Horse stable. would you TT or TN-S ?

[1Justin]

This is not quite “Agricultural and Horticultural”, - but has horses!
DNO supply to an outbuilding (just a craft room, no animals). TN-S at head.
This feeds metal clad barn containing horse(s). About 20M away.
No metal floor grids, no other metal other than the cladding and local CPC's from lighting/sockets.

Might you recommend TT the barn? or stick with the TN-S?- There is NO CHANCE of an underground SWA (too much concrete). Existing overhead catenary support can be re-used, (ex. installation is unsafe - I could go into why but not much point here).

 

[GLENNSPARK]

go for TT....is the stables metal framed?

 

[Engineer54]

No bonded earthed floor grid, then it needs to be a TT system, but how are you going to achieve that if the surronding area is all concrete. Sound like you're going to have to do a bit of concrete breaking, whatever you do...lol!!

 

[GLENNSPARK]

how high up is the catenary?

 

[GLENNSPARK]

No bonded earthed floor grid, then it needs to be a TT system, but how are you going to achieve that if the surronding area is all concrete. Sound like you're going to have to do a bit of concrete breaking, whatever you do...lol!!

if the stables is metal framed...cant he use that?

 

[GLENNSPARK]

sorry...just re-read that its only the cladding thats metal..

OK Justin...as eng says...get breakin.....go in with 3X 5/8" rods...couplers to suit...

 

[telectrix]

good point. needs to be at least 12ft. to be out of reach of nag's gnashers.

 

[Knobhead]

Make it lower. I hate horses!

Not bad served with a good red wine sauce though.

 

[GLENNSPARK]

Make it lower. I hate horses!

Not bad served with a good red wine sauce though.

you been on them dodgy burgers from the bootsale again Tony?

 

[Knobhead]

Ten toes and only 7 intact, you wonder why I hate horses?

 

[GLENNSPARK]

yep..i can imagine why your a bit hoofed off at it all...

 

[1Justin]

The catenary is 3.8M at it's lowest. Granted it's lower than 6M for "agricultural", but They claim they have no problem with their (small) horse box access and no other machinery uses it as far as I'm aware.

 

[1Justin]

Hi Glenn,
Yes only the roof and two of the walls are metal. There are places with soil not concreted so i could go in there I guess.

 

[1Justin]

Thanks for the inputs, I think TT is the way to go then. I did also speak to DNO since it was hard to identify the head. (Concentric type cable with - as it turns out - separate earth). DNO suggest no probs with exporting to stable, but I'm inclined to take the TT line.

(I didn't add that the ex. installation is on the catenary with T&E). I just went again for some more measurements (isolated it first time round). R2 across the gap is 1Kohm. 4MM cable abraded by wind flapping about where it punctures the metal shed.
Stable girl said the bangs were "like a gun" during the windy weather. - This was all extra exciting because the T&E was wired directly into the TOP of the main switch

 

[Engineer54]

Thanks for the inputs, I think TT is the way to go then. I did also speak to DNO since it was hard to identify the head. (Concentric type cable with - as it turns out - separate earth). DNO suggest no probs with exporting to stable, but I'm inclined to take the TT line.

(I didn't add that the ex. installation is on the catenary with T&E). I just went again for some more measurements (isolated it first time round). R2 across the gap is 1Kohm. 4MM cable abraded by wind flapping about where it punctures the metal shed.
Stable girl said the bangs were "like a gun" during the windy weather. - This was all extra exciting because the T&E was wired directly into the TOP of the main switch

So it's NOT a PME installation at all then, which i mistakenly took that it was!! The concentric cable you describe above is called a ''Split Concentric'' cable, used by the DNO for TN-S. If that's correct, then there would be no problem extending the equipotential zone to the stable.... It's only within a PME earthing system where it could cause problems for livestock!!