CU Question

[Sparky83]

Hi guys,

Have a quick question, which i cant find the answer too.

Brief history as to why im asking...

A mate of mine got someone around to dchange his DB, i would have done it but im not Part P as i dont need it so he got someone else, anyway they have been and done it. He sent me a picture earlier today of the new DB, its appears to be a 16th edition single RCD board. There is 7 MCB's protected by the RCD and 2 that are not protected by any RCD.

He questioned if this was right, and after asking him some questions it seems that the 2 circuits that are not protected are the lighting as its one circuit for the whole house and the other is the boiler.

The boiler is surface the DB up to the cupboard upstairs so im guessing this is fine. But the lights are clearly not surface, and they aint 50mm in the wall nor in earth metal conduit.

Other than that is there a regulation that states one RCD is not right? I know most boards that are 17th ed ones come with 2 seperate RCDs, is this just good practie or is it a requirement?

Thanks
S

 

[spark 68]

Other than that is there a regulation that states one RCD is not right? I know most boards that are 17th ed ones come with 2 seperate RCDs, is this just good practie or is it a requirement?

It is a requirement now, see reg 314.1, it was always a requirement IMO, just misunderstood (implied) in the 16th ed., and stated in the 17th.

You could stick an RCBO on the non RCD side for the lighting.

When I install twin RCD boards, I put the upstairs lighting on the same side as the downstairs sockets, and vice versa for the otherside, so I will always have power up or down in the event of an RCD trip.

Edit: there are some pics in the OSG p23-25

 

[Sparky83]

Thanks great, thanks for that I'll have a look.

Totally agree with the up/down powering and lighting being mixed up, this is what i would do to, and again as he has only 1 lighting circuit i'd RCBO that.

 

[Engineer54]

Seems your mate has been sold a duck here!!

And one that doesn't conform to current standards. And these Scam providers are supposed to verify the competence of an electrician ...pure fantasy on their part!!

 

[Sparky83]

And these Scam providers are supposed to verify the competence of an electrician

Funny you should say that as my mate asked if when the certificate is produced wont someone notice and quiery it......

then he said wont the Part P people notice when they issue the Part P cert....

I said no to both points and he then asked whats the point in Part P then to which i couldnt really answer as this is a prime example of work being carried out and not correctly but its all ok unless it happens to be one of the jobs the inspector wants to see, which you can bet your life it wont!