Calling fellow sparks

[Barryscott]

I haven't done many agricultural installations before so does this set up seem ok?
The building is steel framed with a water supply

Pig sty/weighing room is fed from separate building 50mtrs away which has a PME head. The plan is to have a switch fuse feeding an two core swa, then an insulating gland on DB with earth rod (making aTT system) with a 300ma time delayed rcd main switch and 30ma on socket outlets not exceeding 32amp
There is two other pig stys each with there own DB that I will feed with a 30ma rcbo.
Lighting, feed system etc will be protected by the 300ma rcd
Water and steel will both be bonded to the DB

Is the 300ma ok or would a 100ma be better for the little piggies

 

[JohnW2]

Is the 300ma ok or would a 100ma be better for the little piggies

As a passing comment, I don't think that either would be of much use in protecting the life and limb of any animal, human or otherwise, who found themselves as a path between L and E - few would survive a sustained shock current of, say, 90mA (too low to reliably operate either of the RCDs you mention). Such RCDs are present for reasons other than limiting the duration of shock currents through living creatures!

Kind Regards, John

 

[flyingsparks]

300mA is fine, regs state a max of 300mA protecting agricultural supplies. I would go for type S or time delayed rcd's. I guess you will be using the steel work of the building as your earth electrode?

 

[flameport]

There is two other pig stys each with there own DB that I will feed with a 30ma rcbo.

Those will need to be double pole versions.