Can Zs at DB ever be less than the Zs of the feeding circuit?

1. No 'steeple', but there is a 'tower'.  Interested to know how that affects matters (I mean that genuinely - it's not intended to be a provocative question :-)

It has not had any floors 'added' on top, but it did have an internal floor 'inserted' in the middle some 10 years ago, and that would have required considerable new wiring added at the time plus, I would guess, numerous structural steel support beams.



2. TNC-C-S is declared on the EICR;



3. You will see from the above that 'N/A' has been recorded for all Main Bonding.


4. It is a self-contained building, and I believe the meters are all contained within the building.


My main concern is regarding feeder circuits to DB GF2.(not my original question, but the reason for my trying to check other details on the report);

The EICR records as follows;

DB GF2 is supplied from 'DB MP1 Circuit No 2TP' via a 25mm^2 live conductor, 16mm^2 earth and MCCB rating 160A;



DB MP1 circuit 2 records that GF2 is fed by 100A MCCB via 35mm^2 live conductor and 25mm^2 cpc;



and his observations in the EICR state;


and he has quoted to 'To supply and install new 25mm 3 Core Armoured cable from Main Electrical intake to

Distribution Board GF2. Disconnect and cut out where possible redundant feed to GF2'.


On being challenged that he has got his GF2's and GF3's mixed up, and what he says in his conclusions does not match what is recorded in his EICR, the inspecting contractor (who issued the EICR) is then saying;

"Sorry there was an error on my observations.
 
GF2 is fed from MP1 not GF1.
 
GF2 is labelled in MP1 as “Boiler Panel” but it feeds GF2 which the feeds Boiler Panel.
 
This is on a 32a MCB. GF3 is fed from a 62a MCB in GF2.
 
We  are not in the business of making recommendations for cables that are not necessary, our proposal is to give you a safe and fully compliant electrical installation.
 
Please confirm you still wish us to continue with these works."


This still does not match what his EICR says, raises all sorts of questions regarding how accurate the EICR is, and whether it is safe to rely on what he is recommending.  I am thinking his EICR is just too scrambled and full of inconsistencies to be taken as credible.

Or am I missing something?


Many thanks for your interest - it is much appreciated.

1. No 'steeple', but there is a 'tower'.  Interested to know how that affects matters (I mean that genuinely - it's not intended to be a provocative question :-)

It has not had any floors 'added' on top, but it did have an internal floor 'inserted' in the middle some 10 years ago, and that would have required considerable new wiring added at the time plus, I would guess, numerous structural steel support beams.



2. TNC-C-S is declared on the EICR;



3. You will see from the above that 'N/A' has been recorded for all Main Bonding.


4. It is a self-contained building, and I believe the meters are all contained within the building.


My main concern is regarding feeder circuits to DB GF2.(not my original question, but the reason for my trying to check other details on the report);

The EICR records as follows;

DB GF2 is supplied from 'DB MP1 Circuit No 2TP' via a 25mm^2 live conductor, 16mm^2 earth and MCCB rating 160A;



DB MP1 circuit 2 records that GF2 is fed by 100A MCCB via 35mm^2 live conductor and 25mm^2 cpc;



and his observations in the EICR state;


and he has quoted to 'To supply and install new 25mm 3 Core Armoured cable from Main Electrical intake to

Distribution Board GF2. Disconnect and cut out where possible redundant feed to GF2'.


On being challenged that he has got his GF2's and GF3's mixed up, and what he says in his conclusions does not match what is recorded in his EICR, the inspecting contractor (who issued the EICR) is then saying;

"Sorry there was an error on my observations.
 
GF2 is fed from MP1 not GF1.
 
GF2 is labelled in MP1 as “Boiler Panel” but it feeds GF2 which the feeds Boiler Panel.
 
This is on a 32a MCB. GF3 is fed from a 62a MCB in GF2.
 
We  are not in the business of making recommendations for cables that are not necessary, our proposal is to give you a safe and fully compliant electrical installation.
 
Please confirm you still wish us to continue with these works."


This still does not match what his EICR says, raises all sorts of questions regarding how accurate the EICR is, and whether it is safe to rely on what he is recommending.  I am thinking his EICR is just too scrambled and full of inconsistencies to be taken as credible.

Or am I missing something?


Many thanks for your interest - it is much appreciated.