Would you energise a modified circuit without RCD protection

[Octopus]

Pretty much what the title is.

Asked to do a job, don't have time to do the board change but could make the changes to the kitchen socket circuit...

So testing of sockets would be done, but no RCD protection (very old board so no upgrade path) until CU is changed in Jan

Tin hat on!

Pop corn at the ready.

 

[sevuk]

Yes, an RCD in an enclosure close to the CU is a fairly standard way to provide RCD protection for a single circuit. Not an adaptable box though, user access to the RCD is preferable of course.

What if you jigged it out and mounted it so the breaker extruded through the lid?

 

[Andy78]

What if you jigged it out and mounted it so the breaker extruded through the lid?

I've always just used small din rail enclosures.

 

[sevuk]

Yes, an RCD in an enclosure close to the CU is a fairly standard way to provide RCD protection for a single circuit. Not an adaptable box though, user access to the RCD is preferable of course.

I'm struggling to get my head around how this would work in a ring. Radial is straight forward, a regular 63amp 30ma rcd could be connected downstream of the fuse below the board with the out going circuit going out, but connecting two cables in the top then two in the bottom just sounds bad to me, 6mm in the top and the ring in the out going?

 

[Andy78]

If it was jigged out and mounted so it extruded through the surface that would be alright wouldn't it?

I'm struggling to get my head around how this would work in a ring. Radial is straight forward, a regular 63amp 30ma rcd could be connected downstream of the fuse below the board with the out going circuit going out, but connecting two cables in the top then two in the bottom just sounds bad to me, 6mm in the top and the ring in the out going?

If done that way then the ring would emanate from the RCD, the RCD being fed from the OCPD. Nothing wrong with that.

 

[sevuk]

If done that way then the ring would emanate from the RCD, the RCD being fed from the OCPD. Nothing wrong with that.

Are you saying you would feed the RCD with correctly sized conductors and earth (maybe a bit of 6mm for belt and braces) and then start the ring from the outgoing of the RCD? That's probably how I'd want to do it. What sounds wrong to me is if the RCD was fed from two ring cables, mostly because it's so short.

 

[Andy78]

Are you saying you would feed the RCD with correctly sized conductors and earth (maybe a bit of 6mm for belt and braces) and then start the ring from the outgoing of the RCD? That's probably how I'd want to do it. What sounds wrong to me is if the RCD was fed from two ring cables, mostly because it's so short.

Whether you fed a supply to a 32A ring with 2x2.5mm, a 4mm, or a 6mm, it would be fine.

 

[sevuk]

Whether you fed a supply to a 32A ring with 2x2.5mm, a 4mm, or a 6mm, it would be fine.

Can't back up technically why the RCD couldn't be fed in two 2.5 as the current will be divided, as the lengths are the same.

I must be getting cable paranoia, it's inherited, I did my time working for a worried man, and likewise so's my dad...

 

[wsoppitt]

Trouble is as stated in earlier post the homeowner is confused as to why she needs a fuseboard change anyway.Does this not lead the way to her changing her mind and saving expense for a job that she doesn't want done .the point is if you temporarily adapt then she dicided that she doesn't want it changed you will still have to supply cert for works done and probably a 2nd visit to make it comply.just do it right first time .

 

[Chris1234]

I’ve not read everything so may have missed it.
Can’t you fit a small box and fit a RCBO in it close to the DB?

 

[sparksfly]

I have done this... no problem in the real world. So long as the test results are ok. If the customer does not want a CU or circuit upgrade with RCD next year then issue a cert noted with the non-compliance of BS7671 and recommended upgrade to circuit. Covered yourself.