Quick Question - Max Permitted Zs Values

[byrnie_2004]

On an Installation Cert in the 'Max Permitted Zs' column should i put the tabulated values in the regs or should i put the corrected values(x0.8 rule of thumb)????
My guess would be corrected values as that would be max zs at ambient temperature at the time of test?
Cheers peeps,

Dan

 

[Deleted member 26818]

As I understand it, you are expected to put in the uncorrected tabulated values from BS7671.
If thes are NICEIC or Napit forms, I believe you are also expected to put in the uncorrected measured values.
Bit weird, but that's the scheme providers for you.

 

[telectrix]

general opinion is to enter the brb ( uncorrected ) figures on the test sheet, but the readings you get should be below the corrected figures. very rare to see cables reaching max. temp. of 70 deg. anyway

 

[byrnie_2004]

cheers, would make sense as maximum permitted zs

 

[telectrix]

but if it's a TT system with RCD protection, you can enter 1667.

 

[ringer]

but if it's a TT system with RCD protection, you can enter 1667.

Just on TT systems, or on any system so long as the circuit concerned is protected by a 30mA RCD?

PS should that be 1667 so long as the rcd is rated to trip at 30mA?

PPS these are both questions, not statements.