What kind of incoming electrical connections are these?

[JohnW2]

Apart from the 'neatness' of one CU, what are the advantages/disadvantages of either option?

Opinions will undoubtedly vary about this.

If the plan would be to have three single-phase CUs all in essentially the same place, then I see little to choose between the two options. However, if (as in my house) it would be more logical to have the three CU's in different parts of the building, supplying 'local' circuits in the respective parts of the house, then three seperate ones would obviously make more sense (as I believe it does for me). Three separate CUs also means that you could switch one entirely off (e.g. to work on it) without losing all electricity in the house.

Another slight consideration, with thoughts of future work on the installation, is that some electricians who do only domestic work might not be very familiar with 3-phase DBs.

Kind Regards, John

 

[ban-all-sheds]

If the plan would be to have three single-phase CUs all in essentially the same place, then I see little to choose between the two options.

I think the partial isolation you mentioned is a factor in favour of 3 x 1-phase, even if they are all in one place.

It's also better if there are multiple RCDs instead of individual RCBOs, and it could make life easier in the future if expansions are needed - only 1 CU to replace instead of a 3P distribution board, or major reconfiguration of it.

 

[JohnW2]

If the plan would be to have three single-phase CUs all in essentially the same place, then I see little to choose between the two options.

I think the partial isolation you mentioned is a factor in favour of 3 x 1-phase, even if they are all in one place. It's also better if there are multiple RCDs instead of individual RCBOs, and it could make life easier in the future if expansions are needed - only 1 CU to replace instead of a 3P distribution board, or major reconfiguration of it.

I essentially agree. In fact, despite what some people seem to think, if there are not to be any 3-phase circuits (and if it's very improbable that any will ever be required in the future), I really can't see any advantage in having a 3-phase DB.

Kind Regards, John

 

[PBC_1966]

Much depends upon the the size and layout of the house, where the service is located, where major loads are in relation to it, etc. If the intake is fairly centrally located and space for the metering/distribution equipment is somewhat restricted, then a single 3-phase board might be quite suitable and neater than having three separate single-phase boards all in the same place. If it's a rambling place with the intake at one end you might be better off running a couple of sub-feeders from two of the phases to other locations around the house and putting single-phase boards at those locations to distribute around those areas of the house, subject to being able to balance the load reasonably across the phases. There's no single "this is the better/best option" answer to this sort of question, as much depends upon the particular circumstances.

 

[ban-all-sheds]

All true.

But this whole discussion started when flameport asserted that there was something wrong per se with 3 x 1P CUs.

If you do have the 3p supply installed, have a proper 3p distribution board fitted.
Any 'electrician' who suggests 3 separate consumer units should be shown the door.

 

[JohnW2]

All true. But this whole discussion started when flameport asserted that there was something wrong per se with 3 x 1P CUs.

Indeed it did - and (albeit as an 'outsider') I still don't really understand what is 'wrong' or 'not proper' about having three separate single-phase (or something 'wrong' about the electrician who installs them), if there is no question of any 3-phase circuits being required.

Kind Regards, John

 

[ban-all-sheds]

Nor I.

 

[PBC_1966]

Ditto.

 

[newconnection]

Everyone - thanks for all your help. Really useful. No doubt I will be posting again for more assistance

 

[wundaboy]

Only thing I can see is missing so far going down the three x 1 phase CU/submain route is a single point of isolation after the meter, which is easily achieved with one of these. Other than that I'd prefer having the three phases as separate supplies - as already stated it means you can perform maintenance whilst still keeping the supply on in most of the property.

 

[newconnection]

UPDATE:

So, 5 flats and 1 landlord supply.

For 'connection 2' shown in the picture in my first post in this thread, this is still in place and will be used for one of the flats and one of the meters will be removed.

For the other 4 flats and 1 landlord supply, a 7 way panel and 5 meters:

So now I am looking for 6 x CUs which are obviously amendment 3 (i.e. metal clad). I don't imagine I need more than a 10 way. Any recommendations?

 

[Iggifer]

Why use the far left cable entry for the far right meter?

Hager. All the way. They do a 5x5 Dual RCD board, Design 10 is the cheap(er) range, and Design 30 is downright fancy. Has integral cable clamps for meter tails.

 

[kai]

It is bad practice to have two incomers in one domestic property - why not get the old one removed? - Just use the new one.....

 

[JohnW2]

It is bad practice to have two incomers in one domestic property ...

It certainly has its downsides - but I'm not sure that I would necessarily classify a building which includes 5 flats as being "one domestic property", would you?

Kind Regards, John

 

[cjard]

Why use the far left cable entry for the far right meter?
.

Because the people that sling these boards together aren't electricians, and judging by mine aren't bit into neatness or logical order either. At least this one is relatively neat, I'll dig out a before and after pic of how eon butchered mine when they came to install a third phase at had been ordered 2 weeks later than the other two