livery yard

[Robo]

Im going to be doing some work at a stable yard. Just checking some details before i commence.

30ma rcd on sockets not exceeding 32a
All other circuits 300 ma rcd protection.

Im going to use 30ma rcbo for all circuits.

10mm bonding to extraneous conductive parts and exposed conductive parts.

If the ELI is ok is it still recommended to use a rod as an addition?

Do i have to use galv conduit for the drops or is platic ok?? if the cables are out of reach of horses then i dont need additional protection by means of conduit?

Thanks robo

 

[marksparky]

plastic conduit in agriculture installation, 30ma protection is fine, if ur earth loop impedance is ok y put in another rod? even cables out of reach r recommended additional protection appaently so they dont fall victim to rodents,

 

[malcolmsanford]

Your RCBO's are fine spot on and as your using RCBO's rather than RCD then you don't need to worry about fitting "S" type RCD to non socket outlet circuits that require continuity of services.

If you protect your bonding from mechanical damage and corrosion ie in a conduit you can use 4mm^

If your EFI is fine then no need to add a rod.

This is where I upset all the young'uns in here. As the area is classed as AF4 which is corrosion-continous the conduit should be class 2 for internal and class 4 for external. To me that is class 2 which is black enamel or flo-coat galv and class 4 which is hot dipped galv. I would use metal conduit just for the corrosion and protection as these types of areas can be abused.

Though if plastic is suitable and you prefer that then ok. Metal is just a preference.

 

[Robo]

Thanks for your help guys. I agree class for conduit would be best. Just plastic would be a lot cheaper, and personally i find easier. I will price for both. If I used a twin rcd board instead of rcbos would it be ok to use 1 rcd for sockets and power. And another rcd for lighting and smokes etc?. thanks robo

 

[J@mes]

If by smokes you mean smoke detectors then I would not have them under the same RCD as any other circuits to be honest. Purely because if there was an issue with the battery back-up on them then a nuisance trip on the lighting/ sockets would leave them inoperable, and they are the only way the owners are going to know the place is on fire before it is too late to save the animals.

 

[Robo]

Stable yard. Few queries

Am i right in thinking a 30 ma rcd offers greater protection than say 100ma or 300 ma. If so then im fine to use 30ma protection for everything.

If the house is tncs then its not a good idea to tranport the earthing system to stables so use a rod and dont use earth or swa as a cpc?? But if its a tns or tt im ok to use existing earthing??

Metal conduit is prefered, however if i keep switch and all conduit away from horses say inside the mess room then plastic is ok.

What ip rating do sockets and switches need to be.

Also would you install an emergency lighting or smokes?


Sorry to ask a lot iv been asked to price 2 stables thats all and want to ensure the best way of doing them. Does this come under part P and need a nic eic cert.

Much appreciated guys

Robo

 

[Sintra]

Threads merged.

 

[Sparky Ninja]

Re: Stable yard. Few queries

WOW... questions galore...

Am i right in thinking a 30 ma rcd offers greater protection than say 100ma or 300 ma.

Correct. The 30mA will operate when it detects earth leakage current of up to 30mA. The others, 100mA & 300mA will require 3.3 and 10 times more to operate. (Approximatley)

If so then im fine to use 30ma protection for everything.

Yes, but do take discrimination into account.

If the house is tncs then its not a good idea to tranport the earthing system to stables so use a rod and dont use earth or swa as a cpc?? But if its a tns or tt im ok to use existing earthing??

I'm not sure as to how closely related the stable can be considered as agricultural. Seeing as there is livestock I assume it's justified. In this case, yes you would want to avoid using TNC-s as you will be likely to have high perspective fault currents, and will be unable to provide effective bonding to achieve low enough touch voltages.

Metal conduit is prefered, however if i keep switch and all conduit away from horses say inside the mess room then plastic is ok.

If's it's away from great impact then yes. You may want to consider the temperature also though, if the PVC conduit is exposed to very cold nights, and people putting the heating on in the winter days, it will likely warp.

What ip rating do sockets and switches need to be.

IP44

Also would you install an emergency lighting or smokes?

Of course

Does this come under part P and need a nic eic cert.

If the installation you are to work on is on the same metered supply as anything to be considered domestic, then notification will be necessary.
It will need a cert, any electrical installation work needs necessary certs to be completed. Does not mean they have to be NICEIC though.

 

[malcolmsanford]

Great answer Widdler agree with all. If Robo is going to run a sub main to a new CU in the stable, That sub main is classed as either TN-S or TT, so therefore the new installation would not be TNC-S.

But it may all be mute as the DNO may not let you export the earth outside. They do this for the very reason as above. He may find he will have to TT this stable.

 

[Robo]

Top answer widdler, thanks mate, Thanks for your help to malcomsanford. The earthing is the only suspect part? malc are u saying if the supply to house is tnc-s and then i connect a sub main to that then it will b and tns?? Either way i think TT is safest option.

 

[Jurassic Sparks]

just a few odd notes on the subject
Horses and Horse food= rodents
I used to work for a large construction company and one of the directors had a livery stable built and used lots of plastic conduit, guess who was called out to check the reason for faults??
the rats head eaten the conduit and any exposed cable
I work in the sticks so I always you metal conduit galvanised as horse wee is acidic
other thing to check for if using TT systems are gradients, animals are very susceptible to small voltages if you have any current leaking away and any gradients present our four legged friend crossing them will detect it by promptly dropping dead
and they aint cheap to replace
we were always advised to installs the rods in pits at some distance from the buildings
also be careful of leads when working no 240v tools and even 110v stuff will top a horse if he puts his huge hoof with metal conductor across it
they have a special bit in the 17th about agricultural buildings I seem to recall
and using 30Ma for all circuits is good judgement
a good stud horse can cost a quarter of a million
good luck
jurassic

 

[malcolmsanford]

Top answer widdler, thanks mate, Thanks for your help to malcomsanford. The earthing is the only suspect part? malc are u saying if the supply to house is tnc-s and then i connect a sub main to that then it will b and tns?? Either way i think TT is safest option.

Regulations under the 543.4 section give you details of this. 543.4.1 tells that only under certain conditions, a PEN systems can be extended into an installtion. This is further outlined in the ESQC-2002 regulation 8(4) where it is actually prohibited and that unlike the regs is law.

Bottom line you can not use a PEN within an installtion unless you meet certain criteria.

Reg 543.4.9 tells you what to do after you seperate the PEN. When you run your sub main you are going to be using a different bar for earth and neutral, it then becomes a TN-S, so your livery stable becomes a TN-S system with a seperate earth and neutral.

This is why the DNO do not like you exporting the earth on a TNC-S system. Personally after contacting the DNO they will tell you if you can export or not. Personally I would TT the livery stable.

 

[johnboy6083]

just a quick one, i would install IP65 sockets and switches, as stables are likely to be hosed down occasionally.

 

[Robo]

went to see the job today lads. Not as straight forward as the poor ladyy had thought.
The stable is 60m from the garage where the new swa has already been laid. This fuse board is pre historic lol. So that needs replacing. And the garage is conected to the house by a 2.5 spur of the house sockets. House db is also ancient.

Was gonna do fuse board change in house. Run a new 10mm swa or TandE from house to garage. Have this on a 50a mcb on the unprotected side or use time delay rcbo??. (deals with rcd discrimination). New db in garage for light and socket and Have a 32 a feed for stable. Again either on unprotected side?? or on time delay rcbo. Then a small db in shed next to stable for lights and socket. plus use a rod for this db.

This all sound cushty or any1 got any better ideas. thought of splitting tails so houses is totally seperate from garage and shed. This will all b nic eic signed off.

 

[malcolmsanford]

Your going to have to tread very warily if your using this as your Assement, espicially if your going to use that SWA out to the stable, as really you can't fill in a EIC as you can't confirm how it was installed, and the assessor will pull you on that, or he should. Unless you fib a little and it looks like a brand new piece of SWA

As it's a 60 metre run I would be astonished if the DNO let's you export the earth, so TT the livery stable. Also that will make the bonding of water at the stable easier as you can use the CU earth bar as your bonding point as that will be the MET for your TT circuit.

If the existing CU is that old then don't bother to touch it you can unearth all sorts of problems. Henley block the main tails and fit a little 2 way board for the garage and the stable. If the SWA is 3 core then you won't need to RCD the sub main as your going to use the 3rd core of the cable as your CPC, if it's only a 2 core and your using the SWA as your CPC then you will need to RCD as it comes under reg 522.6.5

60 metres is a decent run so your going to have to be spot on with calcs for loading and volt drop, as it's your assement make sure you are as the assessor will ask you how you calcualted the cable and the laoding. As the SWA is already there you can only work with what you got.

Why are you thinking of a 50amp supply for the garage that is as much as a small house!. All you need for a garage really is a 6amp for lights and 20amp for a 4mm^ radial. If there is going to be a larger load usage then perhaps think of a ring final circuit or a 4mm^ 32amp radial. so a maximum for a garage I would use is a 40amp and in most cases a 32amp, then depending on how long the run is, and what erection method you use, a 32amp 6mm^ should be ample.