Stupid questions time.

[SparkyJoe]

Right, here we go.

Im testing an old skool (Well before my time) ring main. L&N in a ring and the E off the containment and im getting some bloody horrible insulation results, I was thinking it was down to a load I could't find, but its also down to earth.

So ive got

L - N 3.55 ohms
L - E 3.46 ohms

(This is on continuity not ins test)

Now unless im being really thick, (which as it happens I think I am) if you had a resistance of 3.46ohms @ 240volts you should have 69amps? ie, it would have taken the mcb out?

any ideas? or have i just missed something

Ive got a Zs of 0.34 so i guess that the earths not bad.

 

[malcolmsanford]

Right, here we go.

Im testing an old skool (Well before my time) ring main. L&N in a ring and the E off the containment and im getting some bloody horrible insulation results, I was thinking it was down to a load I could't find, but its also down to earth.

So ive got

L - N 3.55 ohms
L - E 3.46 ohms

(This is on continuity not ins test)

Now unless im being really thick, (which as it happens I think I am) if you had a resistance of 3.46ohms @ 240volts you should have 69amps? ie, it would have taken the mcb out?

any ideas? or have i just missed something

Ive got a Zs of 0.34 so i guess that the earths not bad.

What is your r1 rn giving you?

I would say you may have a polarity cross over somewhere, assuming there is no RCD on the ring then it would only get picked up on your testing

 

[SparkyJoe]

R1 0.74
Rn 0.64

I stuck a clamp meter on it at the time, with everything (i could find) unplugged i was getting 0.1. If it had just been L-N id have just put it down to unknown load, but i dont get what could give me L - E? Transformer or something?!