outdoor cable woes

[momo32]

Depends on length: as far as we can tell from your description your load is not more than 4kw.

This gives us about 30 metres of 4 core 2.5mm SWA. Though why 4 core? If you are replacing the cable, 3 core 2.5mm would be the answer, assuming the run is less than 30m. Otherwise 4mm.

edit: Though I see your house MCB is rated at 32A, which is too high for 2.5mm cable. I would use 2.5mm and swap the MCB for 20A.

 

[jondiy]

Did I hear you say you have 4 core SWA installed??

Why not send the phase down a spare conductor and sleeve it at either end!

OR!!

If you gland your SWA properly at both ends and use it as the sole earth , that leaves 2 spare conductors (Obviously assuming Zs is acceptable) , you could use those 2 spares as the new phase and neutral conductors - although don't neccessarily need to change them both , as in this case it seems like the fault is only on the phase conductor.


What have you got to loose? Anybody else with me on this??

Admittedly, if the cable is seriously chewed then there may be more than one conductor broken and this method may not work - but then again - it could only be one conductor that has failed!

This is where an insulation resistance & continuity tester would come in very handy!! Do you have anyone who could lend you one?

 

[Spark123]

If the cable is damaged it might not be a great idea to try and use it again, agree with 2.5 being too light. 4mm or even 6mm for future expansion would be better. Also need some blanks in the garage CU .
Will probably be notifiable under part P, (unless your existing cable is also 4mm )

 

[jj4091]

Is the polarity in the garage OK? Sorry just seen pages 2 & 3!!

 

[JohnD]

It must be quite bad damage if it has gone through the armouring and (at least) one of the cores, so probably better not to try to re-use it.

 

[breezer]

be interesting to see the damaged bit

 

[tritonr1]

Why not send the phase down a spare conductor and sleeve it at either end

bingo sent the live down the spare cable and it works....

 

[breezer]

Trouble is that as your swa is damaged, and letting in water (which is why its taken so long to "go wrong") that it will only get worse. you would be better off replacing the cable

(unusual to get a damaged swa but you didnt at first mention the jcb, i would still be interested in seeing the damaged section)

 

[davy_owen_88]

Good to hear you've got it working, but like others have said, the damage must have been quite substantial to go through the armour and 1 of the cores so its probably best that its replaced.

In the mean time, make sure you connect all the unused cores to earth - you don't know what other damage has been done and its not going to take long.

 

[tritonr1]

cheers for all the help guys...this will be a temp measure just for a couple of days...i will then replace the cable with 6mm swa via an alternate route as i don't want to take up the block paving so the old cable will be left in situ

 

[breezer]

dont fix it to the fence

 

[Invisible-Man]

dont fix it to the fence

Why, I have one lke that!

 

[tritonr1]

dont fix it to the fence

i wouldnt be able to bear the site of the cable when i sit out in the summer...
new cable just trails round the perimiter of my fence...when the weather picks up it will be buried..

thanks again for all your help

 

[DESL]

Ok so you've used a spare core to energise circuit but I think it would have been wise to check Insulation Resistance of all cores before energising

 

[Salopiansparky1]

The device in your picture is B32 mcb this operates on over current or short circuit.
The rcd in the picture has not tripped (unless you have reset it).
You need to carry out an insulation resistance test & a load current test
on the cable ffrom the house & and on the sub circuits in the garage