Kitchen spurs

[leepy]

Just helped a friend rip out his old kitchen units we found that whoever fitted kitchen / spark had spurred 8 double sockets of one socket these sockets were feeding dishwasher , washing machine , freezer fridge by reading other post on here that's a big no.

 

[telectrix]

1 outlet (single or double) spurred off a ring final doesn't require fusing.

 

[MattyHodge]

Good stuff. Thanks - help appreciated.

 

[telectrix]

Another unqualified DIYer, best he gets in a part P electrician.

a bit harsh, mate, without full knowledge of the poster's experience/situation etc.

 

[MattyHodge]

I did think that, but no harm done and I have the answers I need, so thanks to both of you.

 

[Mark_Burgess]

Take a look HERE and download the PDF (it is safe), scroll down the PDF and you will see the arrangements of regulation 433.1 that we have to adhere to.

 

[telectrix]

if you can get hold of the BS7671, in the red version page 362 gives all the answers on spurring off a ring final circuit.

 

[JONOXNAM]

Yep, fair do's, which is why I've been doing this up until now with the help of an NICEIC accredited electrician. I don't want to hurt anyone either!

Am I right that if I have a spur with just one socket on it that I don't need to fuse the spur? I would wait till he gets back from holiday, but I need to get this done. I'm going to get him to check everything once he's back before I switch anything on, but hope you can help and thanks.

Yep one socket spur from a ring main is OK as the 2.5mm cable can handle that, but there is a rule that the spur cannot be more than 1/8th the length of the ring but you also have to consider that the cable can dissipate its heat wherever it is run.

As with everything this is to do with safety, I will explain something that I think sparkys learn in the first year at college as it does not sound like you have done any cable calcs:
A 2gang 13A socket could draw 26A down the spur cable - so if you run 8 double sockets (I can't remember if you said 8 doubles or 8 total) that's a max potential of 8accesories x2socketsx13A in the plug fuses = 512A so you will blow your circuit protective device (the MCB etc in the Consumer Unit), however the real problem would come if you run the 8 double sockets with say just 3 amps each = 8x2x3A = 48Amps which is far more than your 2.5 can handle and will make it catch fire and your house and you in bed! now you will say the circuit protective device is a 32A so it will go right? But in a domestic dwelling you will expect a type b protective device typically, that could happily sit there with 48A amps for a while as a type B device has a 3-5x tripping characteristic which means to make it blow nice and fast you could in the worst case scenario need 32Ax5 = 160A... so yes your house could burn down if you install 8 double sockets so get a sparky in...

 

[MattyHodge]

Don't know where you got the 8 sockets from (certainly not from me). There will be the final ring circuit of 3 double sockets. Off that there are two spurs (one fused, one unfused) - fused for the cooker hood and under cupboard lighting, and unfused for the fridge (this will be a single socket).

There are two feeds into the kitchen - one will be used for the above and the other for a smaller ring for the cooker isolater and the boiler.

 

[micknew]

Very good post Jonoxnam.

 

[telectrix]

There are two feeds into the kitchen - one will be used for the above and the other for a smaller ring for the cooker isolater and the boiler.

i would use a dedicated 6mm radial for the cooker isolator, and spurr off the socket rfc (3A fcu)for the bolier​

 

[MattyHodge]

OK and thanks again.

 

[Specialist]

Yep one socket spur from a ring main is OK as the 2.5mm cable can handle that, but there is a rule that the spur cannot be more than 1/8th the length of the ring but you also have to consider that the cable can dissipate its heat wherever it is run.

As with everything this is to do with safety, I will explain something that I think sparkys learn in the first year at college as it does not sound like you have done any cable calcs:
A 2gang 13A socket could draw 26A down the spur cable - so if you run 8 double sockets (I can't remember if you said 8 doubles or 8 total) that's a max potential of 8accesories x2socketsx13A in the plug fuses = 512A so you will blow your circuit protective device (the MCB etc in the Consumer Unit), however the real problem would come if you run the 8 double sockets with say just 3 amps each = 8x2x3A = 48Amps which is far more than your 2.5 can handle and will make it catch fire and your house and you in bed! now you will say the circuit protective device is a 32A so it will go right? But in a domestic dwelling you will expect a type b protective device typically, that could happily sit there with 48A amps for a while as a type B device has a 3-5x tripping characteristic which means to make it blow nice and fast you could in the worst case scenario need 32Ax5 = 160A... so yes your house could burn down if you install 8 double sockets so get a sparky in...

Hi Jon: Think your getting things a bit confused mate, the O/P was talking about 8 sockets not Matty.

 

[JONOXNAM]

Don't know where you got the 8 sockets from (certainly not from me). There will be the final ring circuit of 3 double sockets. Off that there are two spurs (one fused, one unfused) - fused for the cooker hood and under cupboard lighting, and unfused for the fridge (this will be a single socket).

There are two feeds into the kitchen - one will be used for the above and the other for a smaller ring for the cooker isolater and the boiler.

Yep apologies I must have confused your post with the initial post, hopefully some of the theory is of help anyway to help you understand what needs fusing....