Armoured cable to shed

[FiremanT]

I need to reasonably quickly source armoured cable to run to to a shed, just over 30M.
This will supply LED garden lighting, shed lighting, garden equipment and occasional DIY power tools.
The cable is to run partially under a patio. The patio job is starting in a few weeks, so I need to get the cable and drop the under patio section in when old patio lifted.
I have read that there shoud be 200mm cover - is that correct? Can this be reduced under hardstanding like a patio?

I have looked at suppliers but not being an electrician (and wont be doing the actual work other than running the cable) I am a little confused over the myriad of BS numbers and acronyms! (XLPE, for example). Will 4mm br sufficient, and isnthere any advantage in paying more than the cheapest?

Anything else that I should consider? Nothing will be done on the electical installation until, realistically, the New Year

Thanks

 

[bernardgreen]

First consult with an electrician as to what is neccessary for a safe installation.

Lay in a duct so that the cable can be pulled in after the patio has been laid.

 

[ericmark]

Location is important, the nations of the UK all have different rules, as to what work is notifiable. In the main common sense should prevail, but would ever is going to sign the paperwork has to decide what he/she wants, he/she can agree that some one, be it electricians mate, apprentice, or client does some of the work, but they need to be in control, so you need to as @bernardgreen says, get the electrician involved before you start, a duct seems the best way forward.

 

[FiremanT]

Location is important, the nations of the UK all have different rules, as to what work is notifiable. In the main common sense should prevail, but would ever is going to sign the paperwork has to decide what he/she wants, he/she can agree that some one, be it electricians mate, apprentice, or client does some of the work, but they need to be in control, so you need to as @bernardgreen says, get the electrician involved before you start, a duct seems the best way forward.

England.

 

[ericmark]

Only if a new circuit is the work reportable in England, so using a FCU in house, with 13 amp fuse, and a switched FCU in shed as the light switch with a 3 amp fuse, all work could be DIY.

For lights permitted volt drop 3% so at 13 amp 2.5 mm² over 30 meters is just on the edge, depends on volt drop to the first FCU, however unlikely to have problems with LED lights with volt drop, so for 13 amp supply 2.5 mm² would likely be ample.

 

[Murdochcat]

You say “in a few weeks”

Time to locate a local spark?

 

[FiremanT]

Only if a new circuit is the work reportable in England, so using a FCU in house, with 13 amp fuse, and a switched FCU in shed as the light switch with a 3 amp fuse, all work could be DIY.

For lights permitted volt drop 3% so at 13 amp 2.5 mm² over 30 meters is just on the edge, depends on volt drop to the first FCU, however unlikely to have problems with LED lights with volt drop, so for 13 amp supply 2.5 mm² would likely be ample.

Thats interesting - i thought it was reportable as in the garden. In any case, I would not be confident to DIY, at least not the Armoured cable etc.
The current situation: We have either a 6mm or 4mm (cannot remember which) T&E to an external junction box/housing n the outer wall. This emanates from the house distribution board, protected by a 32a MCB, but NOT on the RCD side
There is Armoured cable (I think 2.5mm) to a shed which is about only 3M away. The AC enters a split distribution board, with RCD, from which garden sockets (2.5mm) and lighting (1mm) were run.
So, by replacing everything from the 2.5 T&E / SWG box, it counts as not a new circuit so no reporting necessary?

Thanks

 

[ericmark]

Thats interesting - i thought it was reportable as in the garden. In any case, I would not be confident to DIY, at least not the Armoured cable etc.
The current situation: We have either a 6mm or 4mm (cannot remember which) T&E to an external junction box/housing n the outer wall. This emanates from the house distribution board, protected by a 32a MCB, but NOT on the RCD side

So far so good, but it means to continue with smaller that 4 mm² there would need to be an overload device.

There is Armoured cable (I think 2.5mm) to a shed which is about only 3M away. The AC enters a split distribution board, with RCD, from which garden sockets (2.5mm) and lighting (1mm) were run.
So, by replacing everything from the 2.5 T&E / SWG box, it counts as not a new circuit so no reporting necessary?

Thanks

The 2.5 mm² in the main limited to 20 amp, this is where there may be a problem.

The Part P regulations were changed in England but not in Wales, so outside and kitchens no longer considered as a special location, only bathrooms remain (England only) it changed from saying what did not need notifying to what needed notifying, however there are many problems with supplies outside, the main one is if protection is needed for loss of PEN which means metal sheds are a problem, wood OK.

It is hard for an electrician of my age (73) to work out what a younger ordinary person would find hard.

Lay in a duct so that the cable can be pulled in after the patio has been laid.

This still seems the best idea. It is what I am going to do when I put up a new shed, so same duct can be used at a latter date if I ever get and EV.