Electrical Costs

[securespark]

 

[oldbutnotdead]

Interesting.
First one (good news) you have got cpc at the light fittings
Second, is there another section for the night storage heater circuit(s)?
Third (and this info should be available in that report somewhere) is there currently a separate CU for the night store heaters and is it supplied from a different meter?
Looks like matey is gilding the lily with his materials- you've got 6 circuits now plus the night storage (prob 3 at most) so a 14 way RCBO board is over the top, especially if you need a separate board for the storage heaters. That's quite steep for labour up here as well (also NE)

 

[Risteard]

...the Insulation Resistance section is all wrong. Testing at 250V is not really right, and the identiocal 9and 'odd') results for all ccircuits is 'interesting'!

Not really true. 250V is legitimate in certain circumstances, although my preference would certainly be for 500V where possible. I certainly would not be insulation testing between live conductors during a periodic inspection, however.

The fact that the results are the same across all circuits is not unusual at all - it simply indicates that the test was carried out globally across all circuits in parallel - which in fact is the correct way to conduct the test, as BS 7671 clearly states that the insulation resistance is to be measured for the entire electrical installation (or individual distribution circuit with all final circuits connected for larger installations). It is not for one final circuit.

 

[SUNRAY]

This is of a one bedroom flat, 3 MCBs on the left are night storage heaters, 5 on the right are the rest.

I changed it at change of tenant and change of agent to a single 14w CU for:
1) Create a single main switch which seems to have become an agents requirement.
2) Add all RCBO's for the 24H circuits.
3) Add RCD to E7 circuits.

The wooden enclosure was then cleaned, painted and replaced around the CU.

This is a low cost 'Pro-Elec' [CPC] at a total price of £162 at todays prices. I will always suggest a better quality unit like Hagar linked to for about £200 as the internal space is so much better than this, however this was chosen as it was one of the very few that fitted in the cupboard without having to extend any cables. E7 doesn't have to be 2 individual CU's

So yes I reckon your quoted materials cost of £600 is at least double what it should be.

 

[JohnW2]

Not really true. 250V is legitimate in certain circumstances, although my preference would certainly be for 500V where possible.

I very much doubt that the 'certain circumstances' would apply to all dinal circumstances and, if it only applied to one or two, I would have thought that it/they should be tested separately, so that the other circuits could be tested at 500V?

I certainly would not be insulation testing between live conductors during a periodic inspection, however.

They seem to have done so.

The fact that the results are the same across all circuits is not unusual at all - it simply indicates that the test was carried out globally across all circuits in parallel - which in fact is the correct way to conduct the test, as BS 7671 clearly states that the insulation resistance is to be measured for the entire electrical installation (or individual distribution circuit with all final circuits connected for larger installations). It is not for one final circuit.

Fair enough but, when that's what's been done, it seems rather misleading to document it in the way they have done (I suppose partially the fault of the form) - If I'd done that, I'd personally be inclined to bracket all the circuits together and record just one figure, rather than give what appear to be separate results for each circuit (albeit I could only do that, with the standard form, if I were completing it manually!)!

Anyway, my comment about the sockets circuit remains. It's either a ring final or it's not. If it is not, the cable is too small (for the 30A fuse); if (as I suspect is probably the case) it is, then the loop 'continuity' test is not "N/A"!

 

[SimonH2]

I use a separate line on the form for the "whole installation" IR test.

 

[JohnW2]

I use a separate line on the form for the "whole installation" IR test.

Per what I wrote, that would certainly make a lot more sense, and be less potentially confusing (and/or 'incorrect').

Kind Regards, John