New metal 2 way unit fed from old Plastic 10 way consumer - Ok or not ?

[alPudsey]

Hi,

I have just had work done but not sure if this is acceptable as i am having doubts.

I have an existing 10 way 'Plastic' consumer unit, fitted in 2004.
Electrician has now added a new 2 way METAL unit to feed the dormer Ring mains and Lights & the tails are fed to inside the old 10 way (not from a splitting Henley block).

Even if it is correct, would they have to test the old consumer unit and circuits as well ? , as new one is being from the internals of the old one ? Some of the existing circuits did trip a few times when he was working on it, hence why Im asking about 'testing' of old one

Can you feed a new consumer unit directly from the inside of exsiting old one ? If yes, would installation testing have to include the old consumer too or not ?

 

[IAmSparkytus!]

This 3 meter rule/ reg is often mentioned. There is no reg that states this.
in some cases 10 meters is perfectly acceptable in others it’s not.

Agree there's no reg but it's often mentioned that this is stipulated by the DNO - is this not the case? This is what I've heard from other people on here but never actually heard it direct.

 

[IAmSparkytus!]

You should be using phase blocks to split feeders in my book...

I've seen it before and I don't like it

Agreed. Can't imagine the terminals would get a very good connection on two 25mm or 35mm conductors together

 

[Deleted account]

Agree there's no reg but it's often mentioned that this is stipulated by the DNO - is this not the case? This is what I've heard from other people on here but never actually heard it direct.

I also used the think the 3 meter rule applied for th3 same reason you thought. I’d heard it from various people.
I only discovered it wasn’t an actual reg when I came across an installation that had 10 meter tails. I contacted the DNO and they said they where happy with this arrangement. So I looked into it deeper and found no written stipulation.


as for original poster.
it’s fine to take a feed from a plastic CU to a metal CU.
however if tails (16mm or 25mm) are being taken out of the plastic main switches intake, I’d personally not do it.

however-
ive seen this done in industrial and was surprised when I did, but decided the main tails to both CU’s are protected by the incoming. However I’ve never seen this in domestic.
conclusion
can’t see a big issue with this, but I personally would not do it.

 

[alPudsey]

I also used the think the 3 meter rule applied for th3 same reason you thought. I’d heard it from various people.
I only discovered it wasn’t an actual reg when I came across an installation that had 10 meter tails. I contacted the DNO and they said they where happy with this arrangement. So I looked into it deeper and found no written stipulation.


as for original poster.
it’s fine to take a feed from a plastic CU to a metal CU.
however if tails (16mm or 25mm) are being taken out of the plastic main switches intake, I’d personally not do it.

however-
ive seen this done in industrial and was surprised when I did, but decided the main tails to both CU’s are protected by the incoming. However I’ve never seen this in domestic.
conclusion
can’t see a big issue with this, but I personally would not do it.

Thank you