one ring main?

[bagnall1982]

noticed today when wiring in lighting circuit that i only have 1 ring main, is this a problem, is there a test i can do 2 check that the ring is ok, what values will i be looking for?

 

[Qedelec]

Its quite common.

Tests you can do:
1. Continuity of each conductor, Line, Neutral and CPC
2. Insulation tests between Line & CPC, Line & Neutral and Neutral & CPC
3. Connect in comming Line to outgoing CPC and vice versa, then measure between Line and CPC (R1 + R2) at each each socket (they should be very similar, higher at spurs).

That should be enough to be going on with.

 

[bagnall1982]

thanks for the reply qedelec, just another small question, what is total length of cable that should be used on one ring main as the house is quite having had a extension in the past?

thanks Nick

 

[GaryMo]

3. Connect in comming Line to outgoing CPC and vice versa, then measure between Line and CPC (R1 + R2) at each each socket (they should be very similar, higher at spurs).

That should be enough to be going on with.

Also do the same with Line and Neutral (R1+RN)

 

[bagnall1982]

will do this tomo, is there a range of values i should be looking for? the house is a 4 bedroom, granted it has a few small radial circuits but the ring must be quite large but has been like this since the previous owner had an extension 20 odd years ago im just worried that when i replace the old fuse wire cu and get it tested i will be told i need 2 ring mains because of the size of the current one?