AFCI Breakers

[Tony S]

Thanks, that is awesome! Beautiful work btw


May I ask, what purpose do the white wires serve coming from the RCBOs and then connecting to the earthing terminal?

They are for earth reference, just in case there?s a problem with the neutral.

All bases covered!

 

[mbrooke]

They are for earth reference, just in case there?s a problem with the neutral.

All bases covered!

They will trip on an open neutral or they will allows the RCBO to trip even with the neutral open? Just wondering how it works.

 

[Tony S]

I disagree, UK RCDs are even simpler than our GFCIs, a detailed report is better than a test button alone. Kind of like testing a diesel back up generator 30 minutes a month vs starting it up then 95% load banking it for 2 hours a month.


I however will let Tony have the honor of explaining it.

We have a test method that I will post up later. (I?m off to the pub soon)

Before a new installation will be energised by the supply company an installation certificate is required. This will have all IR and Z readings for every circuit.

Because I live in a flat I?m obliged to have three yearly reports done.
EICR = Electrical Installation Condition Report.

There is also a minor works certificate which covers things like installing a new socket outlet. No matter how old the installation is, the earthing/bonding has to be correct for the work to proceed.

 

[mbrooke]

We have a test method that I will post up later. (I?m off to the pub soon)

Before a new installation will be energised by the supply company an installation certificate is required. This will have all IR and Z readings for every circuit.

Because I live in a flat I?m obliged to have three yearly reports done.
EICR = Electrical Installation Condition Report.

There is also a minor works certificate which covers things like installing a new socket outlet. No matter how old the installation is, the earthing/bonding has to be correct for the work to proceed.

Definitely stricter than the US. Any info on testing will be worth it, as its rare in the US.


I cant help to think that if the US tested new circuits perhaps there would not be a need for AFCIs to begin with? IR testing is good at catching insulation damage ahead of time.

 

[romex jockey]

The AFCI manufacturers sold their concept on the NRTL's just like they did the NEC, and I believe most improvements they have made to their products has been by their own findings not suggestions from any NRTL. So in essence the manufacturers made the device, set the standards, set the testing requirements (or at least had a major role in setting testing requirements for listing) basically they have total control over design, approval, and introduction into codes, they put enough money and time into gaining this control that nobody can afford to challenge anything they have done - that is why you have all these people that have ideas of what is wrong with them and even show demonstrations - but they don't have the financial backing to take it to the level to actually challenge the AFCI manufacturers. Not saying either side of that is totally correct, but maybe if they could both eat at the same table - maybe we could get a useful and reliable product for the purpose sooner instead of later.

One would think the trade would be privy to the details Kwired

Otherwise, the whole issue just becomes our trades global warming debate

~RJ~

 

[romex jockey]

EICR = Electrical Installation Condition Report.

While i applaude the focus on safety, i'd image instituting such requirements here a rather chaotic experience

Conversely, i'm off to an apartment complex monday that hasn't seen an inspection of any sort for over 30 years , the flip side of it all.....

~RJ~

 

[MasterTheNEC]

But in all honesty it has NEVER been established that arc faults are responsible for dwelling fires or even to what degree. Yes testing has shown under the right conditions a lamp cord or damaged cable will arc, but none of that has determined to what degree it takes place in the real world.

I know you have everyone's best interest in mind, and I am sure the CPSC, NEMA, ect and the CMPs do, but they are not infallible or immune to human error. People make mistakes, everyone does. At one point the best minds thought the earth was flat, and latter that everything in physics had already been discovered with the only thing needing more precise measurement; of course astronomy, relativity and quantum mechanics proved wrong. Its possible in an effort to target a very real problem (like electrical fires) that something was overlooked.

Agreed.......so why not those who have that GREATER knowledge continue to press for change if they believe it is so. Let's face it...the Home Builders Association has the deepest pockets of all of the anti-AFCI proponents and pay for many independent studies and they serve on CMP 2......yet again they FIGHT the AFCI at every chance so why would they have not proposed data on contrary to what the manufacturers claim. Let's not say it is because they are in the pockets of the manufacturers because I know that not be true having worked with both......so.....so much theory....

So with all the passion to debunk AFCI's.....why would someone not put together the data to prove them wrong and take all the glory for saving mankind from needless wasted spending......WHY?

 

[don_resqcapt19]

...
However, we don't know what the test current really is or the exact opening time. An microprocessor tester is far more accurate, and the ramping current effect is more thorough over a fixed, unknown resistor.

If it is within the standard, do we really care about the exact numbers? I expect that the GFCI standard specifies the resistance of the resistor or the amount of current that it should flow at 120 volts. I don't have a copy of the standard to verify that. Most GFCIs trip much quicker than what the standard permits. I think if there was any delay, even a delay much less than the 3.7 seconds that the standard permits, I would replace the device.

 

[kwired]

One would think the trade would be privy to the details Kwired

Otherwise, the whole issue just becomes our trades global warming debate

~RJ~

That is the problem, they are not as simple as the GFCI is - and even GFCI is not understood by a lot of those in the trade.

You have a large number of people in the trade that are just installers, and know how to connect things but when it comes to how something works and the need to troubleshoot it when it doesn't work - there really aren't that many in the trade compared to number of installers only.

 

[Tony S]

If there were laughing that would only because they do not understand the test button is enough with the our GFCIs.

Your GFCI is identical to a 3 pole RCD baring the leakage current rating.

Both are subject to wear over time. If it has been installed for years and given perfect service wear takes place. Like me they get old, cantankerous and unreliable.

Have you ever stripped a GFCI? If you do you will see the bits that wear and they are very delicate and can be very temperamental.

Regarding the test button:
I?ve had the resistor burn out or even more fun, short circuit. The damn thing exploded.

I?m sorry, I can?t understand how pressing a test button constitutes a ?test?, far too many possibilities for variance.

A MFT (Multi Function Test meter) does the ramp test automatically. It will give trip threshold and response time in mA and mS. OK they are expensive and need annual calibration for insurance purposes.

Can you tell me the precise values the test button gives? If there was to be an insurance claim can you say you have tested the functionality of the device?

 

[Tony S]

This will take a few posts.
This is an editable form for an EICR (Electrical Installation Condition Report). I was going to post the original PDF but my moderators head stopped me.
OK it would be of no use to a US electrician but a UK electrician could download it. We don?t charge for these but you have to be a registered member of our forum to download the full PDF.
I?m afraid there?s nine .JPG?s but it will give an idea of the testing procedure and the legal implications, many insurance companies now insist on them. If you were to buy a house you will not get a mortgage without the report.

 

[Tony S]

 

[Tony S]

The UK is now moving to a new standard layout for domestic distribution to bring us in line with the rest of the world.

 

[mbrooke]

Awesome! I will probably use that from now on.


Just wondering, whats the difference between a 2 phase 3 wire supply and a 1 phase 3 wire supply?

 

[mbrooke]

The UK is now moving to a new standard layout for domestic distribution to bring us in line with the rest of the world.

:jawdrop:what country is that from?

 

[GoldDigger]

Awesome! I will probably use that from now on.


Just wondering, whats the difference between a 2 phase 3 wire supply and a 1 phase 3 wire supply?

Well, we can assume that 1 phase 3 wire is standard US 120/240 (or multiples of voltage) with L1-N-L2. Unless you also count the EGC I do not see any other way of meeting this description.
Now there is the slight possibility that 2 phase really refers to 90 degree phase shift, in which case you would have L1(0), L2(90), and N only N would be the grounded conductor rather than a true neutral.
Most likely would be 2 lines from a three phase system for "2 phase", which would be a subset of 208Y/120 in which only two of the three line conductors is present.
That is, you only get two different phases, (not counting 180 degree shift) and what would be a neutral in the full three phase set.

There is the off chance that somebody is calling 120/240 three wire "two phase", but that is discouraged. Even "split phase" is not particularly popular among electricians although non-E handydmen may use and recognize it when they see it.

 

[GoldDigger]

images....

And you have to pay to have this done three times per year? Sounds like guaranteed employment for inspectors.

 

[mbrooke]

Your GFCI is identical to a 3 pole RCD baring the leakage current rating.

Both are subject to wear over time. If it has been installed for years and given perfect service wear takes place. Like me they get old, cantankerous and unreliable.

Have you ever stripped a GFCI? If you do you will see the bits that wear and they are very delicate and can be very temperamental.

Regarding the test button:
I?ve had the resistor burn out or even more fun, short circuit. The damn thing exploded.

I?m sorry, I can?t understand how pressing a test button constitutes a ?test?, far too many possibilities for variance.

A MFT (Multi Function Test meter) does the ramp test automatically. It will give trip threshold and response time in mA and mS. OK they are expensive and need annual calibration for insurance purposes.

Can you tell me the precise values the test button gives? If there was to be an insurance claim can you say you have tested the functionality of the device?

The sad part is US GFCI are full of electronics, where UK RCDs are just a toroid coil and a solenoid?



Here is a US GFCI socket:


http://images.machinedesign.com/images/archive/scanning3jpg_00000037423.jpg

http://upload.wikimedia.org/wikiped...eak.jpg/300px-ResidualCurrentCircuitBreak.jpg

http://www.altoonalights.com/images/gfci/sm_inner_board.jpg

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elepic/gfi2.gif


Single pole 120 volt GFCI breaker (RCBO):

 

[don_resqcapt19]

This will take a few posts.
This is an editable form for an EICR (Electrical Installation Condition Report). I was going to post the original PDF but my moderators head stopped me.
OK it would be of no use to a US electrician but a UK electrician could download it. We don?t charge for these but you have to be a registered member of our forum to download the full PDF.
I?m afraid there?s nine .JPG?s but it will give an idea of the testing procedure and the legal implications, many insurance companies now insist on them. If you were to buy a house you will not get a mortgage without the report.
...

We don't need all of that...we just turn the power on and if there is no smoke we are good to go.

 

[iwire]

Your GFCI is identical to a 3 pole RCD baring the leakage current rating.

OK, why is it that previously in this thread I was told how much simpler an RCD was than a GFCI?

Both are subject to wear over time. If it has been installed for years and given perfect service wear takes place. Like me they get old, cantankerous and unreliable.

What 'wear' the parts are stationary other than a trip. If anything they might stick due to non-use but that is a problem every molded case circuit breaker has and we don't test them either. They are far to inexpensive to bother doing load testing of them. If they are suspect they are simply tossed out.

Have you ever stripped a GFCI? If you do you will see the bits that wear and they are very delicate and can be very temperamental.

The mechanical parts are the same as our standard thermo-magnetic trip breakers. There is no wear unless they happen to be tripping all the time and my experience tells me that wear makes them subject to early triping not late.

Regarding the test button:
I?ve had the resistor burn out or even more fun,

If the resister burns out the test button would not trip it so it would not pass the test. In other words .... no danger.

short circuit. The damn thing exploded.

Call me very doubtful.

I?m sorry, I can?t understand how pressing a test button constitutes a ?test?, far too many possibilities for variance.

I am sorry you cant understand it but that does not change the fact it is enough.

A MFT (Multi Function Test meter) does the ramp test automatically. It will give trip threshold and response time in mA and mS.

No need for that information, it only makes pretty reports.

One the breaker leaves the factory the trip time and trip level is not going to drift unless the mechanical parts seize up ....... and they it wont test with the button.

Can you tell me the precise values the test button gives?

No, and no one in the field needs to know that.

It either trips or it doesn't.

If there was to be an insurance claim can you say you have tested the functionality of the device?

Yes.