Power supply to garden office question

[crussell1000]

Evening all.

I'm having a garden office installed next week. I work from home so will run a laptop and chargers, lighting, internet router, TV for playtime possibly with an xbox, a music player of some sort. All nothing major.

Now. Last year when I had my house rewired my sparky left a power outlet in the tool shed for me, fed from a 20Amp, rcbo at the board. The run from the out let to the office (so the SWA run) is a shade under 25m (allowing for a little extra flex both ends).

Question is...how many sockets can I go to on ring or radial?

I'll install a sub unit with two MCBs as the circuit is RCD protected at the board in the house.

 

[buzzlightyear]

the extra power that will be installed to the New office need to be part p
my advice is to get spark in .you are over stepping the mark

 

[johnduffell]

Sockets won't be limited and with 20A upstream you wouldn't need a board, just connect the sockets in a radial and lights on an fcu.
The main questions are what size and number of cores in the swa, and what will be the zs and volt drop and earthing arrangements. You would also need to check polarity/continuity/IR and rcd tests. As you probably didn't know that asas above you might want to get the spark back.

 

[buzzlightyear]

To much information may i had .
My advice seek a local spark.

 

[crussell1000]

Well, I'd not bought any SWA yet as I was going to wait for advice until I did.

Its a TNCS PME at the main fuse board.

 

[JAWS]

I take you're an electrican who will be able to test the circu

Well, I'd not bought any SWA yet as I was going to wait for advice until I did.

Its a TNCS PME at the main fuse board.

Hi crussell will it be yourself certifying the install and doing all the relevant testing?

Or is it a case of you installing it all turning it on, it works job done?

 

[crussell1000]

I've had a quote and the spark seems to think its fine running from the existing circuit.

 

[crussell1000]

The total run from fusebox to office is 35m.

I've worked out a total load of 17amps with everything on that I would use.

You think it would be better to use three core SWA from the main CU to the office and have an MCB for sockets and one for lighting?

 

[crussell1000]

The total run from fusebox to office is 35m.

I've worked out a total load of 17amps with everything on that I would use.

You think it would be better to use three core SWA from the main CU to the office and have an MCB for sockets and one for lighting?

 

[The_apprentice2.0]

Any jobs going Telly, Xbox, music player ... in the wrong game me

 

[Spoon]

I've had a quote and the spark seems to think its fine running from the existing circuit.

Get another quote from the electrician for a cable going back to the CU. Then you can decide.

 

[Michael Sands]

No mention of a heater which would be around 13 amps and don’t try and say you don’t need one you definitely will

 

[crussell1000]

Aye that's where most of the current is...2000 watt heater 2000/240=8.3 amps.

Well quotes so far are over a grand...that's a lot more than I anticipated.

So I'm still thinking three core from CU to office. Does it absolutely have to be buried? Or is it OK tto clip to gravel boards along the fencing?

 

[crussell1000]

P.S I'm going to be using a gas heater for most of my heating needs...I prefer it to the dryness in the air that comes from electric heating. I'd worked out the current draw above in the event that I run out of gas and need to use the electric back up

 

[Michael Sands]

Your design current must be done with 230 supply not 240 this will increase your calculations