Need To Fit An Rcd To An Old Rewireable Wylex

[shiner]

I been asked to extended a ring main in a kitchen by 2 sockets. Because it is a kitchen and the cables are going to have to go horizontal. I need to fit a separate rcd.  

What size cable do I bring from the c/unit. I think it's 6mm from the original fuse. 

 

[Sharpend]

6mm from the original fuse for sockets, is this a lolly pop circuit?

 

[m4tty]

Use SWA

 

[Sharpend]

Matty, he wants to know what SIZE,not what TYPE!

 

[Sharpend]

Now that's an answer!

 

[SLIPSHOD & SLAPDASH]

If its a 4mm ring then you would bring out at least an 8mm wouldn't you 

 

[ProDave]

Don't forget to advise the customer of the options for a proper CU upgrade.

Carefully cost FULLY the cost of fitting a separate RCD in an enclosure, and compare that with the cost of a new CU.

And point out you would have to do it again and bodge fit another separate RCD if you later modify another circuit.

It might make a new CU look more attractive.

 

[Bruspark]

I think we've failed to determine if the one legged "Ring" is actually a radial or a lollipop, failed to determine what extra load is planned or if it's already overloaded, failed to wonder if extending another circuit might be easier and failed to wonder how the end result will be tested or when the entire installation was last tested...

Oh ok. I'll get myself some more wine and shut up ...

 

[SPECIAL LOCATION]

I been asked to extended a ring main in a kitchen by 2 sockets. Because it is a kitchen and the cables are going to have to go horizontal. I need to fit a separate rcd.  

What size cable do I bring from the c/unit. I think it's 6mm from the original fuse. 

Irrespective of the type of circuit...

or type of consumer unit....

or if RCD's are involved....

Standard circuit design principals will still apply!

The load of the circuit will govern the required protective device rating....

the protective device rating and any derating factors will govern the minimum cable size permissible.

Simples! 

These basic calculations should answer your question...

As you haven't included this information it is a bit difficult for an accurate answer to be given.

If you are unable to calculate this yourself it may be best to seek assistance of a competent electrician who could give you a bit of on site guidance and practical advice...

Kitchens and utilities are typically the highest power usage areas of the average domestic property.

So proper design is still needed for all additions and alterations..

Guinness

 

[shiner]

It is a ring circuit downstairs. It's an elderly lady. 

In her kitchen she just has 2 sockets outlets. One is in the middle of the wall. All she wants is 2 other sockets either side about 300mm apart. The rcd can be fitted right next to the c/unit.  

 

[shiner]

I also ment 6mm to the rcd from the original fuse then the 2.5mm ring from the rcd

 

[binky]

assuming 30A fuse, 4mm would be fine, but as you have 6mm to hand, that will be more than adequate as it is capable of carrying more like 45A - check your big green book!

 

[shiner]

It is a 30a fuse. Thanks 

 

[M107]

I usually go with

1. Check the MEB's
2. Check circuit is good for extending (nothing like ploking on a 30mA rcd & you have IR issues, just because it's T/E at the cu doesnt mean thats whats under the floors)
3. Remove circuit legs from ocpd
4. 6mm T/E from circuit ocpd in to.
5. A small enclosure with >32A 30mA rcd (or one of SBS's rcbo's)
6. Connect circuit legs into rcd
7. Test 
8. cert
9. get payment
10. Foxtrot Oscar

Or

Use a method that negates the use of an rcd at the cu

 

[Bruspark]

M107   She'll only call you back when she notices you didn't fit the two extra sockets :B-

 

[SBS Dave]

Hi Shiner,

I can do you a small enclosure, fitted with either a 20A, 32A or 40A Compact RCBO, for £17.00 + £3.00 postage + VAT.

Not only does this give you 2-pole isolation and RCD shock protection, it also gives you MCB fault and overcurrent protection to the rating of the RCBO.

If you are interested, contact me on [email protected].

SBS Dave

 

[SBS Dave]

This is what it looks like, c/w earth terminal and labels.

SBS Dave

 

[binky]

never liked those enclosures if trying to intoduce meter tails, just too flimsy albeit price is right. Much prefer the Wylex units but hard to find, not that we use many, so tend to opt for basic garage unit these days.

 

[SPECIAL LOCATION]

never liked those enclosures if trying to intoduce meter tails, just too flimsy albeit price is right. Much prefer the Wylex units but hard to find, not that we use many, so tend to opt for basic garage unit these days.

Do you mean these Wylex enclosures??

http://www.screwfix.com/p/wylex-ip40-insulated-enclosure/32311

:C

 

[steptoe]

I think he means these , also available in  a 4 pole, or a 2pole in a 4way enclosure, means you can fit a main sw/RCD/whatever and an MCB

I use them all the time, prob 2 or 3 a week.