My last 'non Amd 3' CU Install.

[Dave OCD]

Put this in today, I hope it doesn't burst into flames.:tongue3: Didn't have the time to faff about and get the cabling 'perfect' as I had so much to do today but I think it's ok. With the BG boards I generally 're number' the earth bar as to me it's illogical having the CPCs running in the opposite order of the neutrals,I'll miss the insulated CUs. Sorry about the
poor photo.

 

[Guest77]

Well believe it or not its not there are people who out there who dont adhere to such high standards, theyll whack a 3/8 twig in on top of a mountain and leave with there big cheque, have seen in numerous occasions out in rural areas!

You sheep shaggers will say anything to impress us English. Their :devilish:

 

[Dave OCD]

well i was always taught and still belive all tt system should have upfront rcd at origin for fault protection, if you are relying on the 30mA rcd in these mass produced dbs then althought ok to cover your own arse at install what happens in the future when these low end rcd's break down and the originalsinstallers poor tt 3/8 rod degrades leaving unacceptavle Ra to operate overload device within disconection times, the install is then in a very unsafe state for the building and user! Why has the op not stated if this is a TT and could shed more light on the install in question

Yes it is TT but what is the point of installing an 'up front' S type 100ma RCD when all it's effectively protecting is a very short run of surface meter tails from the main switch ? What alternative is there to mass produced DBs - do you manufacture your own ? Your other remarks about 'low end' RCDs and poor 3/8 earth rods are ridiculous too and maybe when in a hole you should stop digging ? The board was a Senate 'own brand' but manufactured by Wylex and I got a Ze of 36 ohms there,not bad at all for a TT. ALL installations will degrade over time and that's why a recommended interval for the next inspection is displayed prominently on the board itself and within the installation certificate. Now can you please explain why your initial post on this thread was so damning and actually downright insulting and post a picture of one of your perfect jobs so that we can all learn from it ?

 

[Dave OCD]

Do ya think Dave OCD is visiting relatives today, or just board with the whole thing now?

Spot on ! But home now and have put a little reply on for the bloke who thinks my work is rubbish. :wink5:

 

[shanky887614]

Spot on ! But home now and have put a little reply on for the bloke who thinks my work is rubbish. :wink5:

it is that time of year after all

 

[Deleted member 9648]

Yes it is TT but what is the point of installing an 'up front' S type 100ma RCD when all it's effectively protecting is a very short run of surface meter tails from the main switch ? What alternative is there to mass produced DBs - do you manufacture your own ? Your other remarks about 'low end' RCDs and poor 3/8 earth rods are ridiculous too and maybe when in a hole you should stop digging ? The board was a Senate 'own brand' but manufactured by Wylex and I got a Ze of 36 ohms there,not bad at all for a TT. ALL installations will degrade over time and that's why a recommended interval for the next inspection is displayed prominently on the board itself and within the installation certificate. Now can you please explain why your initial post on this thread was so damning and actually downright insulting and post a picture of one of your perfect jobs so that we can all learn from it ?

The point of an up front S type is back up should the 30ma RCD protection fail, RCD's apparently being of questionable quality these days and without a functioning RCD a typical TT will have zilch earth fault protection. There is good reason to include an S type then, but it is not a requirement, and the point could have been much better made by bigspark.
Personally I have not carried out a TT for a while,and most that I do are temporary installs regularly tested and inspected. For those I am content to apply regulations only as I don't find 30ma RCD's nearly as unreliable as others suggest. If I was carrying out a permanent TT install which would be unlikely to be re-tested for years,if at all, I would definitely include an S type up front.

 

[bigspark17]

The point of an up front S type is back up should the 30ma RCD protection fail, RCD's apparently being of questionable quality these days and without a functioning RCD a typical TT will have zilch earth fault protection. There is good reason to include an S type then, but it is not a requirement, and the point could have been much better made by bigspark.
Personally I have not carried out a TT for a while,and most that I do are temporary installs regularly tested and inspected. For those I am content to apply regulations only as I don't find 30ma RCD's nearly as unreliable as others suggest. If I was carrying out a permanent TT install which would be unlikely to be re-tested for years,if at all, I would definitely include an S type up front.

I agree and you have worded it far better than myself, must be all the sheep shagging as others have said haha. Maybe as i live in a rural area i come across more than my share of these TT installs than big city sparks. I feel instead of just about complying some installa need you to look at some of the dangers if things do fail and we can minimize that danger, afterall thats what the customer is trusting and paying us to do.

 

[Midwest]

I agree and you have worded it far better than myself, must be all the sheep shagging as others have said haha. Maybe as i live in a rural area i come across more than my share of these TT installs than big city sparks. I feel instead of just about complying some installa need you to look at some of the dangers if things do fail and we can minimize that danger, afterall thats what the customer is trusting and paying us to do.

So exactly what S type would you fit in Dave OCD's install?

 

[bigspark17]

100mA type S in its own enclosure after the meter/isolator

 

[telectrix]

100mA type S in its own enclosure after the meter/isolator

would that be a non-combustible (ferrous metal) enclosure, or would you enclose it in a fire-proof steel safe? :Angel_anim:

 

[Midwest]

100mA type S in its own enclosure after the meter/isolator

I'm just wondering what you would achieve in that case. I'm led to believe, that at currents above 20ma, electric shocks can cause breathing difficulties, and above 30ma can be fatal. A 100ma RCD more will provide protection against fire risks, but will not provide full personal protection. I'm willing to be corrected there. Electrical Safety First state that '97% of RCD's are reliable'.

So in Dave OCD install, what would installing an 100ma s type protect against?

I was under the impression, that installing a 100ma s type rcd, was to prevent against a metal clad CU becoming live, where the tails had shorted against the metal of the CU, not to provide protection against electric shock? Again only too willing to be corrected.

 

[telectrix]

the 100mA S type is to provide fault protection where the Ze is too high (as with a TT installation) to cause operation of OCPD within specified times. it is not there to protect against direct contact with live parts. this id down to the 30mA devices installed for the finals.

 

[Simonslimline]

The S type would be providing fault protection and no additional protection. I suppose the 30ma will also be providing fault protection, but also additional protection.

 

[Deleted member 9648]

What tel said.
An S type simply provides backup earth fault protection and would prevent a dangerous voltage appearing on conductive parts should a fault occur on a high Ze install with a sticky single RCD.

Regarding where to install said 100ma S type, for me it would be as a main switch in the Am3 metal cased DB.
In all my time as an electrician I have never known tails short onto a metal cased DB,far too much is made of the dangers IMO. In the case of a TT it is a simple matter to bush and secure those tails to remove any possibility whatsoever of a fault to the metal case. Think of the number of lights and appliances which are now class 11 and yet virtually all metal construction.
Having the main switch in the DB removes the complications of having to have an Am3 compliant enclosure for that as well as the DB.

 

[Englishman]

I notice that very few people share their board upgrades from properties that haven't been treated to a rewire beforehand. They're not always quite so easy to make them look good.

 

[Leesparkykent]

I notice that very few people share their board upgrades from properties that haven't been treated to a rewire beforehand. They're not always quite so easy to make them look good.

Board upgrades don't look as good unless the conductors or long enough. IMO when doing upgrades id rather have the board look a little untidy than add an unnecessary connection/point of failure just to dress the cables that little bit more neater.