Talk:CU

I have done my edits in the other version of this, however I will add comments here where appropriate.

The upgrades section is already covered in more detail in the changing a cu article.

Same goes for the sections on Upgrading on TT, and working on a CU.

--John Rumm 02:58, 8 March 2009 (GMT)

level of protection

I think this bit is missing the point really.

Fault current protection is required at the origin of the circuit. Overcurrent protection is typically also provided at the origin, but is not actually required to be there. By design one may choose to delegate the overcurrent protection to somewhere else. (i.e. this is not just about inheriting sub optimal situations from old installations)

For example two 16A radials connected to space heaters could legitimately be connected to one 32A MCB if it made more sense to have them controlled together (say both are in one room). If they were wired in 2.5mm^2 T&E then the 32A MCB would provide adequate protection in the event of a fault (e.g. damaged cable etc). However it would not provide protection from overload. In this circumstance the job has been delegated to the FCUs that connect the appliances. The maximum fuse that could be inserted in each is 13A, and the absence of any sockets or other FCUs prevents the maximum load on the circuit exceeding the nominal 26A

--John Rumm 03:08, 8 March 2009 (GMT)

Are we done with this one?

Most of the sections seem to have found a home in one place of another:

Split Load CU - in Consumer Units and basic house wiring

Upgrades - in detail in changing a cu

Upgrading CUs on TT installs - as above

Level of protection - dotted about the place - although its not really a CU specific thing as a circuit protection one.

Live parts - covered in the changing a CU and also in Fuses

Working on the CU - in changing and outside electrics

Trips - in RCD in detail and also Fuses plus other places.

The only one I am not sure about is: MCBs & Fuses - we don't really have a place for this, although it would probably be useful somewhere. I think I might create a dedicated Circuit Protection article to cover selection of protective devices. That could include recommendations such as described here.

--John Rumm 15:12, 14 March 2009 (GMT)

Theres a section in either Fuse or MCB on comparison of the two. But what you propose sounds like a decent idea.

Re this article, once all the sections are dealt with I think the top part of this one should remain, so the phrase 'CU' in aricles directs to here, and this page directs people to the many pages that cover CUs. Otherwise _we_ may know whats where, but the average DIYer looking for CU info is going to be quite hard pressed to find the relevant stuff. NT 22:40, 14 March 2009 (GMT)

Yup, I had missed the MCB one. Between that and the Fuses one they cover most of what would go into a protection one. The only bits one could add within the scope of both is things selecting devices for cascaded use (i.e. ensuring discrimination by calculating let thru energies on the tripping device etc). That might be getting a bit obscure though.

Leaving the header as an intro to the articles is fine. I would suggest creating a redirect for "fusebox" to point at it as well, since I expect this is how the majority of novice users would refer to it.

--John Rumm 23:46, 14 March 2009 (GMT)

A 2nd CU in the garage/workshop isnt unusual, so I can see info on cascaded protection devices being of use. Not all wiki readers are novices or basics readers, only the majority. NT 01:42, 15 March 2009 (GMT)