Individual RCBO

[trebor12345]

Hi

I need to check what the electrical requirements (17th addition and Part P) are for RCBO's on a new kitchen extension.

Using the existing house Consumer Unit with one 100Amp 30ma RCBO.

Do all the different new kitchen circuits i.e Ring Main, Cookers (x2), Indiuction Hob, Lighting, Smoke/Fire Detectors, etc require their own individual RCBO? Or is one single RCBO (30ma 100Amp) supplying all circuits acceptable?

Thank you for your replies.

 

[Leesparkykent]

There is not point putting RCBO's in series if they are both 30mA. Are you sure the upfront device is an RCBO and not an RCD?

 

[Pat H]

You need 30ma RCD protection so an 100A RCD or RCBO achieves that but its not ideal as you risk nuisance tripping and everything going down.
The smoke fire detectors shouldn't be losing power qhen the main earth leakage protection trips.
Individual RCBOs is a better solution.

 

[Octopus]

I would explain the issues facing an installation with a single upfront rcd plunging into complete darkness......

And then see if they would agree to a cu upgrade and then go for RCBO's.....

Don't forget about making sure that earning and bonding are up to scratch.

 

[trebor12345]

There is not point putting RCBO's in series if they are both 30mA. Are you sure the upfront device is an RCBO and not an RCD?

As far as I can see the device is capable of breaking at a 100 Amp load with a 30ma leakage trip. Am I correct that this is is an RCBO?

 

[Octopus]

As far as I can see the device is capable of breaking at a 100 Amp load with a 30ma leakage trip. Am I correct that this is is an RCBO?

In one word no. Sounds like an rcd. What make of cu is it?

Can you upload a picture?

 

[Barry White]

Without seeing the unit its hard to confirm but it sounds like that it is. Loads of houses wired like that but its not a good system.
What type of earthing is it?

 

[GMES]

I would explain the issues facing an installation with a single upfront rcd plunging into complete darkness......

And then see if they would agree to a cu upgrade and then go for RCBO's.....

Don't forget about making sure that earning and bonding are up to scratch.

It's always about the money with you !!

 

[westward10]

Agree with the others here, can you actually get a 100A rcbo. Like already said can you post a picture.

 

[trebor12345]

I think you are right it's an RCD, so my mistake. So whats the difference between a RCD and RCBO?

 

[GMES]

I was just going to say he may have an Rccb in his head

 

[westward10]

An rcbo is a combination of an mcb and an rcd so offers overcurrent and additional rcd protection. Your rcd only gives the rcd protection.

 

[Octopus]

I think you are right it's an RCD, so my mistake. So whats the difference between a RCD and RCBO?

View attachment 34137

Given how old that box is I would deffo be talking to the customer about a CU replacement....

 

[trebor12345]

So the device in the picture is a RCD which provides protection against any earth leakage, is that right? So the individual breakers (one show in the right of the picture) provides the overcurrent protection, is that right?

 

[Leesparkykent]

So the device in the picture is a RCD which provides protection against any earth leakage, is that right? So the individual breakers (one show in the right of the picture) provides the overcurrent protection, is that right?

yeah that's correct.