Discuss Why do i need a rewire when i've passed inspection with no issues? in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net

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If there is work to be done and the house is unoccupied then get it done whilst it’s empty. Shop around.
If you do a new consumer unit most will advise on breakers that are more sensitive eg rcbo rather than mob . There is always a chance further work will need to be done when sensitive breakers trip. But then you would want to know of any issues ???
A bit of extra capacity on the cu is always desirable
 
17k sounds a bit steep to me, less it’s a Trump palace and spec, in the middle of London.
Middle of London £17k would barely get you a 1 bed flat Re-wire these days, some of the prices I see banded about this year are eye watering. You only have to look at what Artisan are charging £800 per day + Vat for Re-wire work and that is in Cambridge.
 
My advice, get a proper report done on the existing then get quotes in for any works that are required and any works you would like doing. Always best to get the jobs done whilst unoccupied and during alterations, before decorating, final fixtures and fittings.

Depending on what is required based on the report and what is required by yourself for alterations/additions it may prove more economical to start again. However until you get a proper report done then you are in no real position to know what is the best course of action.

If you get a report done, please feel free to share with us the results.
 
I completely agree with @Intoelectrics, Looking at the results from 2 years ago I'd be surprised if a rewire was warranted but only a decent EICR will tell you.
My top concern from the last testing is that circuit 4 is getting close to being too long (Zs of 1.04 ohms sitting on a B32). It wouldn't be sensible to extend that circuit.
 
I completely agree with @Intoelectrics, Looking at the results from 2 years ago I'd be surprised if a rewire was warranted but only a decent EICR will tell you.
My top concern from the last testing is that circuit 4 is getting close to being too long (Zs of 1.04 ohms sitting on a B32). It wouldn't be sensible to extend that circuit.
Hmmm maybe a spur on a spur in the ring, or is the house that big that you would have a circuit length of 50+ metres on 2.5/1.5 T&E?
 
Hmmm maybe a spur on a spur in the ring, or is the house that big that you would have a circuit length of 50+ metres on 2.5/1.5 T&E?
You forgot to take off the Ze (0.36 in this case). So we're talking about 0.67 ohms worth of actual circuit, so more like 28m of cable which is plausible for a ring final circuit that covers more than one floor.
 
You forgot to take off the Ze (0.36 in this case). So we're talking about 0.67 ohms worth of actual circuit, so more like 28m of cable which is plausible for a ring final circuit that covers more than one floor.
Ah yes my bad! Although interesting on the schedule of results the figure 0.36 is recorded as the Zs? and Not Ze....And the Ipf is quoted as 1.06kA?
 
Ah yes my bad! Although interesting on the schedule of results the figure 0.36 is recorded as the Zs? and Not Ze....And the Ipf is quoted as 1.06kA?
On the 1st page it gives 0.36 as the Ze (twice in fact!). I can't spot where you mean for 0.36 Zs.

The confusion over the 1.06Ka is because the property has TNS earthing. As your profile says you are a trainee I'll elaborate a bit....(hang in there!)

The Ipf is the highest of prospective dead shorts of Live-Earth and Live-Neutral and as this property has TNS earthing the two will differ due to the different sizes of the two cables all the way back to the substation transformer. (If it were TNCS earthing then due to the neutral-earth link in the cut-out the values would be the same)

The path back to the transformer through the neutral has a lower impedance of 0.21 ohms (working backwards from 1060 amps) as it's a bigger wire. This makes sense.
So the maximum fault current Line-Earth is 638 amps (230/0.36) and the maximum fault current Line-Neutral is 1060A.
The installer recorded the higher of the two (correctly).
 
On the 1st page it gives 0.36 as the Ze (twice in fact!). I can't spot where you mean for 0.36 Zs.

The confusion over the 1.06Ka is because the property has TNS earthing. As your profile says you are a trainee I'll elaborate a bit....(hang in there!)

The Ipf is the highest of prospective dead shorts of Live-Earth and Live-Neutral and as this property has TNS earthing the two will differ due to the different sizes of the two cables all the way back to the substation transformer. (If it were TNCS earthing then due to the neutral-earth link in the cut-out the values would be the same)

The path back to the transformer through the neutral has a lower impedance of 0.21 ohms (working backwards from 1060 amps) as it's a bigger wire. This makes sense.
So the maximum fault current Line-Earth is 638 amps (230/0.36) and the maximum fault current Line-Neutral is 1060A.
The installer recorded the higher of the two (correctly).
Im referring to the additional images further along the thread, if you look at image marked cert4 that's where the Zs figure of 0.36 in the 2nd box is. Thanks for pointing the TNS earthing arrangement out, in my haste I neglected to notice that, perhaps ive miscalculated something along here but i made the mistake/error of calculating (230/1.04) 1.04 being calculated on the circuit #4 for the R1+R2+Ze, if that clarifies/muddy's the water..
 

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