External Termination of SWA

[monday]

I have an swa cable which originally fed a shed. The shed has given way to a new patio and I want to re-terminate the SWA to feed some 12-24v DC patio lights, an external socket and a 240v floodlight to an adjacent utility area.

The SWA was previously terminated to a metal clad socket inside the shed. The new termination needs to be external at a box on the house wall (this will be "round the corner" from the patio, so out of sight). Can I terminate to (eg) a Masterseal double socket and then spur off (in T&E in conduit) to a weatherproof enclosure for the lights transformer and to the floodlight, all glanded out of the box? Is the standard SWA gland acceptable for this purpose as in spite of the shroud, the metal work is exposed to weather? Does the gland banjo need a separate earth connection - it is 3 core SWA.

The SWA originates from the RCD side of the CU.

 

[ban-all-sheds]

Can I terminate to (eg) a Masterseal double socket

Yes.

and then spur off (in T&E in conduit) to a weatherproof enclosure for the lights transformer and to the floodlight, all glanded out of the box?

Why on earth would you not continue to use SWA for that?

As for "spur off", whether you may do that depends on where the circuit originates. If it's a dedicated radial, just extend it using appropriately sized cable.

• http://www.google.co.uk/search?q=cable+installation+methods+17th+edition
  
  
• //www.diynot.com/wiki/Electrics:MCBtoCable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• http://web.archive.org/web/20070327014113/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.batt.co.uk/upload/files/4d5.pdf
  
  The references above which are in italics are out of date. The principles are still valid, and you can absolutely learn valid things from them, but you will need to refer to the latest edition of the Wiring Regulations to get the correct data.
  

If it's already a spur then you'll need to put an FCU at its origin.

Is the standard SWA gland acceptable for this purpose as in spite of the shroud, the metal work is exposed to weather?

CW glands are fine - it's what they are made for.

Does the gland banjo need a separate earth connection - it is 3 core SWA.

Of course - how else do you think the armour will get earthed? But ditch the banjos and use earth nuts.

//www.diynot.com/wiki/Electrics:SWA_gland


What are you planning to do about testing for continuity, polarity, insulation resistance, fault loop impedance and RCD functioning?

 

[ericmark]

I have no idea of your skill so as to if you can do it I don't know. But to construct some sort of shelter and have a number of outlets is clearly possible. What you want is a way to protect from wind driven rain. This could be a plastic enclosure or some wooden construction like a bird table.

 

[monday]

Thanks for responses:

BAS - my main concern was external use of SWA gland, therefore reluctant to use two more to extend beyond the Masterseal socket. But if such use is OK then I am happy to continue the SWA. Useful tip re piranha nut - obviously I need to earth the armour, getting confused with the previous metalclad socket.

Ericmark - the location is quite sheltered so weatherproof box should be OK, concern was with the SWA gland, I have never used one externally before.

Thanks again.

 

[Adam_151]

my main concern was external use of SWA gland

You need to ensure that you use external glands (CW), rather than internal (BW)

Good practice is to avoid top entry to enclosures... a lasting watertight seal can be promblematic with them. Ideally base entry is perfered, with side entry accepted if necessary.

Use earth nuts to ensure all sections of SWA have the armouring earthed... its easier than messing around with banjos on IP rated enclosures

 

[Risteard]

A banjo on a plastic enclosure would need to be sandwiched between two locknuts inside the enclosure. This is to prevent plastic creeping.

 

[monday]

Adam_151/Risteard - Thanks both. I'll use CW glands and piranhas as suggested by BAS.