Opinions please.

[Dave OCD]

I have an extension to wire this week which is a garage conversion comprising a study, shower room and small store area. The supply is TT and I'm intending on running a 16mm sub main from the existing mains position under the suspended floor through the hall in the house and installing a new small CU with RCBOs in the new store area. Due to the earthing arrangements I'll fit an S type 100ma RCD and 60a Switch-fuse [possibly 63a MCB] at the supply end, either seperate units linked by tails or integrated in one unit if I can source something suitable. Do you think these items should be Amendment 3 compliant as I don't think I've seen such a beast yet ? Any pointers to similar recently used kit would be welcome. :smilewinkgrin:

 

[Leesparkykent]

I have an extension to wire this week which is a garage conversion comprising a study, shower room and small store area. The supply is TT and I'm intending on running a 16mm sub main from the existing mains position under the suspended floor through the hall in the house and installing a new small CU with RCBOs in the new store area. Due to the earthing arrangements I'll fit an S type 100ma RCD and 60a Switch-fuse [possibly 63a MCB] at the supply end, either seperate units linked by tails or integrated in one unit if I can source something suitable. Do you think these items should be Amendment 3 compliant as I don't think I've seen such a beast yet ? Any pointers to similar recently used kit would be welcome. :smilewinkgrin:

If it has a suspended floor would it be just as easy to run the new circuits back to the existing CCU position? Split the tails and add in new board at this position or upgrade the existing board if the customers willing to pay. This way would be cheaper and Imo more convenient for the customer by not having a board in a remote position.

 

[Leesparkykent]

Wylex now make switch fuses for use in a domestic property.

 

[Dave OCD]

If it has a suspended floor would it be just as easy to run the new circuits back to the existing CCU position? Split the tails and add in new board at this position or upgrade the existing board if the customers willing to pay. This way would be cheaper and Imo more convenient for the customer by not having a board in a remote position.

I did think of that Lee but he wants the new bit seperate as it may be a self contained holiday let in the future.

 

[Dave OCD]

Wylex now make switch fuses for use in a domestic property.

Yeah nobody around here seems to have them yet . Do you know if they're available ?

 

[Leesparkykent]

https://www.edwardes.co.uk/en/categories/wylex-domestic-all-metal-switch-fuse-units

 

[Dave OCD]

Thanks Lee, not a bad price, I had afeeling it would be more than that ! Still leaves me with the S type RCD to fit and enclose appropriately though, and all this will sit next to an existing insulated CU. :banghead:

 

[Leesparkykent]

Also found these for a decent price as I found a lot of wholesalers are taking the mick for the wiska version. http://remora.net/catalogue/nylon-c...ail-Kits/GripLoc-Consumer-Unit-Tail-Kit-Nylon

 

[Dave OCD]

Also found these for a decent price as I found a lot of wholesalers are taking the mick for the wiska version. GripLoc® Consumer Unit Tail Kit - Nylon

I can see the linkwhen quoting your post Lee but not showing in the original post on my machine ?

 

[Dave OCD]

Also found these for a decent price as I found a lot of wholesalers are taking the mick for the wiska version. GripLoc® Consumer Unit Tail Kit - Nylon

I've been quoted £10+ EACH for the Wiska version !

 

[Deleted member 9648]

Hows that wylex unit Am3 compliant if the doors left open?

 

[Leesparkykent]

I can see the linkwhen quoting your post Lee but not showing in the original post on my machine ?

I forget to add the link to the post lol. I then edited and added it so might be that.

 

[Leesparkykent]

Hows that wylex unit Am3 compliant if the doors left open?

Is it an actually requirement that the door is hinged to shut itself? Just think if you had to install a 3phase board within a domestic property if this was the case.

 

[Leesparkykent]

I've been quoted £10+ EACH for the Wiska version !

That's what I mean, I've been quoted similar...most wholesalers seem to be trying to rip the arse out if it. These ones are just as good, do exactly the same job and for under £2...cant complain at that.

 

[Dave OCD]

Had to fit a couple of Wylex Amd 3 units a couple of weeks ago in an awkward spot at the back of a cupboard, the lids were a pain to fit with the drop down covers and the metal blanks fell out more than once.

 

[Leesparkykent]

For the rcd enclosure you might have to use a two way board and a couple of blanks. Cant seem to find anything compliant.

 

[Dave OCD]

That's what I mean, I've been quoted similar...most wholesalers seem to be trying to rip the arse out if it. These ones are just as good, do exactly the same job and for under £2...cant complain at that.

I actually tried a standard 32mm Wiska plastic gland asan experiment with 16mm tails/10mm earth and found the insert squashes/compresses enough to seal it all up pretty well. [It would certainly meet IP4X]

 

[Dave OCD]

For the rcd enclosure you might have to use a two way board and a couple of blanks. Cant seem to find anything compliant.

That's what I'm thinking Lee, tempting to use a small compliant board with the S type as the main switch and a 63a MCB for the sub main, but compared to a fuse it could cause discrimination issues I think. :smile5:

 

[Leesparkykent]

That's what I'm thinking Lee, tempting to use a small compliant board with the S type as the main switch and a 63a MCB for the sub main, but compared to a fuse it could cause discrimination issues I think. :smile5:

That's the problem as even a 6A mcb will offer none to very little discrimination with the 63A mcb...in an ideal world you would put the distribution circuit on a fuse.

 

[Dave OCD]

That's the problem as even a 6A mcb will offer none to very little discrimination with the 63A mcb...in an ideal world you would put the distribution circuit on a fuse.

Yeah it'll have to be a fuse, I'm glad I priced this one adequately !

 

[Flanders]

Cant you use a type d mcb

 

[Leesparkykent]

Cant you use a type d mcb

Wont make a difference where discrimination is concerned.

 

[Leesparkykent]

http://edmundson-electrical.voltilink.co.uk/articles/guide-discrimination this is a good read.

 

[Flanders]

Thanks for that lee think i been miss guided in the past was thinking about discrimination for overload not short circuit .

 

[Dave OCD]

Cant you use a type d mcb

It did occur to me ,might be ok on overcurrent 'tripping' on one of the final circuits but in the event of a l-n short it would most likely go at the same time ?

 

[Dave OCD]

Beaten to it again !:biggrin:

 

[Amp David]

What brand of RCBOs you using in the new CU.? Always found DP versions tricky to get

 

[Leesparkykent]

What brand of RCBOs you using in the new CU.? Always found DP versions tricky to get

SBS do single pole switched neutral RCBOs.

 

[Deleted member 9648]

Is it an actually requirement that the door is hinged to shut itself? Just think if you had to install a 3phase board within a domestic property if this was the case.

No,it's not a specific requirement....but for me that is not complying with the intention of the regulation which is a fire resistant enclosure over all 'combustible' components as far as is practical. That is why all Am 3 designed enclosures I've seen have a top hinged metal lid. I wouldn't fit that wylex unit. I take your point about the 3 phase board,but that would easily be overcome by fitting 3 separate single phase DB's if you took the view that a side hinged door was not compliant. I would take that view as the door left open would negate any fire resistance of exposed 'combustible' components.

 

[Leesparkykent]

The hinged lid is a good idea but I've already seen a board installed where the wall was out and the lid ever so slightly stayed open. Imo a catch or similar is better. Edit: What switch fuse would you install? As there doesn't appear to be many on the market atm that meet the requirements.