AFDDs and SPDs has anyone read up on these things yet?

[Pete999]

I only ask because there is some useful bits printed in the New OSG which may be useful, if anyone has seen these information snippets it would be nice to see your thoughts, only if you can be bothered that is.

 

[Midwest]

Haven't got the new OSG, can you precis what it says?

 

[Pete999]

Haven't got the new OSG, can you precis what it says?

I will do abit later Mate when the meds wear off.

 

[Andy-1960]

Recently attended a NICEIC 'Tech Talk' and this was one of the subjects.

AFDD's at present are not compulsory but my thoughts are you may have some difficult questions to answer as to why you did not fit them if there was a fire. I think all we can do is advise the customer they are available and what the supposed benefits are and then let them make the decision as to whether or not they are required. One thing to not is they only appear to be available in single pole form up to 63A, so any 2 phase or 3 phase installs over 63A is free to arc and burn!

SPD's are a different matter and I need to get my head fully around this one, I spoke to a guy who is going to come and see me and explain fully what is required. The brief resume was that if a circuit goes thru a zone change (inside to outside for example) you must fit an SPD. But there are different types and zones which is what I need to fully understand.
SPD's are compulsory, so this is something we are all going to have to understand and design into our installations.

 

[Nigel]

AFFDs are only required in certain installations. You everyday domestic dwelling is almost certainly not required to need them.

SPDs have been in the Regs for some time and is based on a risk assessment on whether what is connected to the electrical installation need protecting. Again most domestic installations will not need an SPD.

 

[Nigel]

Recently attended a NICEIC 'Tech Talk' and this was one of the subjects.

AFDD's at present are not compulsory but my thoughts are you may have some difficult questions to answer as to why you did not fit them if there was a fire. I think all we can do is advise the customer they are available and what the supposed benefits are and then let them make the decision as to whether or not they are required. One thing to not is they only appear to be available in single pole form up to 63A, so any 2 phase or 3 phase installs over 63A is free to arc and burn!

SPD's are a different matter and I need to get my head fully around this one, I spoke to a guy who is going to come and see me and explain fully what is required. The brief resume was that if a circuit goes thru a zone change (inside to outside for example) you must fit an SPD. But there are different types and zones which is what I need to fully understand.
SPD's are compulsory, so this is something we are all going to have to understand and design into our installations.

You have three Types.

Type 1 - is installed as a catch all SPD at the beginning of the installation. (Main head area)

Type 2 - is installed at DBs.

Type 3 - is installed at specific items of equipment. (Servers etc).

 

[dmxtothemax]

AFCI is what the Yanks call them Arc Fault Circuit Interuptor.
They are manditory in a lot of places now,
How ever just like RCD's they still don't have all the bugs out
so nuisance tripping and just plain old incompatibilities with some loads is a real problem.

 

[Andy-1960]

AFFDs are only required in certain installations. You everyday domestic dwelling is almost certainly not required to need them.

SPDs have been in the Regs for some time and is based on a risk assessment on whether what is connected to the electrical installation need protecting. Again most domestic installations will not need an SPD.

AFDD’s are primarily aimed at the domestic market as this is where most people tend to sleep and that is what they are aiming these things at, so I think you will find most domestic installs will require one unless it is declined by the client.

SPD’s from what I am being told will be mandatory on all installations including domestic.. why would they be excluded?

 

[Pete999]

I will do abit later Mate when the meds wear off.

Like Andy-1960 says it's all a bit "got to get my head around all this stuff"
But what follows is only a precis on what the OSG and 7671 says, I don't have 7671 so cant really elaborate but here goes.
AFDDs
The OSG says that it is a recommendation to fit these devices as additional protection against fire in AC final circuits. Regulation 537.6
a) One single device, compromising an AFD unit in series with a suitable short circuit device, that complies with one or more of the following standards, BS EN 60898-1 61009-1 and or 60269 series.
b) One single device incorporating an AFD with an integrated protective device, BS EN 60898-1 61008-1 61009-1 or 62423.
c) An AFD add on module assembled on site. AFDDs shall be installed at the origin of the circuit to be protected.

SPD
Three types
Type 1 if there is a risk of direct lightning strikes
Type 2 For use at distribution boards
Type 3 For use near the terminal equipment
Where SPDs may not be required,
regulation 443.1 table 443.2
A single dwelling where the total value of the installation does not justify such protection.
Where SPDs are require regulation 443.4,
Where there is a danger of injury, loss of life such as Hospitals care homes and the likes.
Interruptions to public services heritage sites
Banks, hotels, supermarkets etc
Offices, Schools, Unis, Tower blocks

See GN 1 for further info

Hope this is OK it's only an overview

 

[Pete999]

AFDD’s are primarily aimed at the domestic market as this is where most people tend to sleep and that is what they are aiming these things at, so I think you will find most domestic installs will require one unless it is declined by the client.

SPD’s from what I am being told will be mandatory on all installations including domestic.. why would they be excluded?

Only recommended apparently regulation 537.6

 

[Andy-1960]

Only recommended apparently regulation 537.6

Thanks Pete, this is very interesting and not what they said at the ‘Tech Talk’ ... bit more research required I reckon.

 

[Pete999]

Thanks Pete, this is very interesting and not what they said at the ‘Tech Talk’ ... bit more research required I reckon.

Yes, Just as I expected Andy, it could have been a better idea if I had the actual regs book, but as I'm not practicing anymore it seemed a bit of a tall ask to buy both books, and the GNs to follow on with, I'm sure things will become clearer as time goes by.

 

[Strima]

And as usual we have to justify the cost to the customer who undoubtedly will say no.

 

[Midwest]

Manufacturers better get a lick on, if they are going to 'recommended' to be install in the domestic market by Jan next year.

 

[Pete999]

Manufacturers better get a lick on, if they are going to 'recommended' to be install in the domestic market by Jan next year.

I guess before the use of SPDDs are specified then the their use may not be required reg 443.1 table 443.2 should be looked at, AFDDS are only recommended regulation 537.6