Very high Zs reading

[mspms]

Good evening all. I wonder if anyone could give me a steer as to why I am getting very high Zs readings. I have been testin a circuit that has a R1+R2 of 0.23 ohms but I seem to be getting Zs reading on L-E of + 40ohms. L-N is coming in at 0.2ohms. The incoming fuse is a 63amp BS1361 an RCD main switch protecting all circuits. All other tests are fine. I am wondering whether it could be my meter not reading correctly on the Zs test. Any ideas?

Thanks all.

 

[mspms]

Brand new RCD main switch today. I even tried with the old 2 pole main switch. still high.

 

[Rauer]

What tester is it?

 

[mspms]

Leads have been zeroed.

 

[stef]

Batteries going down? Bad contacts on the three pin plug? Dodgy terminations, any load on the circuit? (mainly an inductive might cause a false reading) What make of RCD is it?

 

[mspms]

Just a quick note I have just tried a socket in my place and I;m getting 48.1ohms with a pefc of ony 4.78amps.

 

[stef]

That rules the RCD and the circuit out.

 

[Richard Burns]

Do check your settings on the meter and the battery level just in case.
Then try testing in your house as close to the origin as possible, without any switches, just the supply and see what reading you get, if it is still +40ohms then sounds like a leads or meter problem.
What reading do you get on testing resistance on the leads?

 

[stef]

Check the fuse and the contacts of the three pin plug.

 

[Rauer]

Try it with your probe leads and not your plug top lead

 

[stef]

Or test with a known reistance...

 

[mspms]

I have spent the last 2 days going through the entire house checking and testing and putting right some very sorry wiring expecially on the R2 side of things. I am happy with all of the wiring and the results that I have had on the continuity and resistance side of things. it is this very high Zs I can't seem to fathom out. The RCD is a Hager.

 

[mspms]

I'm getting 0.6 on leads.

 

[stef]

Switch off your meter, remove all batteries, wait then put them back and try again. I am running out of ideas.

 

[Rauer]

Plug top lead sound a bit suspect to
Me at the mo

 

[mspms]

That sould be 0.06.