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

 

[timhoward]

Ahh okay so if put in large adapatable box of metal construction next to the consumer unit will that be appropriate.?

Sounds ok to me.
If I was having to sort that out I'd probably go for slightly larger box than that one, longer double insulated tails (supported), appropriate grommet, and solder/crimp, tape and heat shrink the joints inside the box, and dispense with the Henleys.
But just throwing a metal box or trunking around it would achieve the same.

 

[Julie.]

Ahh okay so if put in large adapatable box of metal construction next to the consumer unit will that be appropriate.?

Yes, as long as the cable run has mechanical protection all the way from the one end from the fuse switch through to the CU that would be OK.

Ideally metallic, but plastic can be OK if not concealed

 

[brianmoooore]

Maybe not quite how I ould have done it myself, but the only thing I can see that is non compliant is the lack of a double sheath on the exposed SWA conductors.
If you have any left over 16mm2 or 25mm2 tails, suitable lengths of the outer sheath slid off and slipped over the exposed brown and grey ends of the SWA will do the job.

 

[westward10]

You can't possibly leave it like that aside from looking awful those conductors are not enclosed. No amount of sleeving will make any difference as you will never be able to completely cover them it will always be exposed where they exit the cable. Crimp some 16.0 6181Y within the adaptable box then bring out through a gland.

 

[user786786]

Sounds ok to me.
If I was having to sort that out I'd probably go for slightly larger box than that one, longer double insulated tails (supported), appropriate grommet, and solder/crimp, tape and heat shrink the joints inside the box, and dispense with the Henleys.
But just throwing a metal box or trunking around it would achieve the same.

Great thanks

 

[brianmoooore]

Why will the ends be exposed anymore than the ends of tails when they connect to service blocks at the DNO service end?

 

[westward10]

Why will the ends be exposed anymore than the ends of tails when they connect to service blocks at the DNO service end?

At the cable end which is poking out of the box. To sleeve them the sleeve would have to enter into the cable or it just sits on top.

 

[brianmoooore]

Sleeve should be pushed on all the way back to the SWA gland in the bottom of the adaptable box. I've done this myself to terminate SWA sub mains into flimsy plastic CUs that wouldn't take a SWA gland direct.

 

[buzzlightyear]

The op wins a crackjack pencil for trying.

 

[user786786]

You can't possibly leave it like that aside from looking awful those conductors are not enclosed. No amount of sleeving will make any difference as you will never be able to completely cover them it will always be exposed where they exit the cable. Crimp some 16.0 6181Y within the adaptable box then bring out through a gland.

going to use a large adaptable box . and large trunking . the asethetics are not that important on this occasion as its a garage . i just want to make sure everything is safely carried out to regs .

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