Just some questions

[bendywendy]

Visited my parents today and they were proudly showing off their new consumer unit. (guided tours, tea and digestives 50p a time). It appears to have been done all legit and they have paperwork but I have a few questions. I have read in various posts that there should be a 100a DP isolator before the CU. There isn't one in this installation. Is this a requirement of the regulations or a best practice option. The consumer unit is a split load type and does have a 100a DP isolator in addition to the RCCB (?). Is there any requirement to have a RCD on the consumer unit as opposed to the DP isolator? My parents have a stairlift and this has been wired into the RCCB side of the CU. Is this right? I have read that some appliances such as fridges and freezers should not be on the RCCB side of the CU in case it was tripped. I would imagine this should apply to a stairlift in case they are stranded half way up the stairs a la Brian Potter.

 

[Adam_151]

Visited my parents today and they were proudly showing off their new consumer unit. (guided tours, tea and digestives 50p a time).

I suppose its slghtly better than the holiday snaps...

It appears to have been done all legit and they have paperwork but I have a few questions.

I'll try and answer them for you

I have read in various posts that there should be a 100a DP isolator before the CU. There isn't one in this installation. Is this a requirement of the regulations or a best practice option.

Its not a requirement if there is only one CU, if there is more than one CU its a more debated point, but I'd say you shouldhave in that case, an isolator is also usful for when swapping or adding CUs, but in your case there deffo isn't anything saying it should have one, whether or not you have one is your choice

The consumer unit is a split load type and does have a 100a DP isolator in addition to the RCCB (?). Is there any requirement to have a RCD on the consumer unit as opposed to the DP isolator?

No need for an RCD incommer on a TN system

My parents have a stairlift and this has been wired into the RCCB side of the CU. Is this right? I have read that some appliances such as fridges and freezers should not be on the RCCB side of the CU in case it was tripped. I would imagine this should apply to a stairlift in case they are stranded half way up the stairs a la Brian Potter.

I'd imagine you are right on this one, maybe the stair lift makers ask for RCD protection? You could phone the CU installer and ask why he put it on the RCD side and possibly have it moved?

 

[Lectrician]

We install points for a stair lift company prior to them arriving to install the lift. They spec an RCD for the supply, and it doesn't have to be a dedicated circuit.

I hate additional DP isolators in the tails. Takes up more space, more to go wrong, and once a CU has been changed, the next time you change it will be when it is of an age where it needs to be changed......and by then, so will the additional DP isolator. Waste of money, time and wall space.

Has the main equipotential bonding been upgraded if not present?? IE, 10mm atleast earth cable to gas and water, where i enters the building?





A photo of the CU from inside and out and would allow us to give you a tick or a cross on the quality of the install.

 

[bendywendy]

Thanks for the replies chaps. Re: the earthing. Yes this all looks new. I suppose it is a sound installation and it is more a case of a little knowledge being a dangerous thing (with regards to me). My parents are in their seventies, but fiercely independant and don't seem to consult anyone about anything. I suppose we worry too much. In this case the electriciean came reccomennded by an uncle. Apparently the fuse holder for the shower on the old consumer unit had overheated and fallen apart. Of course we find all this out afterwards. Once again thanks for taking the time to reply.

 

[securespark]

Just to settle the RCD issue....have your parents got a supply cable from overhead with a seperate earth from a rod in the ground?

 

[Lectrician]

Just to settle the RCD issue....have your parents got a supply cable from overhead with a seperate earth from a rod in the ground?

LOL


FORGET the overhead myth.

A supply can easily be TT if it overhead or otherwise presented to a property......and a TN-C-S / TN-S supply can be overhead/underground.






I would ask th OP if there is sign of an earth cable entering the service fuse