Log Cabin Power

[Spark123]

If it is a metal CU then I'd go straight to the consumer unit with the SWA.
If it isn't then you can still get away by using a metal adapatable box directly next to it the CU - if it is indoors then there's no real reason to use an IP66 box unless it is going to get wet.

 

[meno]

i have the ip66 boxes already thats the only reason.

ill go ip66 outside with the tail thru wall into small cu if thats ok

cheers

 

[Spark123]

It is acceptable to do it that way, the only issue you have with using a plastic box is how to connect the SWA armour to the CPC. Using something like a piranha locknut or using two locknuts inside the box to sandwich the banjo are two ways I'd consider. Then there's the connection to the consumer unit to consider, i.e. the inner insulation of the SWA isn't afaik classed as a cable sheath so will need run in a conduit etc if going direct or joined to the twin and earth and then run to the CU, ensuring the twin and earth is protected.

 

[meno]

thanks for your help, but im getting more confused:

this is what i have:
6mm 3core SWA
6mm T&E
IP66 box x2
Garage CU

28mm Timber Wall in cabin

Brick cavity house wall

Hows best?

Many Many Thanks

 

[Spark123]

You can use SWA between the two IP66 boxes and twin + earth between the boxes and the CUs. This will mean joining the twin and earth to the SWA in each IP66 box, you also need to ensure the armour of the SWA is earthed by correctly using a banjo or a piranha locknut. I don't know how much room there is inside those IP66 boxes, it might be a little bit tight.

 

[meno]

thanks thats what i originally planned, just concerned about the T&E coming out the bottom of the box and into the wall (in the open unprotected). would it be better to go thru the back of the box thru the walls and seal the box against the wall?

Do i need special glands for the flat T&E or just the box grommet?

I have put a gland in the box, yes its a bit tight but ok.

Many Thanks

 

[Spark123]

The important bit is the gland needs to connect the armour to the protective conductor. There is often a banjo included in the kit for this however only a single locknut is normally provided. I don't like seeing a banjo sandwiched against a plastic box, a piranha locknut is better.
Best not to run the twin and earth out of the bottom, straight out of the back and through the wall. Seal any holes with silicone, leave a small hole in the bottom so if any water does get in it can drain out.

 

[meno]

many thanks for your help, thats what i will do then.

i have a couple of spare locknuts so i can sandwich the banjo.

cheers, just waiting for the rain to stop so i can crack on!

 

[ban-all-sheds]

IP66 box x2

Oh dear.

There isn't room inside those for the locknut of a SWA gland, let alone a Piranha.

You'll need a different sort I'm afraid....

 

[ban-all-sheds]

Do i need special glands for the flat T&E or just the box grommet?

I'd advise a proper flat cable compression gland, despite their ludicrous price.

I have put a gland in the box, yes its a bit tight but ok.

You actually managed to get the locknut tight enough to maintain a watertight seal?

 

[ban-all-sheds]

Best not to run the twin and earth out of the bottom, straight out of the back and through the wall.

A hole in the back can let water in.

One in the bottom with a drip loop in the cable can't....

Plus at the sides those boxes have threaded holes for glands, and inside there's a terminal strip which makes a rear hole awkward:

 

[Spark123]

Putting it in the bottom will leave the twin and earth exposed to damage. I see what you mean by the box not being brilliant for access to the back. Does the terminal rail unclip? If a hole was to be made good again with silicone sealant then it shouldn't let water in, but I'm erring on the side of it being better to run the SWA directly to the CU.

 

[ban-all-sheds]

Putting it in the bottom will leave the twin and earth exposed to damage.

True.

No need for T/E anyway - if taking the SWA through the wall isn't OK then I'd probably run TRS flex from the box, or flexible conduit with the SWA cores inside.

Does the terminal rail unclip?

It does, but what you can't see very well from the photo is that the back has a matrix of a dozen or so blind holes into which the rail plugs - it has two round lugs on it, and it can be mounted centrally or offset, vertically or horizontally or at 45°, and drilling could be awkward.

If a hole was to be made good again with silicone sealant then it shouldn't let water in,

I'm just dubious about the long-term integrity of silicone, particularly outside.

but I'm erring on the side of it being better to run the SWA directly to the CU.

I agree.

 

[Spark123]

It isn't outside outside as in exposed to the elements, and it keeps the water inside my fish tank But as you say the back doesn't appear to be suitable for drilling so probably isn't worth the hastle.
That pic one of yours Ban?

 

[ban-all-sheds]

It isn't outside outside as in exposed to the elements

Meno's will be - one box on the outside wall of the house, on on the outside of the shed...