Protection for wooden summer house

Npt88 · Oct 23, 2012

Evening all,
Just got a few ideas for a job I'm doing to run past you's.
Been asked to wire up a wooden summer house and I priced and got the job but just had an after thought as he said he was planning to use plywood to board it instead of plasterboard. Should I instead of 30mA be installing 300mA as sockets etc will be mounted in wood?
Bit of background on the job.
4mm SWA feed to it via a 32a mcb
2way DB inside the summer house with rcd main switch.
Sockets etc wired in t&e inside cavities in walls.

Thanks

Sintra · Oct 23, 2012

Absolutely not where did you get that idea from?

Npt88 · Oct 23, 2012

Fire protection? Have I got the wrong end of the stick there?

Sintra · Oct 23, 2012

Yea I think you have the maximum RCD you can use on socket circuits and for cables concealed in walls etc is 30mA. The 300mA for protection against fire is generally only used on sub mains in agricultural installations.

Npt88 · Oct 23, 2012

AGRHHHHH I see. Learn something new everyday and all that

Cheers mate

Engineer54 · Oct 24, 2012

Dear, oh dear, oh dear, ....Think about just this, for a second or two Npt88. ...If a 300mA RCD offers a fire protection level of protection, would not a 30mA RCD not be providing an even better fire protection level?? And that's before we consider all the other benefits of 30mA protection...

High Tower · Oct 24, 2012

How far away is the summer house, have you given any consideration to volt drop?

Npt88 · Oct 24, 2012

haha oh dear i really wasnt thinking straight there! God i dont half know how to make a fool of myself!
And yeh iv done my calcs and all works out hunky dory
Cheers

ROADESPARKY · Oct 25, 2012

300 is more than 30 must be better!!!!!<>~{|\]{}#%%**$€>>~|}#%%

Npt88 · Oct 25, 2012

Yes I know as I said above. I actually don't know what I was thinking ha One of those moments!

lauriehurman · Oct 26, 2012

422.3.9 Locations where a particular risk of fire exists - Locations with risks of fire due to the nature of processed or stored materials - 300mA
532.1 (1) Devices for protection against the risk of fire - 300mA
Both of these refer to materials and processes that are inside buildings.

422.4 covers wooden buildings and doesn't mention RCDs.

Agricultural premises (since you mentioned them) 705.411.1 Final circuits supplying sockets < 32A, 30mA. Final circuits supplying sockets > 32A, 100mA. All others 300mA.

Laurie