earth loop reading

[IanMichael]

i have an earth loop reading of 3.24 ohms on a 32amp kitchen ring. i have tested insulation resisatance between p-n >130 and p-e >130. continuity resistaces are p-p 0.28 n-n 0.26 pe-pe 0.48. originally i had a damaged cable on this ring - so i replaced the cable, but still have a high earth loop.

any ideas?

how much effect does temperature have on earth loop readings? the consumer unit is very close to some flow and return heating pipes. can this effect the results that much?

 

[Taylortwocities]

Back to basics time.......

What is the supply type?
What is the Ze at the incoming supply?
What is the Zdb reading?

 

[IanMichael]

ze is 0.18

 

[IanMichael]

supply is tnc-s

 

[1john]

is it a proven ring, how exactly have you verified it is a ring final circuit? your reading should be about tenth of what you have.

 

[IanMichael]

done a final ring test, everything seams ok. all other ring mains in the house are fine.

how much of an effect will temperature have on an earth loop reading??

 

[sparkwright]

Are you testing Zs of this circuit by plugging into a socket?
Have you tried another socket?

 

[1john]

temp will have minimal effect, please explain how you have verified that this is a true ring final circuit.

 

[IanMichael]

tried with a plug tester and a lead tester. tested 8 sockets. all very high. at one point during the day i had a low zs of 0.44. then, when i did a final check of everything zs reading was very high again.

why i was wondering if the heating system can have an effect on earth loop readings?

 

[IanMichael]

l-n on oppostie cable to test for the ring. also stripped out each socket and did a continuity test between sockets to work out where the cables where going.

 

[1john]

need to do line to CPC to verify properly. you could have a run of spurs off of a ring main.

 

[sparkwright]

I hate asking this, but did you connect the earth wires up properly after the ring test?

 

[IanMichael]

2 spurs on the ring, how will that effect the ring readings???

 

[electronicsuk]

why i was wondering if the heating system can have an effect on earth loop readings?

Stop obsessing about the heating system. There is a fault somewhere, and it has nothing at all to do with the heating.

You say Zs readings were lower earlier in the day - is that also when you recorded your Ze?

 

[IanMichael]

yeah double checked all connections several times, completely baffled!