T
Toneyz
Sorry I don't know how to post up a youtube link but have a look at the John Ward one part 2 on AFDD's worth a watch.
Saw it earlier. Makes you wonder if they are any good?
Its the downside to letting commercial interests get on the jpel/64 and influence regs. The companies that make them have seen £ signs galore with these.
Its the downside to letting commercial interests get on the jpel/64 and influence regs. The companies that make them have seen £ signs galore with these.
P
PEG
These devices are starting to look like that bomb detector,the dude had the military over with....i think he drew 6 figures,before they looked inside it...and locked him up
McCormick was his name,got ten years....maybe he's serving it at Eaton's R&D division?
McCormick was his name,got ten years....maybe he's serving it at Eaton's R&D division?
Last edited by a moderator:
B
Bobster
Without any way to test the functionality of an AFDD on site correctly (outside of a lab), they have been introduced far too early.
Considering the price of them not being cheap. How are you going to explain the only way you can check if one is faulty is replacing it.
(An actual solution described in the troubleshooting of one manufacturer.)
They've been around for a while in the US now and cause nothing but bother. Fridge compressor starting causes tiny arc in contacts (something it's designed to handle) ooops half the house is now without power. An there is no test you can do to prove anything is ok.
Considering the price of them not being cheap. How are you going to explain the only way you can check if one is faulty is replacing it.
(An actual solution described in the troubleshooting of one manufacturer.)
They've been around for a while in the US now and cause nothing but bother. Fridge compressor starting causes tiny arc in contacts (something it's designed to handle) ooops half the house is now without power. An there is no test you can do to prove anything is ok.
Shoei
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AFDDs are a response to an American problem, 30k housefires a year caused by high-current radials in wooden buildings, and what we would call substandard wiring - lots of wire nuts, for example.
A feature of RFCs is they don't arc if there's a single break, a safety factor that AFDD makers want us to abandon, just so the AFDD can detect an arc if a break happens. In other words, increase the chances of a dangerous fault just so an AFDD can detect it.
Sparks are supposed to recommend AFDDs and note if the customer declines. How is the customer meant to make that technical judgement?
A feature of RFCs is they don't arc if there's a single break, a safety factor that AFDD makers want us to abandon, just so the AFDD can detect an arc if a break happens. In other words, increase the chances of a dangerous fault just so an AFDD can detect it.
Sparks are supposed to recommend AFDDs and note if the customer declines. How is the customer meant to make that technical judgement?
Good point Mate, but with some of the prices of AFDDs being bandied about, I think the decision not to use them will be a financial choice.
Ha! That's a brilliant video - there's nothing in that bloody great big thing apart from a green LED. How big a CU are we supposed to need to get a few of them in? Half the places you find them installed in won't have enough room. Nice one IET, when are the £1K testers coming on sale, mind you they should be pretty simple things to test the innards of that pile of junk.
A pretty damming example of how these AFDDs aren't all they are made out to be, it was a low load, but how much will it take to start a fire?????? good video JW
this guy got an afdd to trip. not sure how realistic his experiment is though. the video from 12mins onwards shows the experiment, so skip the waffle.
Nice vid.
Are you sure he tested it correctly to standards IEC 62606 and 60898-1?
I showed this vid to one of the guys at work. We couldn't find the spec for the Eton on but we looked at a ABB one.
He was testing on a 40W load. That's 0.17A on a 16A device.
The ABB graph doesn't even go down that far. It just goes to 0.1 (which is 1.6A. 10th of 16A) and it is looking for an ark of 1 second at about 2.5A, so could be up to 10 seconds for 0.17A assuming the graph continues up.
http://search.abb.com/library/Downl...guageCode=en&DocumentPartId=PDF&Action=Launch
Are you sure he tested it correctly to standards IEC 62606 and 60898-1?
I showed this vid to one of the guys at work. We couldn't find the spec for the Eton on but we looked at a ABB one.
He was testing on a 40W load. That's 0.17A on a 16A device.
The ABB graph doesn't even go down that far. It just goes to 0.1 (which is 1.6A. 10th of 16A) and it is looking for an ark of 1 second at about 2.5A, so could be up to 10 seconds for 0.17A assuming the graph continues up.
http://search.abb.com/library/Downl...guageCode=en&DocumentPartId=PDF&Action=Launch
Yes but I think he was trying to say that the small spark he WAS creating might be enough to start a fire. Might.......obviously the more juice you have the more likely you are going to get a decent spark, but these days you often are not going to be using much, especially on lighting circuits. So is it worth it?
I understand where you are coming from mate, but it looks like the people who wrote the standards for these devices don't think that these small sparks are significant enough to cause a fire, as if they did then the AFDD's would be designed to detect them.
S
stevethesparks
This just reinforces my original thoughts....what a pile of carp.
It might have been an idea to have increased the loads whilst monitoring the temperature of the point of arc.
It's a good idea but ill thought out and too rushed thorough, as well as being far too expensive.
At least the design of an RCD does not require any electronics and works on basic science.
You can basically ignore the tests done on the vid as they are flawed.
It's disappointing really, as when you look at it, it looks like John Ward did not actually read the spec before doing the test. If he did then he knew his test would never trip the AFDD.
Not really mate. Read my post #15.
Thanks Spoon message to me read the entire post before asking a question, the answer is more than likely already there.
I won't be recommending AFDDs to anyone i work for . Stinks of corporate back handers .
I have devised a way of testing them though ...
It involves a kettle plugged into a socket and me at another socket arcing the live wires whilst doing a headstand on the 18th Edition
I have devised a way of testing them though ...
It involves a kettle plugged into a socket and me at another socket arcing the live wires whilst doing a headstand on the 18th Edition
Thanks Anthony for the very informative post....probably need Michael more on the case
Not really informative mate. The test was a farce.. Read post #15
N
Nigel
It is quite alarming how these false videos are just taken as gospel by people as if millions of pounds of research would be wrong but an anorake in a shed with crap equipment is correct.
It's easy to make people believe rubbish, when they don't like thinks in the first place. It falls into their beliefs.
I agree that the testing is not laboratory level, but would those arcs not be more akin to that which would be found in the real world?
Which is surely what matters rather than precise laboratory generated arcs from signal generators which exactly match the algorithms that the device is programmed with?
Spoon, you are correct with the current levels required.
My concern is that as Spoon suggests the minimum arc current is 2.5A, now we are being told that we should fit these in places where there is an increased risk of fire, and external influence BE2 is mentioned, an enhanced risk of fire due to the nature of processed and or stored materials.
Now we are already required to fit a 0.3A RCD in these situations.
Now 0.3 A to (humour me please) 3A, which is 2.5 rounded up. is a change of an order of magnitude.
If, the maximum fault energy to cause a fire is required to be limited by an RCD to 0.3^2 x t, then why is it allowed to be 2.5^2 x t for an AFDD?
Could this be because the technology was "invented" in the USA, and it is fundamentally flawed, considering the guy who "invented" it has stated that it doesn't work, it seems that the manufacturers have done a good selling job to the committees.
Also, it won't work on a ring circuit, but, we still have to fit them because "it is there to protect against appliance faults", that is a quote from one of those "in control" of the industry.
So we are now having to fit a device that costs the customer like £1 per circuit per year, on every circuit, and we are supposed to be reducing carbon emissions, and saving energy...
I'm not saying that JW's videos are perfect, but, there is a lot more research that needs to go into this to prove that these devices are fit for purpose surely?
Think about it, if the AFDD costs £1 per year, 10 circuits £10, now if these are coupled with an electronic RCBO, is that another £1 per year?
Remember not all RCD's are now made on the old torroid coil principle, many have microprocessors and current sensors with AtoD converters etc. so they need power to work, which is why they must be connected in a specific line/load configuration.
So is that £20 per year, per household, think about this, multiply that by basically every circuit in the country...
These are also, not as sensitive or well proven as RCD's either, so can we rely on them for protection?
Please note, I'm not looking for an argument, more for a well rounded debate.
Which is surely what matters rather than precise laboratory generated arcs from signal generators which exactly match the algorithms that the device is programmed with?
Spoon, you are correct with the current levels required.
My concern is that as Spoon suggests the minimum arc current is 2.5A, now we are being told that we should fit these in places where there is an increased risk of fire, and external influence BE2 is mentioned, an enhanced risk of fire due to the nature of processed and or stored materials.
Now we are already required to fit a 0.3A RCD in these situations.
Now 0.3 A to (humour me please) 3A, which is 2.5 rounded up. is a change of an order of magnitude.
If, the maximum fault energy to cause a fire is required to be limited by an RCD to 0.3^2 x t, then why is it allowed to be 2.5^2 x t for an AFDD?
Could this be because the technology was "invented" in the USA, and it is fundamentally flawed, considering the guy who "invented" it has stated that it doesn't work, it seems that the manufacturers have done a good selling job to the committees.
Also, it won't work on a ring circuit, but, we still have to fit them because "it is there to protect against appliance faults", that is a quote from one of those "in control" of the industry.
So we are now having to fit a device that costs the customer like £1 per circuit per year, on every circuit, and we are supposed to be reducing carbon emissions, and saving energy...
I'm not saying that JW's videos are perfect, but, there is a lot more research that needs to go into this to prove that these devices are fit for purpose surely?
Think about it, if the AFDD costs £1 per year, 10 circuits £10, now if these are coupled with an electronic RCBO, is that another £1 per year?
Remember not all RCD's are now made on the old torroid coil principle, many have microprocessors and current sensors with AtoD converters etc. so they need power to work, which is why they must be connected in a specific line/load configuration.
So is that £20 per year, per household, think about this, multiply that by basically every circuit in the country...
These are also, not as sensitive or well proven as RCD's either, so can we rely on them for protection?
Please note, I'm not looking for an argument, more for a well rounded debate.
N
Nigel
JW should have been honest in his video and said that the device is not made to trip at these levels. I suggest he actually did not know they were not supposed to trip at those levels and niether did 99% of us.
A good job by the manufacturers and a poor job by us for taking things as gospel.
Well done Spoon.
A good job by the manufacturers and a poor job by us for taking things as gospel.
Well done Spoon.
I can't take the credit for this @essex as it was a mate at work that pointed it out to me. I was initially a sheep, like most, who believed that the AFDD's should be detecting most arks.
As @netblindpaul has pointed out "If, the maximum fault energy to cause a fire is required to be limited by an RCD to 0.3^2 x t, then why is it allowed to be 2.5^2 x t for an AFDD?"
I presume it's down to cost. When you look at how the AFDD's detect arks then if they were to detect 30mA then there is going to be lots of nuisance tripping, unless the detection device is more fine tuned. This will increase the cost of these even more.
As @netblindpaul has pointed out "If, the maximum fault energy to cause a fire is required to be limited by an RCD to 0.3^2 x t, then why is it allowed to be 2.5^2 x t for an AFDD?"
I presume it's down to cost. When you look at how the AFDD's detect arks then if they were to detect 30mA then there is going to be lots of nuisance tripping, unless the detection device is more fine tuned. This will increase the cost of these even more.
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