New Garage CU

[Onoff]

Ran out of pea shingle. Had half a bag of sharp, that'll do. T'other end of the trench where I'm short, I'll have to use ballast.

The blue duct I've just left "sticking up". More digging the other side before I can use that to thread MDPE through.

MUST NOT FORGET THE CABLE TAPE!

 

[Farside]

Don't forget your draw cord(s)!

Not making the mistake of using that horrible blue polyprop rope, either.
Got caught with that stuff. It had been down too long and just fell apart when dragged through.

 

[Onoff]

Not making the mistake of using that horrible blue polyprop rope, either.
Got caught with that stuff. It had been down too long and just fell apart when dragged through.

Going to chance fitting the x2 20mm conduits and x1 SWA into this Boeing Starliner esque cum shuttle thingy, slathering in some silicone grease and shoving it! A long screw will go through to the SWA then the conduits will be taped to it.

Cat-6e will get sucked through with a vacuum cleaner.

 

[OJCar]

Cat-6e will get sucked through with a vacuum cleaner.

Must extract mind from gutter...

 

[Onoff]

Must extract mind from gutter...

And we're through thanks to mine and my lad's patented, 3D printed bell end esque, pushy thing and a good dose of lube. Quite hard shoving it but doable. The 16mm² SWA basically acted like a long, stiff rod.

Mulling now whether to put a 110mm soil pipe in the trench to allow proper kitchen drainage & for services to the garage later on.

 

[RWD3M]

And we're through thanks to mine and my lad's patented, 3D printed bell end esque, pushy thing and a good dose of lube. Quite hard shoving it but doable. The 16mm² SWA basically acted like a long, stiff rod.

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Mulling now whether to put a 110mm soil pipe in the trench to allow proper kitchen drainage & for services to the garage later on.

Absolutely! You'll only regret not doing it later.

 

[Onoff]

The accepted protocol to isolate the armour on SWA if not exporting the earth to an outbuilding is to terminate with an SWA gland into a plastic enclosure before the metal cu in the outbuilding. That to me is a bit ugly.

Terminating in a plastic gland and chopping back the armour isn't the best idea as you can't then access the armour for testing Ze at the end of the SWA.

How about if I terminate the SWA into a normal brass gland but then put that into an M25 to M32 plastic reducer into the metal cu? I'll actually print one from PETG as I've only got BZP ones here. That'll leave the armour available to test Ze.

Like this:

 

[Onoff]

I'm going round in circles with this! Been searching on electrical forums, even been watching John Ward videos.

At the house it's a TT supply. I have a 4' 5/8" rod, an ex DNO earth plate then another 4" 5/8" rod. I'm limited on depth by thin top soil then a flint bed beneath. When I did that about 3 years back and tested it I got 21 ohms which I thought pretty good.

At the garage I'm about to put in a single 4' 5/8" rod for starters. No extraneous conductive elements at the garage.

I have a new, 3 core 16mm² SWA going from the house to the garage from a switch fuse with 100mA Type S RCD.

The distance from garage rod to nearest house rod is exactly 11m. Each then is well outside the other's zone of influence if we assume it's a 4' radius sphere from each.

Is there an issue exporting the earth to the garage via the armour and spare core or should I stop it short as aforementioned?

Thanks.

 

[RaceDiagnostics]

I don't know but I put your question into Gemini 3 and got a very direct response. Connect both ends of the armour and earth wire, it gives a very detailed explanation of why. Given AI can be wrong id put your question into a couple of others to cross check.

Let me know if you want me to paste in what it said.

 

[Onoff]

I don't know but I put your question into Gemini 3 and got a very direct response. Connect both ends of the armour and earth wire, it gives a very detailed explanation of why. Given AI can be wrong id put your question into a couple of others to cross check.

Let me know if you want me to paste in what it said.

Cheers. Didn't think to AI it. Both ChatGPT and Claude say to export as well, again going into depth.

 

[Misterg]

Both ChatGPT and Claude say to export as well, again going into depth.

Jesus Christ! I can't believe people are putting any credibility in these random 'fact' generators for something so crucial.

Here's a qualified electrical Engineer with the answers:

You can't export TT.

 

[MetalMonkey]

You will need an additional earth rod for the outbuilding as you've already established.

I personally don't see any issue with bonding the two together with your SWA - its not really different to how the DNO do it with PME, or if you had a large grid of earth rods.
You are extending the TT system, rather than exporting it, and providing you have a good reading on the rod for the garage it just is a parallel path.

I think perhaps there could be some argument about voltage gradients and extraneous conductive parts, or if the buildings were miles apart you want the rod to be the local earthing – but for 11m in this situation I’d just bond them together.
More earth rods, more better IMO.

 

[Dapph2]

Jesus Christ! I can't believe people are putting any credibility in these random 'fact' generators for something so crucial.

Here's a qualified electrical Engineer with the answers:

You can't export TT.

My local electrical wholesale people now only stock 4 or 5 core STILWA it contains a separate earthing conductor .
They said people are no longer using the galv steel wire as an earth any more . Their head quarters have stopped stocking three core .

It made it easy to get the new cabling in the ground & to the new CU area ( mancupboards floor slab a/w my local yokel to do the shuttering asap )

 

[Farside]

Going to chance fitting the x2 20mm conduits and x1 SWA into this Boeing Starliner esque cum shuttle thingy, slathering in some silicone grease and shoving it! A long screw will go through to the SWA then the conduits will be taped to it.

View attachment 520364

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Cat-6e will get sucked through with a vacuum cleaner.

It's almost like the Bezos dick on a stick.

 

[Onoff]

Jesus Christ! I can't believe people are putting any credibility in these random 'fact' generators for something so crucial.

Here's a qualified electrical Engineer with the answers:

You can't export TT.

I watched that last night. At about 2.50 he discusses TT, shows rodding both house and outbuilding but it didn't answer my question about bonding the two together.

 

[Onoff]

Buried!

 

[Onoff]

Getting there: