Garage Consumer Units

[Jonny72]

Ok, most new Consumer unit seem to come with a 63A RCCB and two MCBs. Most house consumer units now will also have RCD of some type be it a dual board or RCBOs. I know there can be issues with Selectivity having an upstream and downstream RCD. One Should really be S type (more expense). Should one 30mA RCD be removed? I am really not bothered which RCD activates as long as one does in event of providing additional protection. Just seems to add to cost replacing one with a simple on/off isolator. I am just concerned neither work.

 

[Jonny72]

Ok, most new Consumer unit seem to come with a 63A RCCB and two MCBs. Most house consumer units now will also have RCD of some type be it a dual board or RCBOs. I know there can be issues with Selectivity having an upstream and downstream RCD. One Should really be S type (more expense). Should one 30mA RCD be removed? I am really not bothered which RCD activates as long as one does in event of providing additional protection. Just seems to add to cost replacing one with a simple on/off isolator. I am just concerned neither work.

I am referring to garage distribution boards fed off main boards

 

[nicebutdim]

Either seek to avoid RCD protection at source or buy a mainswitch board for the garage.

Not sure how you'd justify replacing one RCD in a dual board with a Type S device or removing one RCD entirely.

 

[Jonny72]

Either seek to avoid RCD protection at source or buy a mainswitch board for the garage.

Not sure how you'd justify replacing one RCD in a dual board with a Type S device or removing one RCD entirely.

What is likely the happen with two 30mA RCDs upstream/downstream. Could you loose all additional protection or will unable to predict which will activate?

 

[nicebutdim]

What is likely the happen with two 30mA RCDs upstream/downstream. Could you loose all additional protection or will unable to predict which will activate?

No selectivity between devices, so in theory either could trip. In reality it's always going to be whichever is most inconvenient - Murphy's Law dictates you'll take out the upstream device and half the house.

From a regulatory perspective the installation would be non-compliant.

 

[Jonny72]

Ok thanks. I will try and get a wee sub board without RCD device as would be easier than fitting Escos etc and rewiring consumer bits of consumer unit. Thanks for you help mate.

 

[Dustydazzler]

When I do a new garage / add power to a garage , I put the rcd in the house and assemble a small main switch board for the garage with what ever MCBs I need in there.

 

[Jonny72]

Yes that's what I am going to do. Believe it or not it actually more expensive than just buying a complete garage unit - but they all have RCDs. Thanks.

 

[westward10]

Are you going to incorporate surge protection into it?

 

[Dustydazzler]

Yes that's what I am going to do. Believe it or not it actually more expensive than just buying a complete garage unit - but they all have RCDs. Thanks.

just buy the cheapest garage board , buy a seperate 80a switch and swap it out. in the grand scheme of a job it adds about a tenner to the material cost