Shed Installation Disconnection time?

[Just]

Hi I have a socket Radial off a 20A MCB and a lighting Radial off 6A MCB in a shed the board is fed by a 32amp MCB protected by an RCD on a TNCS syatem in the house. If I want the first point of fault ie the shed to trip first should I be using an RCBO for a TT system that trips under .2s? This would avoid both RCDs or the one in the house tripping first if I use an RCD 0.4s disconnection. I could change the type of RCD in the house but that protects a number of circuits. I have a 4 way CU so could either have a RCBO main switch, protect two MCBs with a different type RCD or fit two RCBOs. Too many options!
Thanks for your advice,

 

[telectrix]

After all that, if it was me, I'd just drag the house closer to the shed

i'd build an extension to the house, incorporating the shed as a sauna, wet room and , if space permitted, a snooker room complete with bar. open the house as a whorehouse so then it's commercial and parp pee would not apply. as the house would then be turning a profit, i could live in a motor home at the bottom of the garden. all 12v electrics, of course.

 

[RogertheBodger]

What would the disconnection times in the whorehouse be?

 

[telectrix]

all depends on the resistance of the staff, related to the expected turn round, bearing in mind the overheads and profit margin. also not to mention the size of the bondage ( or is it bonding)

 

[Dave_]

Excessive lubrication could be used to ensure the safe release of your single pole device from lucys box

 

[IQ Electrical]

Wow, for a minute I thought I was on my 'other' forum!

 

[Just]

Hi Op back again.... been on holiday can't believe the threads still going! sorry at page 11 couldn't resist. Have to agree with spin as you can't be left in the dark when something in the shed trips the RCD in the house, what if the RCD won't reset? Surely a separate enclosure next to the house CU protecting the SWA and an RCD protecting the CU in the shed is the answer? Now do I need to TT the shed? Dave how do you know my missus?

 

[Deleted member 26818]

I don't believe you would need to TT the shed.
It might work out a cheaper option than installing an appropriately sized bonding conductor if there are extraneous-conductive-parts at the shed which require bonding.

 

[Just]

Fortunately not but good point.

 

[animox]

I was going to post a thread about wiring to a shed, but after those 12 pages I think I'll stick with the long extension lead, RCD protected of coarse.

 

[SirKit Breaker]

I was going to post a thread about wiring to a shed, but after those 12 pages I think I'll stick with the long extension lead, RCD protected of coarse.

Once saw an extension lead powering a shed. It was orange, Black and Decker job 2 core with no earth. Ran from pantry, drilled through window frame, pegged to washing line, and went into shed where all sorts of kit was plugged in. He did a very neat job and even put some sealant in the window frame hole. Pegs at a suitable distance apart to support the cable, and the washing line was one of them polypropolene jobs, nice and tight with no sagging. His face was a picture when i asked him where he thought the earth might be! and an even bigger picture when i told him that if his pond pump did one, he could put a sign up saying Koi Carp frying tonight.

Cheers........Howard

 

[Chr!s]

1st of all the distribution circuit may require RCD protection. Not sure why say for example Reg 522.6.6 and 522.6.7 would not be applicable.

If the distribution is TNCS and there are no requirements for a RCD, then this could be omitted. If the shed is TT then this will obviously require RCD protection.

Regards Chris