Wiring in a Metal shed

[f49h]

Hi Guys
I am replacing my wooden shed to a metal shed.
I have already have electric in the shed.
This is from my main ELCB thro a 16amp mcb, to a switch.
On the other end of the switch is 10mm dia armour cable.
This runs to the shed approx 24m. It is connect to a consumer unit
16amp and 5 amp mcb. I have a light in the shed and two sockets which is for drills, pond pump etc. The earth is back to my ELCB

Can i just change over the consumer unit or would there be an earthing issue because the shed is metal.

Cheers

 

[Steve]

This is from my main ELCB thro a 16amp mcb, to a switch.
On the other end of the switch is 10mm dia armour cable.
This runs to the shed approx 24m. It is connect to a consumer unit
16amp and 5 amp mcb.

I find it extremely hard to believe that someone would throw in 10mm² armoured cable for a 16 amp supply, when the cable could carry 50 amps.

4mm² or even 2.5mm² SWA could be ok for a 16 amp supply, and would be a fraction of the price!

Are you SURE its 10mm²? Can you get us a photo of one end of it, with its terminations exposed?

 

[f49h]

I think it what was left from my mates previous job, I measured the dia.
I'll try and get a photo.

 

[ColJack]

is that total, each core including insulation, or just the copper bit of the core?

 

[f49h]

It the total , the od of the cable

 

[Spark123]

Your ELCB could be a voltage operated one which is well past due renewal - can you post a photo of it?

 

[f49h]

It is a MEM Memera 21
How do you upload a photo[/list]

 

[Adam_151]

if its really 10mm OD diameter can't be more than 1.5mm² armoured!... though what are you using to measure the OD... if you are saying 10mm as in it looks somewhere around 10mm on a ruler, then you arn't being precise enough... for example one manufacturs 2.5mm² 4-core measures 13.6mm OD and the 4mm is 14.9mm² (from memory)

 

[ericmark]

Earthing is not so simple. Because you now have an extraneous-conductive-part you need to ensure that does not have more then 50 volts between it and earth. If the shed is well away from the house it would be better to use a TT system but if items powered from the shed can get close to the house then it need to be on same system as house.

To use both house earth and an earth rod with a PME supply to house the earth cable needs to be at least 10mm². Looking at the details for XLPE/PVC/SWA/PVC (Copper) BS5467 cable 1.5mm² 2 core is 12.3mm diameter details from Batt cables web site. So the cable you have feeding the shed is not big enough to duel earth so has to be either TT or TN-S and since the shed its self is an extraneous-conductive-part I would say likely it will need to be TT (i.e. earth rod).

To install an earth rod the rod will need testing and the meters used for this are very expensive so I would say it’s not a DIY job.

You can approach the LABC and ask them of course and they may allow DIY but they charge £100 plus vat and if it fails there may be an extra charge to re-test.

As to ELCB this term is used for both voltage and current units now we are only allowed current units which will need to be 30ma at 40ms.

I know you don't have Part P but there is something similar maybe one of the sparks north of the boarder can tell you procedure.

 

[f49h]

cheers everyone,
i'll look into it

 

[davelx]

You can approach the LABC and ask them of course and they may allow DIY but they charge £100 plus vat and if it fails there may be an extra charge to re-test.

I wish! Mine charges £300 and requires you to organize & pay for the EIC yourself (yes, I know all about what AD P and the ODPM Letter say about that).

 

[ban-all-sheds]

I find it extremely hard to believe that someone would throw in 10mm² armoured cable for a 16 amp supply

They didn't:

On the other end of the switch is 10mm dia armour cable.

Are you SURE its 10mm²?

He never said it was:

On the other end of the switch is 10mm dia armour cable.

 

[ban-all-sheds]

I am replacing my wooden shed to a metal shed.
.
.
.
Can i just change over the consumer unit or would there be an earthing issue because the shed is metal.

Whatever you do the risks will be infrequent, as you'll only be able to use the shed for a few months of the year.