More EICR coding questions.

[westward10]

Forget PRS when it comes to commercial periodics outside of this scope. Code 2 requires "Urgent Attention" and there is no recommended period of time, it is urgent.

 

[Lucien Nunes]

Strictly speaking we should be visualising these cables as a conventional distribution circuit, rather than meter tails, as they are protected by the customer's switchfuse.

32A socket outlets intended for entertainment lighting are often fully loaded. If I go into a venue with my own equipment and I see two 32A sockets, I will check the upstream to make sure the total is not limited to less than 64A (e.g. by other essential load on the same 100A SF) but otherwise use all 64A. The maximum load on this DB therefore exceeds the rating of the distribution circuit but only by a small margin, perhaps 5%. This translates into a 10% excess temperature rise, but probably for a few minutes per year when pushing everything to full for the finale. The cables are likely to be more or less unloaded for 99% of the rest of the time and could be expected to last their full design life. Whilst technically non-compliant, I cannot see any hazard at C2 level (actually I cannot see any hazard.)

IMO a circuit sufficient for the total installed load on a DB is adequately protected against overload by the downstream OCPD, provided it is also adequately protected against faults by the usptream (which it invariably is.) Therefore the board with 44A outgoing is fine on 16mm². If someone wants to come along and install a shower on the board at a later date, they need to check the adequacy of the supply equipment including the distribution circuit, and at that point the CCC of the 16mm² would show up as a factor requiring upgrade.

 

[timhoward]

Lucien's post has made revisit the original information and I now see I made an mistake when I read the original posts- I had believed the design loads quoted were based around the 3A of lighting and an empty 2nd 32A socket, so was mentally adding two maxed out 32A sockets to the totals.
Now I see (as pointed out) that the design loads are within the CCC of their cables I do feel that C2 is over-stating any potential danger.
It's also in the back of my mind that in different circumstances with this all connected nearer the origin reg 433.2.2 would render this compliant (fault protection in place and <=3m conductor length allows overload device to be downstream).
It would probably be best to resolve the issue that could crop up at every inspection and add upstream fusing, as once upon a time someone once shouldn't have fitted the 16mm conductors with an 100A upstream fuse.

 

[brianmoooore]

I see my thread has suddenly sprung to life after lying dormant for a couple of weeks!

My take is that the Method B tails are good for 76A and the Method A ones for 61A.
Design load on the first DB is 32A + 75% of 32A + 75% of 16A +lights = 68A +lights, so just within the Method B tails.
Design load on the second DB is 32A (RFC) + 12A (actual load of water heater) + lights = 44A + lights, which is well within the 61A rating of the tails.

Does anyone agree/disagree with the quote above? I've used a diversity factor (commercial building) of 100% of largest socket circuit + 75% of other socket circuits for the first DB and no diversity for the second, since it only has one socket circuit.
Lighting load on both is minimal - the lighting circuit only serves 3 or 4 lights on each.

 

[timhoward]

It seems fair enough. (If you stuck the 2nd unused 32A socket feed in the cpc bar I think the first DB would be way under the CCC of the supply cable without any diversity.)
I'm not concerned about it's safety at all, it will just always look wrong.
If the main switch on the DB's were two pole 50A RCBO's then it would be an easier argument that an entire CU is a fixed (or at least limited) load! Probably not a practical solution though.