Static Caravan Park Thought?

[craig1000]

Hi

We have been asked to look at continuing some mains distribution upgrade / improvements works at a permanent static caravan park.

Trouble is the works that have been started I don't think in many ways comply to regs - first time doing caravan park works though so my understanding on the regs for this is limited thus far as not having gone though it before.

Can you confirm my thoughts that all the 'caravans' themselves need to be earthed via a TT system?

The main incomer to the site has been made PME not too long back and the person who started the work for the caravan park ( a family friend who worked for a firm as a sparks mate/improver and has sadly passed away ) has taken a 3 phase PME supply to 3 external positions via 5c 25mm SY cable and then taken 6mm SWA via a RCD into the 'caravans'.

He has continued though the PME earth through - my thoughts and understanding is this should stop at the external positions (external meter box with henlys blocks in and then picking up a phase to a RCD unit) and the 6mm supply to the 'caravans' should be picked up via a local earth rod TT system?

He has also left this 3 phase supply yo be installed on 3 separate single phase MCB's as opposed to a 3 phase breaker? ;-/

There has been no paperwork thus far issued or design paperwork from whet was originally started and I now need to try to finish it - whilst explain that I think some parts of what he has already paid for need changing further - just wanted to check my views and gain others thoughts before I speak to the client?

Ask for further info and I shall provide if possible.

Cheers in advance for any replies and thoughts given on this.

Craig

 

[telectrix]

why has he used SY and not SWA? you're right in thinking that the PME should not be used and each point of use should be TT'd.

 

[craig1000]

No idea why he has gone with SY - as I say it has been done / was started by a friend/family member of the proprietors who worked in the electrical industry as a mate but was not electrically trained :-(

He has just done what he thinks and what is easiest I guess and probably taken a few pointers from lads he worked with.

I now need to assess it fully and design it correct - all whilst trying to explain to the proprietors they in some instances will need what he has done changed - pain in the --- as they just look saying well it's working OK lol

 

[Engineer54]

Unfortunately there is no need to go any further than the use of SY cable in this installation!! It does not comply in any way shape or form for a direct buried or even buried ducted system. So i'm afraid all the cable so far installed needs to come out, before you start looking into any other aspects of the job!! What's the betting he's used the braiding as the CPC too?? ...lol!!

 

[craig1000]

The fact that it is a 3 phase and neautral supply going out through the external positions into henlys blocks BUT using 3 single phase MCB's so they can isolate 'sections' of the park too makes me worry as to what else we will find as we assess it further ;-/

 

[craig1000]

Unfortunately there is no need to go any further than the use of SY cable in this installation!! It does not comply in any way shape or form for a direct buried or even buried ducted system. So i'm afraid all the cable so far installed needs to come out, before you start looking into any other aspects of the job!!

Cheers for that - back in the office today to start disecting what I have found installed and do a design for it.

It also has a temp section of the 'old' existing part of this circuit that is fed in 6mm cable asa "temp" measure due to the old cable going down - so back up by a 63amp supply feeding 5 units.

The place is a mess.

 

[Engineer54]

The fact that it is a 3 phase and neautral supply going out through the external positions into henlys blocks BUT using 3 single phase MCB's so they can isolate 'sections' of the park too makes me worry as to what else we will find as we assess it further ;-/

Forget all that crap, that can be sorted out as you go along, your main concern right now, is that the cable installed is not suitable for burial, and maybe a few other things as well. If the park owners are not prepared to undertake this installation correctly, then my advice is to run away as fast as your legs can carry you, you will exposing yourself wide open, if anyone on this park is ever injured/maimed or even killed due to the parks electrical installation....

 

[amckay]

The fact that it is a 3 phase and neautral supply going out through the external positions into henlys blocks BUT using 3 single phase MCB's so they can isolate 'sections' of the park too makes me worry as to what else we will find as we assess it further ;-/

Forget all that crap, that can be sorted out as you go along, your main concern right now, is that the cable installed is not suitable for burial, and maybe a few other things as well. If the park owners are not prepared to undertake this installation correctly, then my advice is to run away as fast as your legs can carry you, you will exposing yourself wide open, if anyone on this park is ever injured/maimed or even killed due to the parks electrical installation....

I couldn't agree more.
However you communicate with the client do so in writing and only accept written responses from them. It might sound like a ball ache but if you do go ahead with the job at least your are is (semi) covered should anything happen.

 

[craig1000]

Don't worry I haven't touched anything as yet - just had a good look at what is there, whats been started and discussions of what they are trying to achieve.

I'm going to point out the obvious flaws and depending what the response is I'll then spend some time to put a design to it and quote based on said design.

We won't be going anywhere near it unless we are putting it right.

Just this circuit alone that has been started is a complete mess -

Paper lead from intake position 3 phase DB goes to underneath a caravan where it made off into what appears to be a large AD box with no lid wrapped in plastic - I dared not touch it to get a proper look.

Out of this comes a 'temp' length of SY 5c 25mm into an external meter box and then a further length of this SY feeds up to another external meter box.

At the first meter box 1 caravan is fed via a 6mm.

At the 2nd position 2 separate 6mm swa's feed 2 other caravans.

All the 6mm's above mentioned are protected by RCD's in the external meter boxes.

THEN though there is a 6mm 3 core single phase swa not RCD protected running to further enclosures feeding 5!!!!! more caravans but changing back to the old paper lead at the next enclosure.

All this is currently connected to the PME earth system and the '3 phase circuit' is operated via 3 single phase MCB's.

Time to run as fast as I can.

 

[topquark]

Was this maybe started when the supply was TNS, that may excuse the earthing, as TNS would have been OK.

Technically they are static park homes not caravans for regs purposes ie no min 1.5mm cable. Bigger parks I've seen use busbar chambers for distro and feed a number of homes from each chamber.

Each van should have a switch fuse location (shed or purpose built containment) SWA supply and feed on into home. Either TT'd at switch fuse outbound side or consumer unit, the latter being much more preferable. Worth checking the utilities as they are sometimes not extraneous.

Most static parks will also need facilities for mobile van hook up, laundry rooms and shower blocks (often boiler supplied, but not always), so make sure they get taken into account for load design purposes.

 

[craig1000]

Was this maybe started when the supply was TNS, that may excuse the earthing, as TNS would have been OK.

Technically they are static park homes not caravans for regs purposes ie no min 1.5mm cable. Bigger parks I've seen use busbar chambers for distro and feed a number of homes from each chamber.

Each van should have a switch fuse location (shed or purpose built containment) SWA supply and feed on into home. Either TT'd at switch fuse outbound side or consumer unit, the latter being much more preferable. Worth checking the utilities as they are sometimes not extraneous.

Most static parks will also need facilities for mobile van hook up, laundry rooms and shower blocks (often boiler supplied, but not always), so make sure they get taken into account for load design purposes.

The DNO has upgraded to PME from a previous TNS system BUT the alterations began after this so it should have been taken into account. Even had it been altered after it would still now need taking into account.

 

[driverman]

If the homes are static homes (residential) they can be tn-s unless they are a caravan (mass of metal skin) I'm not too sure however if PME is allowed for a static home

 

[telectrix]

statics are still metal skinned. park homes are not, so PME is allowed for the latter.

 

[Guest77]

Tns- no problem, tncs- problem

 

[craig1000]

Tns- no problem, tncs- problem

To confirm then residential park homes on TN C S is a problem lol?

I am struggling to find anything to differentiate between residential parks homes and caravans/statics.

 

[topquark]

To confirm then residential park homes on TN C S is a problem lol?

I am struggling to find anything to differentiate between residential parks homes and caravans/statics.

Residential Park homes (statics) cannot be put on a car towbar and moved, (and generally have a brick skirt around them), caravans can and are mobile. See BGB definitions pg 24 and 33 respectively. Section 708 for parks and 721 for in the vans. 721.524.1 is the main 1.5mm conductor I referred to earlier. HTH.

 

[Guest77]

Residential Park homes (statics) cannot be put on a car towbar and moved, (and generally have a brick skirt around them), caravans can and are mobile. See BGB definitions pg 24 and 33 respectively. Section 708 for parks and 721 for in the vans. 721.524.1 is the main 1.5mm conductor I referred to earlier. HTH.

How much do you want to bet, they have A frames and although usually sit on breeze blocks and have wooden skirts around them so they look a permanent feature they can be moved in a matter of minutes lol

 

[topquark]

OK, perhaps I should have said "are not intended to" instead of cannot . Even on Singles the A frame is usually removed and stored underneath and with Doubles not a chance