Insulation Resistance

[sparkzalot]

So i have db1 in 1 block of flats for communial lights etc, feeding db2 via a swa feed underground. Ir at db1 to test every circuit and submains 0.01Mohms. (N+L together to earth)
Switch db2 off. All clear. Db2 also all clear when testing ir when investigating further.
Any suggestions??

 

[Dave OCD]

An item of equipment must still be connected [Fed from DB2] giving the low resistance between L & N ?

 

[Hellmooth]

An item of equipment must still be connected [Fed from DB2] giving the low resistance between L & N ?

He has L & N together? And DB2 is clear when testing on its own?

 

[sparkzalot]

No because db2 was all clear when testing that separately

 

[Richard Burns]

DB2 neutral must be fed from the supply directly rather than from the DB1 Neutral bar. Perhaps.

 

[sparkzalot]

No 1 of the cores was definitely connected to the neutral bus bar

 

[Andy78]

What further IR testing did you carry out after these results ?

 

[R G]

Isolate every circuit completely at both boards and make sure all equipment is unplugged or fully isolated and test each section in turn , simple ....

 

[sparkzalot]

No 1 of the cores was definitely connected to the neutral bus bar

 

[sparkzalot]

What i did. All clear. Was down testing the whole installation. Im thinking possibly the 2 rcds. Its pickled me any how...