When is farm not a farm?

[Oli]

I’m working on a farm, except the barns I’m working in are not being used as agricultural barns, they are rented out for commercial business, workshops etc.
The barns are really one big barn and one CU distributes to all the smaller CU’s in the sub barns. 3 Phase.
The distribution board does not have an RCD , all the sub boards do but none of the distribution circuits have any RCD protection, they are all done with armoured cable, mostly cable tied onto the steel beams overhead.
Should this main board have a 300ma RCD or not?

Cheers for any help guys.

Oli

 

[Moley]

Did someone mention sheep??

 

[sparkdog]

When is a farm not a farm? When its a Macdonalds.

 

[Wilko]

There is a saying "if it quacks like a duck ...". If you're unsure whether it is still an agricultural building, my thought is to have the Owner state the building's use. If they won't say, then it quacks like a duck .

 

[Deleted account]

Armoured cable doesn’t need RCD protection.

Agree, but If it's a TT system and disconnection times are not achievable it would.

 

[Deleted account]

Please disregard above post. It's not a TT system as stated by oil.
Missed that one.

 

[Rpa07]

If you do put a 300ma up front of all those units in use - don’t leave your telephone number for when it trips!
Agree with all the posters above - even @Paignton pete who got a little confused at one point, bless him!

 

[Oli]

If you do put a 300ma up front of all those units in use - don’t leave your telephone number for when it trips!

Care to elaborate on this? I'd like to think that with the 30ma downstream RCD's being fine that the 300 should be ok? but you obviously have some experience of that not being the case.

Thanks for all the advice guys, I'll ask the client for more details.

Oli

 

[Nigel]

Section 705 is for Agricultural and Horticultural premises. This is now neither.

 

[Nigel]

That's generally true, however all circuits in an agricultural installation must be protected by 300 mA RCD.
It doesn't sound like it is an agricultural installation any more though.

Not exceeding 300mA, not 300mA.

 

[Nigel]

A dwelling on an agricultural site is not considered part of the special location and the same can be applied to this.

Except 705.411.4 which states a TN system cannot be used for residences and other locations.

 

[Nigel]

If you do put a 300ma up front of all those units in use - don’t leave your telephone number for when it trips!
Agree with all the posters above - even @Paignton pete who got a little confused at one point, bless him!

The up front should be time delayed. All sockets upto 32A should be 30mA and above 33A should be 100mA. All other circuits should be no more than 300mA.

If designed correctly nuisance tripping should not be an issue.

 

[Nigel]

Care to elaborate on this? I'd like to think that with the 30ma downstream RCD's being fine that the 300 should be ok? but you obviously have some experience of that not being the case.

Thanks for all the advice guys, I'll ask the client for more details.

Oli

If you have lots of circuits all leaking a bit they could accumulate to over 300mA. Like I said if you are relying on a single 300mA RCD to cover all circuits then this would not comply anyway with other Regulations.

All this said Section 705 does not apply anyway.

 

[Rpa07]

I was more joking than making tech speech - it’s what I do, it’s friday and I’m soggy!
@essex came back on all tech info needed, I guess he’s not soggy!

Care to elaborate on this? I'd like to think that with the 30ma downstream RCD's being fine that the 300 should be ok? but you obviously have some experience of that not being the case.

Thanks for all the advice guys, I'll ask the client for more details.

Oli

 

[Oli]

I was more joking than making tech speech - it’s what I do, it’s friday and I’m soggy!

Are you sure soggy is the word, I'd think more like drowned the way today has been.

 

[Spoon]

Are you sure soggy is the word, I'd think more like drowned the way today has been.

I thought that @Rpa07 was going on about his lack of bladder control....