2391 practical

[andy1984]

hi

on the 2391 practical when doind the first test, continuity of circuit protective conductors can i take out the phase conductor for the circuit under test and put it into the earth bar thus getting the R1+R2 aswell to save time?

main question though is do i have to disconnect any other earths from the main earth terminal before doing this?

such as the main earth or supp bonding? bit confused on the parralel paths subject.

at what point do i disconnect earths and for what earths and for what reason?

cheers guys.

 

[cozycats]

READ GN3 and do all tests as described!!!!

 

[The Jeep]

Parallel paths only exist where they make a complete circuit at the point of measurement. If you test, say, between the disconnected earth of a lighting circuit and the earth bar in the CU where the lighting circuit earth is connected, even with your main earth bonding and other circuits' earths connected to the bar, you are only measuring the resistance of the lighting circuit earth between the CU and the other disconnected end.

If you hadn't disconnected at least one of the ends, then you would be getting into parallel path territory. Just remember that the test current has to flow in a complete loop. Any incomplete loops will have no effect on the measurement.

 

[comms]

Or put a link in between the met and the phase conductor (mcb) of the circuit your wanting to get the R1+R2 / continuity of cpc from, and test at furthest point of circuit, then just move the link on to the phase conductor of the next circuit your wanting to test cpc continuity of, leaving the other end of link connected to the met.
Don't forget to remove the link when you've completed cont testing.
But has already said take a look at GN3 or osg.