TNCS PME on caravan site with static caravan EICR

[fatgreeny09]

hi all i was just in the middle of doing an eicr on a caravan park and wanted some opinions on what codes are relevant to the site.

ive got tncs pme 100a 3 phase. each phase feeds a db like in the picture by a 100a main switch and 63 amp mcb and 10mm pyro (earthed with bonding clamp) which in turn feeds a static caravan by i think is 60898? 20a mcb (but could do with second opinion as im not as old as the mcbs) and 2.5 2 core swa connected directly to static home consumer unit again some earthed by bonding clamp at distribution board. no bonding at all to the chassis and no rcd except inside each static home

20180119_132736.jpg - https://drive.google.com/open?id=0BywXO5AAQnhsQkhwT002Q0NmdEpDUktXR01RVzhzZGxSVnZJ


all earth at the moment is exported from met tncs im thinking....


exported earth - c2
no rcd to each static home - c2
earth clamps on the swa c2 ( some are failing due to corrosion )
earth clamps on the pyro - c3
no extraneous bonding - c2
no earth at metal meters - c2

also these are not all defects just ones i was hoping for opinions on



ANNNDD... OPINIONS.... (plus abuse mildly welcomed !)

 

[fatgreeny09]

they are not a house ,but a static caravan and can be up lifted not like house permeant.

So 717 mobile or transportable unit..... no ?

 

[KEV 1 N]

They are type 4 Federal Electric devices and you need manufacturers data to compare Zs values. Sounds like you are out of your depth on this.

I’ve came across this type of DB before, and it had some newer mcbs fitted along the old ones, but they had to cut the lid of the DB to make them fit, unless they’ve put the wrong ones in and bodged it...

 

[westward10]

So 717 mobile or transportable unit..... no ?

What do you think.

 

[fatgreeny09]

What do you think.

Well that's a very helpful answer. However I think it is a transportable unit and not a caravan. What do you think ?

 

[westward10]

717 or 721 are you not still in the same boat, or should I say caravan as the requirements regarding TN-C-S apply in both cases.

 

[Octopus]

What do you think ?

I would have looked at the site to get an idea of what is going on and almost certainly declined the work!

 

[Percyprod]

Static, mobile, shed, non can be pme'd.

 

[Ian1981]

Static, mobile, shed, non can be pme'd.

Why can’t a shed housing Electrical equipment/accessories not be part of TN-c-s earthing.
Care to share your reasoning?

 

[Percyprod]

Not a permanent building

 

[westward10]

Not a permanent building

Is any building

 

[Ian1981]

A well argued answer

 

[buzzlightyear]

made for the trailer trash ,got a tow bar ,has a house !

 

[Sparkingmad]

I have worked extensively in the static caravan park world. The only acceptable earthing arrangements for such buildings is TNS or TT.
TNCS can be used for supply upto external plastic meter box. Unit itself must be connected to earth rod and fed via 30mA RCD. I have also worked on units with SEB TNCS supplies housed in external meter cupboards. We never used the company earth and always fitted earth rods usually one was enough but quite often would fit 2 1 at each end of the concrete base and always tested the metal chassis and side walls to the earth connection.