretation of Part I.

(1) In this Part of this Act, unless the context otherwise requires—

• “caravan” means 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 ...

Do you have any information on where Residential Park Homes are not classed as Caravans (or Statics).Our Residents Association is registered with SCOPHRA who have published the information below.

My initial Question did give reference from Certsure to : UK Power Networks Engineering Design Standard  EDS 06-0017 CUSTOMER LV INSTALLATION EARTHING DESIGN Section 6.9 Mobile Homes, which is in line with your view.

EXTRACT on Legal Stuff FROM SCOPHRA SITE (www.scophra.scot)

Latest Legal Stuff 

Q. What makes a home mobile?

A. In legislation 'mobile home' and 'caravan' are synonymous and 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'.

The definition includes:

·         conventional caravans and mobile homes

·         dormobiles

·         touring caravanettes, and

·         adapted railway carriages.

A large, twin-unit caravan may come within the definition if it is:

1. designed for human habitation

2. capable of being moved from one place to another by being towed, or by being   

    transported on a motor vehicle or trailer in one, or two sections

3. shown to be capable of being disassembled into no more than two sections

4. length (exclusive of drawbar): 65.616 feet (20.00 metres) 

5. width : 22.309 feet (6.80 metres)

6. height: 10.006 feet (3.05 metres). 

The connection of mains water/electricity/sewerage or addition of cosmetic skirts that do not fix the structure to the ground do not prevent it from coming within the definition.

People sometimes ask if the addition of a porch or decking negates the position.

In the case of decking or a porch, provided it can be shown to be capable of being removed then the structure remains mobile.  The decking should not intrude unreasonably into the spacing between homes, for privacy purposes.

Where a conservatory is involved, this is a grey area yet lots of companies advertise conservatories for park homes so many local authorities must allow it. (Planning permission is required for any extension although some Councils do not seem to expect applications in this regard.)

There has been, to our knowledge, no test of the position in the Scottish Courts but since the Caravans and Control of Development Acts apply throughout the UK case law in England would likely be considered by a Sheriff.  See below:

Case law

A mobile home with an extension which was too wide to be moved lawfully on the public highway but could lawfully be moved if disassembled into two components each was held to be within the statutory definition of caravan.  Also within the statutory definition of a caravan was a mobile home attached by large bolts to a concrete wall and foundations, as it was possible to remove the bolts, and the wall and foundations were only under a small part of the mobile home.

The removal of the towing bar was no obstacle to transporting the home, as it could go on the back of a lorry.

I'll stir it a bit. Ignore the letter of the law for a moment, and look at the reasoning.. The question should be is 'is it dangerous' The problem with a caravan is same as a car on charge, the large area of external metal at suppliers earth potential that may be quite some way from the voltage of the terra-firma ground beneath your feet.

Is your park home a metal box connected to mains earth, or an electrically insulating one ?
Mike.

I think I would rather go with the letter of theLaw just in case something went wrong.

Most of the Residential Park Homes are supplies Via 3c SWA. Sometimes the SWA is utilised at the Lodge end and sometimes not, relying on an internal core for the Earth. They don't really bother about compliance with BS7671 in the main as the Site Managers answer is "that it is a caravan park".

Phil Kinnaird said:

I think I would rather go with the letter of theLaw just in case something went wrong.

To do that, you would need to be able to interpret the word "caravan" in the legislation and apply it to the circumstances of the particular installation ...  the legislation being the Electricity Safety, Quality and Continuity Regulations, 2002.

A court would usually use the legislation, and the relevant Standards (BS 7671 plus standards for the particular caravan or residential park home) ... although the duty is on the distributor in respect of the particular Regulation in question I believe.

The differentiation in BS 7671 is based on defining not a caravan, but specifically a leisure accommodation vehicle and the differentiator not whether it's transportable from one place to another, but whether it's fully towable on its own per the construction & use regulations.

As I pointed out earlier, the NCC will be able to help with a query on a particular park home, whether it ought to be classed as a residential park home or a leisure accommodation vehicle from the perspective of BS 7671.

Such interpretations I don't think (although I may be wrong) the contributors of this Forum could help you with further 'in the general case'.

Phil Kinnaird said:

Most of the Residential Park Homes are supplies Via 3c SWA. Sometimes the SWA is utilised at the Lodge end and sometimes not, relying on an internal core for the Earth.

BS 7671 permits, equally, TT, TN-S or TN-C-S (PME) earthing arrangements for residential park homes that are not classed as leisure accommodation vehicles. BS 7671 also permits, if it suitably sized for the installation, the steel wire armour alone, or a copper conductor in the cable on its own, or both together in parallel, to be a circuit protective conductor, if the earthing arrangement (whether TT, TN-S or TN-C-S) is supplied from the source end of the cable.

BS 7671 also permits the TT earth electrode to be connected only at the park home end of the SWA cable ... and further permits additional earthing of the circuit protective conductor (supplementary earth electrodes) for TN-S, TN-C-S and TT systems.

The Park is fully Licensed as a Residential Park Home Site by the Council.

From the comments received to date it would appear that the general consensus is that it is acceptable to connect to the DNO's PME system.

Now that we have had a bit of a debate, I have to support the Site Manager.