adiabatic equation, help / advice

[claret73]

How would this be done in a practical sense? Taking the example of 3 flats and each flat had Gas & Water, would you terminate 6x Bonding conductors back to a Multiple earth block at the Intake and feed your 16mm MET to the Main CU from that also?

Just done a testing exam at College & the sub board was protected at the Main CU by an RCBO. The Sub CU had MCB's no RCD Protection. I would think in a situation of the flat's CU it would require RCD Protection under current Regs...

 

[Tapouchoke]

Hi guys what we did was would you all agree ?????

As the bonding had been previously installed in the flat,
Therefore, the 6ml cpc would then have been too small as a MET
As a result, We Run a 16ml earth from the MET @the incomer in the basement to the flat.as per table 54-7

Alternatively
The adiabatic equation worked out as 6ml would be enough
However, we then could have run x2 MEBC for gas and water from the MET to the flat

Nevertheless the 16ml t&e should have been rcd protected it was listed as a comment ont the cert we would have given it a code 4

Thanks for posts

 

[Guest123]

Spot on mate.