I have a 230V supply to a small CU in an IP65 box in the garden. This
box has a pump controller (for a well) and an external socket (both
protected by RCBOs) plus an MCB-protected supply (via SWA) to a further
point at the gate. At the gate the SWA enters an IP65 adaptable box
which will have a gate controller and PIR-operated lights connected to
it. The garden CU and the gate each have an earth rod to provide local
TT earthing. I'm using 16mm2 wire and have these
https://www.superlecdirect.com/swa-geb-uk-earth-rod-inspection-box/ at
the top of the earth rods

My questions are: what's the "correct" way to physically connect the
earth rods? Should the wire from rod to box be protected in conduit?
What's the accepted way to take it into the CU and adaptable box while
maintaining the IP65 protection?

On 21/11/2022 19:11, nothanks@aolbin.com wrote:
> I have a 230V supply to a small CU in an IP65 box in the garden. This
> box has a pump controller (for a well) and an external socket (both
> protected by RCBOs) plus an MCB-protected supply (via SWA) to a further
> point at the gate. At the gate the SWA enters an IP65 adaptable box
> which will have a gate controller and PIR-operated lights connected to
> it. The garden CU and the gate each have an earth rod to provide local
> TT earthing. I'm using 16mm2 wire and have these
> https://www.superlecdirect.com/swa-geb-uk-earth-rod-inspection-box/ at
> the top of the earth rods
>
> My questions are: what's the "correct" way to physically connect the
> earth rods? Should the wire from rod to box be protected in conduit?

It does not need to be protected, but the CSA required will vary
depending on if it is. There is a table here:

http://wiki.diyfaq.org.uk/index.php/TT_Earthing#Connecting_to_your_earth

(16mm^2 is going to be more than adequate for any style of installation)

The physical connection is usually a clamp of the appropriate size for
the rod diameter. E.g:

https://www.tlc-direct.co.uk/Products/TLEC58.html

or

https://www.tlc-direct.co.uk/Products/TLEC.html

> What's the accepted way to take it into the CU and adaptable box while
> maintaining the IP65 protection?

A standard compression gland will do the trick:

https://www.tlc-direct.co.uk/Products/EK254B.html

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
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On 21/11/2022 23:42, John Rumm wrote:
> On 21/11/2022 19:11, nothanks@aolbin.com wrote:
>> I have a 230V supply to a small CU in an IP65 box in the garden. This
>> box has a pump controller (for a well) and an external socket (both
>> protected by RCBOs) plus an MCB-protected supply (via SWA) to a
>> further point at the gate. At the gate the SWA enters an IP65
>> adaptable box which will have a gate controller and PIR-operated
>> lights connected to it. The garden CU and the gate each have an earth
>> rod to provide local TT earthing. I'm using 16mm2 wire and have these
>> https://www.superlecdirect.com/swa-geb-uk-earth-rod-inspection-box/ at
>> the top of the earth rods
>>
>> My questions are: what's the "correct" way to physically connect the
>> earth rods? Should the wire from rod to box be protected in conduit?
>
> It does not need to be protected, but the CSA required will vary
> depending on if it is. There is a table here:
>
> http://wiki.diyfaq.org.uk/index.php/TT_Earthing#Connecting_to_your_earth
>
> (16mm^2 is going to be more than adequate for any style of installation)
Thanks, so are there really no protection requirements? It seems odd to
just run a wire over soil so I've tended to put it in "unofficial"
plastic conduit.
>
> The physical connection is usually a clamp of the appropriate size for
> the rod diameter. E.g:
>
> https://www.tlc-direct.co.uk/Products/TLEC58.html
>
> or
>
> https://www.tlc-direct.co.uk/Products/TLEC.html
>
>> What's the accepted way to take it into the CU and adaptable box while
>> maintaining the IP65 protection?
>
> A standard compression gland will do the trick:
>
> https://www.tlc-direct.co.uk/Products/EK254B.html
I don't think they will compress down to the right size for a single
earth wire, hence the question. Silicone works wonders but I wondered
whether there was anything made for the job because I've looked without
success.
>
>

On 22/11/2022 09:54, nothanks@aolbin.com wrote:
> On 21/11/2022 23:42, John Rumm wrote:
>> On 21/11/2022 19:11, nothanks@aolbin.com wrote:
>>> I have a 230V supply to a small CU in an IP65 box in the garden. This
>>> box has a pump controller (for a well) and an external socket (both
>>> protected by RCBOs) plus an MCB-protected supply (via SWA) to a
>>> further point at the gate. At the gate the SWA enters an IP65
>>> adaptable box which will have a gate controller and PIR-operated
>>> lights connected to it. The garden CU and the gate each have an earth
>>> rod to provide local TT earthing. I'm using 16mm2 wire and have these
>>> https://www.superlecdirect.com/swa-geb-uk-earth-rod-inspection-box/
>>> at the top of the earth rods
>>>
>>> My questions are: what's the "correct" way to physically connect the
>>> earth rods? Should the wire from rod to box be protected in conduit?
>>
>> It does not need to be protected, but the CSA required will vary
>> depending on if it is. There is a table here:
>>
>> http://wiki.diyfaq.org.uk/index.php/TT_Earthing#Connecting_to_your_earth
>>
>> (16mm^2 is going to be more than adequate for any style of installation)
> Thanks, so are there really no protection requirements? It seems odd to
> just run a wire over soil so I've tended to put it in "unofficial"
> plastic conduit.
>>
>> The physical connection is usually a clamp of the appropriate size for
>> the rod diameter. E.g:
>>
>> https://www.tlc-direct.co.uk/Products/TLEC58.html
>>
>> or
>>
>> https://www.tlc-direct.co.uk/Products/TLEC.html
>>
>>> What's the accepted way to take it into the CU and adaptable box
>>> while maintaining the IP65 protection?
>>
>> A standard compression gland will do the trick:
>>
>> https://www.tlc-direct.co.uk/Products/EK254B.html
> I don't think they will compress down to the right size for a single
> earth wire, hence the question. Silicone works wonders but I wondered
> whether there was anything made for the job because I've looked without
> success.
Belay that. I just tried a different search and there are plenty
available for smaller sizes - sigh! I seem to have an intermittent fault
with my google fu ;-)
>>
>>
>

On 22/11/2022 09:54, nothanks@aolbin.com wrote:
> On 21/11/2022 23:42, John Rumm wrote:
>> On 21/11/2022 19:11, nothanks@aolbin.com wrote:
>>> I have a 230V supply to a small CU in an IP65 box in the garden. This
>>> box has a pump controller (for a well) and an external socket (both
>>> protected by RCBOs) plus an MCB-protected supply (via SWA) to a
>>> further point at the gate. At the gate the SWA enters an IP65
>>> adaptable box which will have a gate controller and PIR-operated
>>> lights connected to it. The garden CU and the gate each have an earth
>>> rod to provide local TT earthing. I'm using 16mm2 wire and have these
>>> https://www.superlecdirect.com/swa-geb-uk-earth-rod-inspection-box/
>>> at the top of the earth rods
>>>
>>> My questions are: what's the "correct" way to physically connect the
>>> earth rods? Should the wire from rod to box be protected in conduit?
>>
>> It does not need to be protected, but the CSA required will vary
>> depending on if it is. There is a table here:
>>
>> http://wiki.diyfaq.org.uk/index.php/TT_Earthing#Connecting_to_your_earth
>>
>> (16mm^2 is going to be more than adequate for any style of installation)

> Thanks, so are there really no protection requirements? It seems odd to
> just run a wire over soil so I've tended to put it in "unofficial"
> plastic conduit.

It's quite common to see a green/yellow single running out to an earth
rod. The size dictated by the conditions usually (the earth rod
impedance is not usually low enough to make the current carrying
capacity of the wire relevant).

So no harm having it in a conduit etc (and in some cases more
maintainable) but it would be ok without in many cases.

>> The physical connection is usually a clamp of the appropriate size for
>> the rod diameter. E.g:
>>
>> https://www.tlc-direct.co.uk/Products/TLEC58.html
>>
>> or
>>
>> https://www.tlc-direct.co.uk/Products/TLEC.html
>>
>>> What's the accepted way to take it into the CU and adaptable box
>>> while maintaining the IP65 protection?
>>
>> A standard compression gland will do the trick:
>>
>> https://www.tlc-direct.co.uk/Products/EK254B.html

> I don't think they will compress down to the right size for a single
> earth wire, hence the question. Silicone works wonders but I wondered
> whether there was anything made for the job because I've looked without
> success.

I picked that particular gland because it covered wire CSA from 13 to
18mm^2 (ironically I was going to link to the parent page with all the
sizes on).

(BTW, if you a gland from TLC, you need to order the backnut
separately... DAMHIK)

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/