After a New Consumer Unit, now I need EICR & 100A DP Isolation Switch

[i3_happy]

Trying to organise a CU replacement at home. It's a 1930s property. It's got a 10way CU but with no RCD protection.

Was after a larger unit with full RCBOs. Every Sparky I've spoken to has varied in their suggested plans.

1) Some say do an EICR first, others happy to just go straight with a new CU. EICR seems to add a big upfront cost.
2) Some mention DP RCBO, others don't.
3) One said for Building control notification, I've have to check the date on your smoke/heat & carbon monoxide alarm (?).
4) One said gas/water pipe bonding would be required and it's extra
5) One said, I'd have to get an isolator switch fitted by my supplier before the CU can be replaced. Currently there is only a mains fuse for isolation. The CU and mains fuse are both next to each other.

Prices vary for 1, 2, 3 significantly, I mean the most expensive quote is literally double the cheapest quote!

Any advice would be appreciated as this is driving me nuts!

 

[davesparks]

Can the water (hot/cold) and heating flow pipes be cross bonded (interlinked). This cross bonding would happen under the comobi boiler with is not near the CU

They can be, but it wouldn't achieve much as they will already all be electrically connected together via the metalwork of the boiler.

 

[i3_happy]

Why?

If that is the best overall design option then you should accept that.

If it is better to have RCBO at the CU and replace ageing RCD at the outdoor locations then fine, but that is not an argument for/against MCB at the CU as such.

Thanks for the feedback.

My comment was related to a point made earlier....by going the MCB route there would be no RCD protection on the cable between the indoor and outdoor CU. It's probably at least 10m long and just a normal cable - not SWA.

 

[davesparks]

Thanks for the feedback.

My comment was related to a point made earlier....by going the MCB route there would be no RCD protection on the cable between the indoor and outdoor CU. It's probably at least 10m long and just a normal cable - not SWA.

What type of cable is it and how is it installed?

Does it need RCD protection and would it actually be achieving anything if it was provided?

 

[i3_happy]

Just seems like a standard cable out of the CU, chunkier then the others.

Not sure how it gets outside, possibly behind the kitchen units.

 

[pc1966]

Just seems like a standard cable out of the CU, chunkier then the others.

Not sure how it gets outside, possibly behind the kitchen units.

If you are not certain it is safe from DIY nailing, etc (i.e. if it could be hidden less then 50mm from the surface of a wall/flooring/etc) then it will need RCD protection. Here your best choice is an RCBO at the CU and then whatever at the out buildings.

Leaving the existing RCD there is not a big deal, not ideal perhaps, but not such an issue as worth a lot of work to change it unless you are making changes anyway.

 

[i3_happy]

If you are not certain it is safe from DIY nailing, etc (i.e. if it could be hidden less then 50mm from the surface of a wall/flooring/etc) then it will need RCD protection. Here your best choice is an RCBO at the CU and then whatever at the out buildings.

Leaving the existing RCD there is not a big deal, not ideal perhaps, but not such an issue as worth a lot of work to change it unless you are making changes anyway.

Thank you, that's a really helpful post, nice & clearly stated and helps me clear up a lot of confusion on this matter.