No seperate earth In ring

[Delboy247]

Hi come across a ring wired in 2.5 singles in metal conduit the problem is there is no seperate earth, there is a fly lead how would I do the
R2 test
R1+R2
What would I write on the report.
The installation is over 20 years old no rcd protection.
Good Zs Reading

 

[Sintra]

Connect one terminal of the continuity tester to the installation main earthing terminal, and with a test lead from the other terminal make contact with the conduit at various points on the circuit, e.g. luminaires, switches, spur outlets, etc.

This resistance R2 is required to be recorded on the Schedule of Test Results.

1. Inspect the enclosure along its length for soundness of construction

2. Perform the standard ohmmeter test using the appropriate test method described
above.

 

[Delboy247]

When you say test lead use a wonder lead around the building cheers sin.

 

[telectrix]

Connect one terminal of the continuity tester to the installation main earthing terminal, and with a test lead from the other terminal make contact with the conduit at various points on the circuit, e.g. luminaires, switches, spur outlets, etc.

This resistance R2 is required to be recorded on the Schedule of Test Results.

1. Inspect the enclosure along its length for soundness of construction

2. Perform the standard ohmmeter test using the appropriate test method described
above.

is it necessary to measure R2 on it's own. could not R1+R2 at the furthest point be entered on the test sheet?

 

[Sintra]

Not necessary but as it is a ring i personally find it easier to measure the R2 of the conduit and record that value.

 

[telectrix]

agreed. as alexander the meerkat says " simple"

 

[WayneL]

This scenario has got me thinking - and it's beginning to annoy me coz I'm having trouble working it out.

If it's a 'Ring Final' - what happens with regards the 3-stage 'Ring Final' tests?

Let's say there are no previous test sheets so you can't get away with just proving CPC continuity, you have to do the full set of tests.

Or better still, lets say you've installed it and now have to test it.

How do you go about it? How do you cross connect when you have 'L' & 'N' running as normal from socket to socket and back again, but your conduit(in effect a radial) is your CPC?

Am I missing the obvious? - or would you just not install a 'Ring Final' without seperate CPCs in the first place.
Any 'Ring Finals' in conduit that I have tested always had a seperate CPC running in them with flyleads off to the backboxes.

 

[andekoch]

make sure to fix a not to the CU letting others know that the conduit is the cpc and must remain continuous. technically you could disconnect the conduit from the CU and that way you have your cpc 'ring' to do the full range of ring tests with.