Very low CPC Readings

[chloebear]

Hi All,

Just been testing out some existing ring circuits in an existing building and I am when checking out Rn & R1 on the ring circuits all seems Ok with readings between 0.89 & 1.12 for 2.5mm singles, but when checking the cpc I am getting very low readings of between 0.01 & 0.03 for the same circuits as above????????? The majority of the installation is in steel conduit & box trunking, but as far as I can see the conduit system has not been used as the cpc.

Any thoughts??????????????????????????

 

[Sparky Ninja]

Here we go back to the old argument of installing a CPC in conduit. If the conduit installation is good there’s no need for a back up.

which is what my prior post was all about..

 

[Engineer54]

I would fully support that assessment, a good continuous, correctly installed conduit system, is a more than adequate means of CPC..

 

[IQ Electrical]

......and a knowledge of the type of installation to be tested/inspected.

Key words when undertaking periodic inspections.

 

[malcolmsanford]

Bit late to join the party, but you did test the right CPC's ? Very easy if a dedicated CPC is installed for someone before you to not connect in the same sequence of the earth bar as you think, and if you have several circuits coming into the board via one conduit it is easily done.

I would make 100% sure you have the right 2 CPCs for the ring final.

 

[zoomer]

if its in conduit you are also have fly leads on lighting circuits and other rings or radial circuits are you going to dissconect all of them as well because you will be on about 2p an hour

 

[GMES]

Seeing as the last reply to this thread was in 2011 I think it is safe to say the op will have resolved any problems he had, Thread closed.