SWA too short !

[user786786]

Hi
Fitting a consumer unit in garage . Unfortunately the 16MM SWA is too short to reach consumer unit
So i have done as follows .

Glanded SWA into a metal adaptable box .
earthing nut earthed with 10mm crimped and run to earth block .
2 cores of SWA Brown and Grey ( oversleeved BLUE) run to single pole Henley blocks
25mm LIVE and Neutral tails to consumer Unit main switch through Same 32 mm hole
3rd core of SWA ( oversleeved earth ) to earthing Block in consumer unit .

Everything is being boxed over ( acessable ) so the single insulated cores of SWA will be covered.

Does this seem ok?

Also at the supply end is it okay 25mm tails from henley to 100amp double isolator to feed swa after glanding in a adaptable box .
Thanks

 

[westward10]

Aesthetics are always important.

 

[loz2754]

Aesthetics are always important.

Professional pride too.

 

[pc1966]

Aesthetics are always important.

Often they follow from a job well done.

 

[Darkwood]

I will add a few points in addition to others concerns of exposed single insulated cables.

You tell us the supply is TN but what I was getting at is whether is is TNS or TNCS, this can matter, it may mean you garage requires equipotential bonding installed or isolation from electrical earth and rodding as a TT set up.
-Do you have a metal structure or support to the garage that is attached to the ground?
-Do you have any metallic pipes like service pipes (gas - water) coming up through the ground into the garage?

If the answer is yes to any of these questions then you may need to take specific measures in your earthing arrangements in the garage.
To note here that this will not be a concern if the garage is structurally part of the house and not a separate entity away from the house itself.

 

[user786786]

I will add a few points in addition to others concerns of exposed single insulated cables.

You tell us the supply is TN but what I was getting at is whether is is TNS or TNCS, this can matter, it may mean you garage requires equipotential bonding installed or isolation from electrical earth and rodding as a TT set up.
-Do you have a metal structure or support to the garage that is attached to the ground?
-Do you have any metallic pipes like service pipes (gas - water) coming up through the ground into the garage?

If the answer is yes to any of these questions then you may need to take specific measures in your earthing arrangements in the garage.
To note here that this will not be a concern if the garage is structurally part of the house and not a separate entity away from the house itself.

Hi

it is seperate at back of garden . No metalic structure /support to ground .
no metalic pipes only a plastic MDPE water pipe.

The electrician who did the intial 1st fix work didnt ask to get a steel rod on the shopping list he left me .So i am assusing that he is using the main earth supply via swa 3rd core

I will confirm with the electrcian when they come to energise and test the installation /supply as i dont have knowldge of testing and havent invested in the equipment yet .

Is there a way to distinguish between TNS or TNCS or is it only via testing ?

thanks

 

[Darkwood]

Confirm it with the Electrician, I didn't realise you were in tally with an electrician, don't worry about the supply characteristics then as this should have also been taken into account by your electrician, in hindsight it would have been better to get them in to do the extended joint as in its present state it would not comply as others have mentioned.

 

[brianmoooore]

The CPC and neutral are connected to the same block of brass in the DNO service head on a TNCS system, so any Ze you measure at the CU will be just the resistance of the two tails, which for a 'normal' set up will be very close to zero.
On a TNS system, the connection point between the two is further back the line, so you should be able to measure a significant resistance.