New sub board for shed swa advice.

[Jcamerz]

Hi guys new to the forum after bit of advice. My family are installing a new shed in the garden and require a lot of power ie few sockets, lights. I am planning of running a swa fed from 32a mcb from the main board to a sub board.
Have a question-
Shall I install the new 32a mcb in the main board on the RCD side or main switch side?
Thanks

 

[johnduffell]

earthing the armour at the downstream end is OK but it would slow down the disconnection time for faults near the origin. and hopefully no extraneous conductive parts in the outbuilding?

 

[Gavin John Hyde]

I might be wrong but im assuming the op is not an electrician as some of his replies are lacking even basic knowledge.
I am surprised the thread is open still as i can see it turning into us designing the whole job.
No mention of how he is getting this signed of by an electrician of bc to comply with part p either

 

[Jcamerz]

Im still in training at the moment this is all new to me, my family will be getting in a local spark but im intrigued to learn the installation method. Thanks for the comments

 

[sparksburnout]

Im still in training at the moment this is all new to me, my family will be getting in a local spark but im intrigued to learn the installation method. Thanks for the comments

"I am planning of running a swa fed from 32a mcb from the main board to a sub board." ????

 

[telectrix]

View attachment 43319

that's no use there's no hole for the gland.

 

[Gavin John Hyde]

"I am planning of running a swa fed from 32a mcb from the main board to a sub board." ????

@sparksburnout makes the case for the prosecution

 

[johnduffell]

earthing the armour at the downstream end is OK but it would slow down the disconnection time for faults near the origin. and hopefully no extraneous conductive parts in the outbuilding?

@netblindpaul since you pressed Disagree, I'm looking forward to your explanation or edit did you mean you have to earth from the head end?

 

[netblindpaul]

@netblindpaul since you pressed Disagree, I'm looking forward to your explanation or edit did you mean you have to earth from the head end?

Yes, you must connect the SWA to the installation earthing system at the supply end.
You should see that when you do your design FMEA.

 

[Octopus]

Yes, you must connect the SWA to the installation earthing system at the supply end.
You should see that when you do your design FMEA.

Reg number please

 

[johnduffell]

Yes, you must connect the SWA to the installation earthing system at the supply end.
You should see that when you do your design FMEA.

I'm not an electrician but do you mean the physical connection must be at the supply end, or just that the armour has to be connected to the earthing system that protects it?
I guess you're suggesting if the cable is cleanly cut quickly enough (5s disconnection time) it may leave an unprotected live conductor physically separated from the cpc that protects it, and possibly shorted to the now floating armour.

 

[netblindpaul]

Reg number please

Regulations 3, 4, 7, 8, & 9

 

[netblindpaul]

I'm not an electrician but do you mean the physical connection must be at the supply end, or just that the armour has to be connected to the earthing system that protects it?
I guess you're suggesting if the cable is cleanly cut quickly enough (5s disconnection time) it may leave an unprotected live conductor physically separated from the cpc that protects it, and possibly shorted to the now floating armour.

One potential failure mode yes.

 

[Octopus]

Regulations 3, 4, 7, 8, & 9

That I simply do not believe .....

 

[Dave OCD]

There are occasions when earthing the armour [when a seperate cpc exists in the cable] can only be carried out at the 'load' end and I can't see any reason why this is detrimental to safety when done correctly. I wish people would stop posting misleading nonsense.

 

[sparksburnout]

There are occasions when earthing the armour [when a seperate cpc exists in the cable] can only be carried out at the 'load' end and I can't see any reason why this is detrimental to safety when done correctly. I wish people would stop posting misleading nonsense.

What are these occasions then?