Amendment 2 and AFDD's | Page 6 | on ElectriciansForums

Discuss Amendment 2 and AFDD's in the UK Electrical Forum area at ElectriciansForums.net

Dave Appleby

-
Arms
Joined
Mar 19, 2018
Messages
163
Reaction score
207
Location
Scotland
Hi.

Been reading the but around 427.1.7.

Does anyone have any idea on retrospective application?

Is this going to apply to every board change or just adapted to new builds and then as a C3 recommendation for everything else?

Given prices it's going to be a massive cost change on a board swop. Plus, I know for certain I'm going to have space issues with anything over 30 years old here in Fife.

Thoughts?
 
I did read over the proposed amendment and AFDD are not being pushed for lights or high current loads like showers. Odd really, as most seriously burned out examples I have seen have been shower circuits, but maybe good old fashioned resistance and so no arcing to make one trip?

So it might be a case that really they only get used for sockets, in which case I foresee the return of a single/dual RFC per property!
 
Hager has a document claiming that they work on RFC's but acknowledge that only if the fault is on a spur or appliance connection
Helpful link. Confirming then what we suspected, that RFC fixed wiring is not protected against a series arc, except in the extremely unlikely scenario of 2 arcs taking place simultaneousely.
 
So it might be a case that really they only get used for sockets, in which case I foresee the return of a single/dual RFC per property!
You may well be right. But it could just as easily happen that the introduction of the AFDD ends up heaping more negative press on the RFC due to its inherant unsuitability for an AFDD protected circuit compared to the radial, which does not share these limitations
 
You may well be right. But it could just as easily happen that the introduction of the AFDD ends up heaping more negative press on the RFC due to its inherant unsuitability for an AFDD protected circuit compared to the radial, which does not share these limitations
No, you are not understanding the RFC limitation on AFDD.

They do detect arcs, it is just the "open ring" fault does not generate an arc (of any note) so it will not trip the AFDD. If you do get enough current flow and sufficient voltage to sustain an arc on some place in the RFC (so connection to socket or appliance) it will still detect it. So you might see that as a limitation on detecting faults, but then I really doubt that an open ring fault has ever caused a fire on its own as even the full 32A breaker limit on 2.5mm of one leg on a broken ring is overload, but more cable-life-killing and not fire starting temperatures.
 
No, you are not understanding the RFC limitation on AFDD.
I don't think I, m misunderstanding it. The "open ring" won't detect an arc. The "open radial" will detect an arc.
So you might see that as a limitation on detecting faults,
It depends on how the "powers that be" promote the AFDD. Over here the the protection afforded to the fixed wiring is emphasised as heavily as the protection afforded to the appliances connected to the fixed wiring. Like you I don't have any major concerns about arcing in a ring circuit as I have not experrienced(nor yet been presented with) credible evidence for series arcs in fixed wiring causing fires. But I, m simply making the point that the introduction Aof the AFDD is unlikely to enhance the ring circuits appeal (with exception of UK)
 
I don't think I, m misunderstanding it. The "open ring" won't detect an arc. The "open radial" will detect an arc.
Yes...but due to the open ring having practically no arcing.

It sounds very much like the arcing is a good thing here!!!
It depends on how the "powers that be" promote the AFDD. Over here the the protection afforded to the fixed wiring is emphasised as heavily as the protection afforded to the appliances connected to the fixed wiring.
Agreed, if it is for appliances then RFC or radial makes no difference.
Like you I don't have any major concerns about arcing in a ring circuit as I have not experienced (nor yet been presented with) credible evidence for series arcs in fixed wiring causing fires. But I, m simply making the point that the introduction of the AFDD is unlikely to enhance the ring circuits appeal (with exception of UK)
The RFC (in this context) only makes sense with fused plugs, and really only the UK and countries with a shared electrical history use the BS1363 plugs so the discussion is limited to them anyway.

The appeal of the RFC is around half the number of AFDD needed as half the number of circuits, and with a premium above RCBOs of ÂŁ100+ per circuit that starts to make it attractive!
 
I did read over the proposed amendment and AFDD are not being pushed for lights or high current loads like showers. Odd really, as most seriously burned out examples I have seen have been shower circuits, but maybe good old fashioned resistance and so no arcing to make one trip?

So it might be a case that really they only get used for sockets, in which case I foresee the return of a single/dual RFC per property!
Where is it stated they should not be used on shower cats?
 
I did read over the proposed amendment and AFDD are not being pushed for lights or high current loads like showers. Odd really, as most seriously burned out examples I have seen have been shower circuits, but maybe good old fashioned resistance and so no arcing to make one trip?

So it might be a case that really they only get used for sockets, in which case I foresee the return of a single/dual RFC per property!


Burned up connections are typically not the result of arcing, but rather series resistive heating which happen to be behind 95% of all electrical fires.
 
Perhaps we should install all power circuits with parallel conductors. For another amendment/edition, all accessories could include another live terminal for high integrity supplies.
 

Reply to Amendment 2 and AFDD's in the UK Electrical Forum area at ElectriciansForums.net

News and Offers from Sponsors

  • Article
Join us at electronica 2024 in Munich! Since 1964, electronica has been the premier event for technology enthusiasts and industry professionals...
    • Like
Replies
0
Views
293
  • Sticky
  • Article
Good to know thanks, one can never have enough places to source parts from!
Replies
4
Views
802
  • Article
OFFICIAL SPONSORS These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then...
Replies
0
Views
834

Similar threads

  • Question
Jumping on and off jobs can be tough going when you're less than confident as every time you go back it's like a new job. that you know little...
    • Like
2
Replies
15
Views
2K
nicebutdim
N

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top