RFC testing , downstairs ring going upstairs to a long radial

[jeffelectric]

so end to end L-L 0.4 N-N 0.4 E-E 1.1 very reasonable ,
but when the l-n are crossed over at the consumer unit . ok down stairs but the reading goes up to 16 ohms upstairs
but when l-e are crossed over at the consumer unit the last four sockets upstairs give no reading. at this point i am thinking the cpc is disconnected somewhere but i will test with a megger with the power on ,,for the Z
i do this and get good readings of 0.30 ohms at the four sockets previously Ze was 0.2 ohms

My thought was that a seperate or shared cpc had been run from the last four sockets on the radial going back to the consumer unit, need to go back and find out,

Can anyone understand this

 

[Lukethoma1985]

The cpc should be ok because end-ends are good. Cross polarity maybe? Run round with a sockets tester and make sure they all workbefore disconnecting anything

 

[Lukethoma1985]

Sorry ignore that, never read the title properly

 

[Lukethoma1985]

You could disconnect the ring circuit from the board, then test between one of the four sockets and one of the ring sockets for continuity