MCB, RCD & AFDD all in one

[Zdb]

These things are blooming huge!

Oh and £170

 

[Spoon]

'premises with sleeping accommodation' is a bit ambiguous, though. I'm assuming they mean hotels?

It is very ambiguous. The Oxford Dictionary says 'Accommodation' is "A room, group of rooms, or building in which someone may live or stay. ‘they were living in temporary accommodation’ "

Doesn't that put every house down as having "sleeping accommodation" ?

 

[johnduffell]

But if a fuse blows or an MCB trips you have test equipment to diagnose the fault quickly and reliably every time.

Yes, you can just look at the switch or at the melted fuse. But the same applies to the afdd. I thought people meant testing the device itself for correct operation, which you can only do with rcds.

With rcds you can test the rcd itself, and you can ir test the circuit.

With fuses and mcbs you can only test the circuit.
With afdds not sure! Maybe neither?

 

[Wilko]

It is very ambiguous. The Oxford Dictionary says 'Accommodation' is "A room, group of rooms, or building in which someone may live or stay. ‘they were living in temporary accommodation’ "

Doesn't that put every house down as having "sleeping accommodation" ?

Yep.
Fortunately 421.1.7 has two softeners for now. It says "If used..." and then gives "Examples of where such devices can be used...". This will change to "shall be used" at some point I guess.

 

[Bobster]

With fuses and mcbs you can only test the circuit.
With afdds not sure! Maybe neither?

Neither unless you're in a lab.

You maybe able to pick up a fault on the circuit with an IR but doubtful, as a L>N short should trip the MCB.

 

[Spoon]

Yep.
Fortunately 421.1.7 has two softeners for now. It says "If used..." and then gives "Examples of where such devices can be used...". This will change to "shall be used" at some point I guess.

But, pinching this from the earlier post, it also has:
421.1.7 arc fault detection devices conforming to BS EN 62606 are recommended as a means of providing additional protection against fire caused by arc faults in AC final circuits.

If there is a fire and it goes to court and the court says "BS6761 recommend that you use Arc Fault Detection Devices. Why didn't you fit them?" Where would you stand from a legal point of view?

 

[SparkyChick]

If there is a fire and it goes to court and the court says "BS7671 recommend that you use Arc Fault Detection Devices. Why didn't you fit them?" Where would you stand from a legal point of view?

I think if you could demonstrate you'd suggested it to the customer and that they'd nearly choked on their tea when told the price, you'd be fairly safe as you would have done your part.

Sure it could be argued that by continuing without insisting you've been negligent but at the end of the day it is only a recommendation at the moment and you recommended it... the customer chose not to take up the recommendation.

But it is yet another thing that Dangerous Dave won't give a t055 about meaning he'll be even cheaper than the rest of us. It's like the earth rod for TN earthing systems... if that becomes mandatory (I haven't got the big sky blue book yet) and is required to be applied retrospectively to existing installations (ala earthing and bonding up to snuff), customers will think you're just trying to fleece them.

This is part of the problem with the regs... they don't make it publicly known what homes should have and what people should expect, so the cowboys can get away without providing it. If they made more of an effort to educate householders it may help.

 

[Wilko]

Yes you are right @Spoon - it is recommended to have AFDD !
Normally (ha, what would I know) if the Customer won't agree to buy a product and it's not mandatory to have it, then I think we are ok. But we'd have to have that discussion and sign off (!!!).
Edit - what @SparkyChick said

 

[Spoon]

I think if you could demonstrate you'd suggested it to the customer and that they'd nearly choked on their tea when told the price, you'd be fairly safe as you would have done your part.

Good point @SparkyChick .
So you would have to do two quotes. One with AFDD's, explaining what they are and why you recommend them and a quote without. Then the responsibility is shifted to the customer.

 

[SparkyChick]

Good point @SparkyChick .
So you would have to do two quotes. One with AFDD's, explaining what they are and why you recommend them and a quote without. Then the responsibility is shifted to the customer.

I would do it as an option with a recommendation that the change can increase the safety of the installation.

 

[Deleted member 105166]

Having designed our four storey timber framed barn conversion to the 18th ed., including 18 AFDD circuits, 11 1P+N RCBO circuits & SPDs, today I received an email from Eaton's Regional Account Manager, stating;
"At the current time we do not have a distribution board solution for the AFDD. That means the AFDD would have to be mounted in a separate enclosure to a distribution board on a din rail with MCBs in the Distribution board feeding the AFDD units.
Let me know if this is a solution you would like me to look at."

So, despite all the marketing, the Eaton video, the reality is the only way to implement is a botch! So much for an "all in one device". I have replied this evening, asking how the product has ever been released, if it is not a type tested coordinated assembly, i.e. tested within an Eaton/MEM board.