continuity strange results!

[scotteng]

help!! just testing an old lighting circuit, and the results for the continuity tests are showing over 110 ohms....very high!! although zs tests are showing good results at 1.59...
any suggestions to why im getting these conflicting results?? the test is part of a peridoic, zs results are a pass, but R1+R2 results show there is a problem somewhere. the circuit is protected by rcd, an all other tests pass, just the R1+R2.
would you class the results as unsatisfactory? or satisfactory with a requires further investigation!
any help would be appreciated.
oh the dodgy results are only on part of the circuit!

 

[ricicle]

What type of wiring system is it on ?
Sounds like a broken/high resistance earth but parallel paths keeping the Zs down.

Unsatisfactory, there is no earth continuity. An RCD is not a substitute for bad earthing !

 

[scotteng]

resistance/broken earth, what would cause this and how would i find the fault?

the wiring is pvc, twin and earth, lighting radial circuit

 

[ricicle]

Corroded/poor or broken/non existent connection. Trace the circuit up to the point that you no longer measure a satisfactory R1+R2 or R2 figure.
Hopefully you may find it at a light or switch, but there may be a JB lurking somewhere!

 

[Taylortwocities]

Aye R2 test with a long wander lead is the best way.

 

[VanSolo]

and remember.
Visual inspection is a very important part of a p.I r.