R1 + RN on Ring final circuits

[Jim2287]

I know how to carry out the test, but i am not sure i understand the reason for carrying it out...

some ideas of mine are ...

R1+RN could be used to calculate PSCC ?

A high R1+RN would signify spurs/alterations to the circuit ?

"rn ring continuity" doesnt actually confirm there is a neutral at the socket (as the neutrals could be twisted together and fallen out of the back of the socket) and so R1+RN test is carried out ?


Are these ideas right and are there any other reasons for carrying out this test ?



Thanks
Jim

 

[Adam_151]

You are checking the ring for any undesireable forms such as bridges, chains of spurs etc,

Every outlet on the ring should give you the same reading when tested between phase and neutral, when you have got neutral 1 connected to phase 2, and neutral 2 connected to phase one back at the board, spurs will be a bit higher

 

[dingbat]

You cross-connect phase and neutral when checking a ring because these conductors are the same size; variations in readings due to different sizes (as in phase/CPC) are then ruled out.

This test is carried out purely to verify that you have a simple ring circuit, or identify spurs.

Of course, in an older installation, readings may be affected by poor contact resistance between test plug and terminations, for a number of reasons. Because of this it can be nigh-on impossible to verify anything with any certainty in an older ring circuit without dismantling... a damned good reason to do away with them altogether!

 

[festa]

a damned good reason to do away with them altogether!

I totally agree.... and seeming as we are coming inline with European standards(and we are the only country to use rings*) do you see ring final circuits being phased out?

*cannot be 100% sure we are the ONLY country .