Amendment 2 coming out next year thoughts?

[Rockingit]

Apart from the fiasco that will become foundation earthing, my largest consideration with AFDD's is simply how the heck are we meant to test them. I can see it now that the likes of Megger and Fluke et al are rubbing their hands in glee knowing that soon they'll be selling thousands and thousands of new MFT's......

 

[Rockingit]

OK.... results of some brief research is that basically they can't be tested anyway, beyond the internal T button (am sure this must have been discussed in other threads on here in the past). What WILL be a pain for testing is that you can't do a 500V IR from source side due to the internal electronics so gone are the days of a global IR at the board, each leg needs removing.

 

[Dustydazzler]

Arc Fault Circuit Devices can;t be tested beyond the T button and if they won't hold in then bin it and buy a new one.

 

[UNG]

Apart from the fiasco that will become foundation earthing, my largest consideration with AFDD's is simply how the heck are we meant to test them. I can see it now that the likes of Megger and Fluke et al are rubbing their hands in glee knowing that soon they'll be selling thousands and thousands of new MFT's......

Had a conversation with a couple of guys on the Megger stand at an Elex a couple of years ago when the AFDD's started appearing and they were saying that it was unlikely that there would be a tester available to confirm the operation of AFDD's. The identification of nuisance tripping came into the conversation and the conclusion was you swap it out and if it stops the tripping then it was faulty if not you are looking for a fault on the circuit that may not be found with the test equipment we have and possibly the only way to cost effectively repair would be to rewire the whole circuit

 

[westward10]

DId I read on here not too long ago that in the US, it is not uncommon to fit AFDDs (or whatever they call them over there) on some circuits, but then remove them after sign-off of the work because of nuisance tripping? Or am I imagining this?

No I am pretty sure it was @Megawatt

 

[Gavin John Hyde]

Could you not test an afdd by getting two loose wires then using some vde pliers create pretty little arcs..??
In real terms a sort of tazer like device with the arc in an enclosure?

 

[UNG]

Could you not test an afdd by getting two loose wires then using some vde pliers create pretty little arcs..??
In real terms a sort of tazer like device with the arc in an enclosure?

Could you create the right arc signature to trip the AFDD though

 

[Dustydazzler]

Could you create the right arc signature to trip the AFDD though

This D.S vid on Affddds is probably the best explanation of how an Afffdddds work on the web

 

[Welchyboy1]

This D.S vid on Affddds is probably the best explanation of how an Afffdddds work on the web

Great video!

Dreading the thought of starting to install and fault find these when they become required, at least an RCD fault you have a means to test and narrow it down, seems its just a visual inspection is all we can really do in some cases and if no scorch marks are apparent just retighten connections and keep resetting the thing till its happy

Even IR testing will only really work on a parallel fault

Definatly sounds like a good idea with electric shower circuits though

Can see alot of sparkys ducking out of these types of call out in the future

 

[Dustydazzler]

Great video!

Dreading the thought of starting to install and fault find these when they become required, at least an RCD fault you have a means to test and narrow it down, seems its just a visual inspection is all we can really do in some cases and if no scorch marks are apparent just retighten connections and keep resetting the thing till its happy

Even IR testing will only really work on a parallel fault

Definatly sounds like a good idea with electric shower circuits though

Can see alot of sparkys ducking out of these types of call out in the future

Half day call-out , drop off every single point and check every single connection.

 

[pc1966]

My favorite proposed change along with the AFDD thing is earth of building foundations, who the hell is going to know once the concrete is poured, and how do you check it after for an EICR!

Oddly enough that is the one change that I think makes sense!

• AFDD - too expensive, little proof they actually are value for money in terms of saved lives versus lives lost due to board changes being refused on cost, etc.
• RCD mandatory - stupid for data centres and the like where you have high leakage stuff, safe environment, and want to be able to swap in an emergency without getting a spark in some time next week.
• Foundation earth for TN-C-S - should have been in the regs years ago when it started!

As for testing a foundation earth, my suggested approach is two bond wires to the buried steel in separate locations then to verify the bond soundness you do an end-end check on the two bond wires, like the RFC test.

 

[SparkySy]

@pc1966 I agree that it is a perfectly reasonable idea and that done correctly would be of benefit! Having been involved with agricultural installations for several years this is normal practice and if done as you say can be easily confirmed that it is still connected correctly. If you can find a trustworthy groundwork team! I have been on some jobs where it has been completely forgotten and has caused some major works to rectify.

 

[Lister1987]

OK.... results of some brief research is that basically they can't be tested anyway, beyond the internal T button (am sure this must have been discussed in other threads on here in the past). What WILL be a pain for testing is that you can't do a 500V IR from source side due to the internal electronics so gone are the days of a global IR at the board, each leg needs removing.

I dunno @dseselectric did a rather spiffing video on an AFDD tester ?

 

[telectrix]

Could you not test an afdd by getting two loose wires then using some vde pliers create pretty little arcs..??
In real terms a sort of tazer like device with the arc in an enclosure?

youse got shares in knipex/CK/bahco?

 

[telectrix]

my tuppence worth. those of us who are bona fide sparks will ignore the afdi crap and still do a decent safe job at a sensible cost, thus doing our best to keep the cowboys at bay.

 

[Megawatt]

No I am pretty sure it was @Megawatt

We have builders over here tell the electricians to install them and then remove them after their final inspection. I personally don’t do that.