NICEIC Certification Scheme Consumer Unit Installation Up to Scratch??? NICEIC approved Installer.

[Richard Burns]

Cmax is defined in guidance note 6, but not in BS7671, as far as I know; the value of 1.1 (and 0.95) is taken from a cenelec technical report "Determination of cross-sectional area of conductors and selection of protective devices" in 2011.

 

[Ian1981]

Cmax is defined in guidance note 6, but not in BS7671, as far as I know; the value of 1.1 (and 0.95) is taken from a cenelec technical report "Determination of cross-sectional area of conductors and selection of protective devices" in 2011.

It's just 230v x 1.1 is 253v. It's the electricity safety quality and continuity regulations which allow +10% to -6% of 230v
230v +10% is 23v
230+23v is 253v 230x 1.1 =253v
But yeah cmax isn't in bs 7671 unless I've missed it.

 

[goasis]

Despite all the discussion, going back to the op, there def seems to be some issues with the certification,
if the bonding box is ticked, but there isn't any (and they've been charged) that's an issue
I can't see why you wouldn't measure and record a ze.
They obviously haven't done any zs testing either.
Externally at least, the cu sounds like a right lash up.
All makes you wonder what else they have bodged their way through.

 

[Pete999]

Thanks everyone. Plenty for me to think about which is exactly what I need!

My understanding is any incoming metal service pipework needs to be earthed regardless? Incidentally, just found out my friend was charged for the bonding and meter tails upgrade whatever the requirements are!

Bonded not earthed

 

[Strima]

Hopefully it's been sorted now as they've had two years...

 

[goasis]

Hopefully it's been sorted now as they've had two years...

That's weird, I hadn't noticed, but it had appeared near the top of my lists of threads.... Oh well!

 

[telectrix]

That's weird, I hadn't noticed, but it had appeared near the top of my lists of threads.... Oh well!

maybe it happens when 1 or more members view the thread but don't post???