What am I missing

[mikel]

Been doing a board change today, Loads of problems with the existing wiring but eventually getting there. (Had to split the ring main into two seperate radials, rewire burnt out shower terminals at both ends of circuit)

However can someone help me with a problem I've encountered.

Did r1+r2 for socket radial got 0.51 ohms

measured Ze (at new board) at 0.12 ohms

so I'm expecting a measured Zs of around 0.67 ohms.

and I get 1.20 ohms. Have checked all connections at board and they appea good, secure and no insulation trapped.

got similar results for all other circuits as well (as in discrepancy of around 0.5 to 0.7 ohms).

Any pointers to what I'm missing looking for the reason as to why the discrepancybad day explode

 

[Zeespark]

Loose connection at an accessory bud?

AndyGuinness

 

[mikel]

I thought of that but

1) would it not affect the r1+r2 readings

2) why would it affect all circuits

beginning to think it might be the meter but can't blame that till I've checked everything else

 

[Andy™]

new batteries req'd?

 

[NozSpark]

High resistace contact within MCB or RCD??

Do a Earth loop at incomming and outgoing side of RCD and outgoing side of MCB.. use same test method (No trip) for all tests!

 

[Voltimax]

Agree with Noz, If there's an RCD in place that will be why you're getting a high Zs. I've yet to find one yet that doesn't give a high reading.