17th Edition CU's

[b33k34]

Can anyone clarify exactly what changed in CU's for 17th edition?

There seem to be for sale CU's that are marked as '17th edition' and those from the same manufacturer that *seem* to have identical features but are not (older stock or something more?)

What would be wrong with a modern Wylex split load box with both sides protected by RCB's that's not marked 17thEd?

 

[ricicle]

Nothing.

 

[ban-all-sheds]

You need to read 314.1 and 522.6.7

 

[b33k34]

ricicle - thanks

ban-all-sheds - no thanks. I'm fully aware I could buy the regs and try to decipher them but the reason i've asked on an internet forum is because I'm hoping to get an answer.

Of course I could just be a sucker looking for personal abuse in which case I've probably come to the right place. A very odd forum this one.

 

[pjcomp]

Strictly speaking there's no such thing as a "17th edition CU" - mainly a marketing ploy by the manufacturers. The regs have made it a requirement that (to paraphrase simplistically) domestic installations must be fully covered by RCDs; to meet the requirement for full RCD coverage but avoid switching off all circuits at once, the dual-RCD board was born and dubbed the "17th edition" board. But there are other ways of meeting the RCD requirements of the regs, and a sparks who knows his trade can decide for himself how best to do that; the dual-RCD board is just one option.

PJ

 

[PrenticeBoyofDerry]

There are also ways of installing circuits without the use of RCDs and they are still 17th edition compliant.

 

[b33k34]

thanks - i was just wondering if there were any changes 'under the hood' that I couldn't see.

 

[PrenticeBoyofDerry]

thanks - i was just wondering if there were any changes 'under the hood' that I couldn't see.

Not really, other than the RCD stuff.
As mentioned in previous posts, it's a selling point by stating 17th edition CU.
They are normally dual RCD protected which is a logical step, but even single RCD protected boards are 17th edition compliant. I am not suggesting you use one, as you can pick up okay 17th ed CUs fully loaded, for as little as £60.

 

[b33k34]

I am not suggesting you use one, as you can pick up okay 17th ed CUs fully loaded, for as little as £60

Which, indeed, I did. Wylex as well. [/quote]

 

[NewOrder]

Would it technically be possible to use a Wylex standard 8 way in a new install and make it 17th edition complaint? I know it would be expensive having all those separate RCDs, and rather daft but it is a hypothetical question.

 

[Paul_C]

Would it technically be possible to use a Wylex standard 8 way in a new install and make it 17th edition complaint? I know it would be expensive having all those separate RCDs, and rather daft but it is a hypothetical question.

Certainly it would be possible. You could use two RCD's, each feeding a separate Wylex Standard board, which would result in the equivalent arrangement to a single unit with two integral RCD's and a split bus.

 

[westie101]

An all RCBO board would more than comply! (though not cheap)

 

[seasickstevie]

... expensive having all those separate RCDs, and rather daft but it is a hypothetical question.

Definitely not daft.

Considering the price difference, I wouldn't consider anything less than a high integrity board these days.