Wiring question

andre_xs

Dear All,
There's a shed in the garden of the house we moved into, and electricity runs into that shed. I've opened the box where the cable comes from (outside the house) and it seems as if the cable to the shed is fed by two cables. I was just wondering whether this is a problem, that the shed is potentially fed by electricity from two circuits? I imagine it some way like a Y-split of the shed-cable and one end connects to one circuit (one fuse in the consumer unit) and the other end connects to the other circuit (another fuse).
No clue why they did this, maybe to get more power to the shed and one line was not sufficient? (the cable running to the shed seems quite substantial) Or they planned to replace one feed and forgot to disconnect the old one (maybe one cable is actually dead, I haven't checked this)?  
With respect to safety, the RCD would probably be unaffected by this I presume? 

mclaren32

Probably more likely that it’s on the ring main which would be a sensible way of doing it, if in doubt get an electrician to have a look though.

FreeBear

Photos of the box & cables ?

Could it be one cable for sockets and a second for lights ?

Try turning off the breakers in the consumer unit one at a time and see if the sockets & lights in the shed are still live. Failing that, get a qualified electrician in to check everything out and make sure it is safe.

Ectophile

It's very unlikely that anybody would feed the shed from two circuits, and it would be wrong to do that.  It's possible that they ran two cables in parallel from the same origin, to reduce the voltage drop.  It's a bit odd, but perhaps they had a spare reel of an under-sized cable.

Another possibility is that you have one wire coming in, and another going out to somewhere else.  Another outbuilding or garden lighting, perhaps.

Heedtheadvice

Using cable to give lots of power to grow some sort of "weed"?

But seriously could be several reasons.....and from what you describe you should not make assumptions that the  "installation" is safe or meets regulations -from whatever period! It does not seem to meet any standard way of doing such an installation.

Maybe best call in an expert rather than rely on educated or uneducated guesses on a forum?

Ectophile

Ectophile said:

It's very unlikely that anybody would feed the shed from two circuits, and it would be wrong to do that.  It's possible that they ran two cables in parallel from the same origin, to reduce the voltage drop.  It's a bit odd, but perhaps they had a spare reel of an under-sized cable.

Another possibility is that you have one wire coming in, and another going out to somewhere else.  Another outbuilding or garden lighting, perhaps.

But having said that, my garage does have two separate feeds.  One powers the lights and sockets in the garage.  The other is only for an outside light.  It's a bit weird, but then much of the wiring in this house seems a bit weird.