ZS on final sub circuit

[EddieB]

Lads
Have measured R1 + R2 and get a total of .45 ohms, when I test the ring with my tester I get 2.1ohms, the unit was calibrated last week, any ideas?

 

[telectrix]

what's the Ze? and if it's a sub main, the Zdb?

 

[Amp David]

Have you terminated the CPCs back without trapping any sleeving under the screw.

 

[mattmoo1974]

You using a "Socket and see" and probes? Or the kettle lead?

 

[Sintra]

What are yor r1, rn & r2 readings on the ring? Ze or Zdb readings? Is this circuit protected by a RCD or RCBO?

 

[EddieB]

Ze is .27, the sleeving is not trapped, the circuit is RCd protected, not that makes any difference to the reading at the sockets, the test lead is a kettle type.

 

[Sintra]

You could find that it is the RCD that has the high impedance. Try a loop impedance test both sides of the rcd and see if it differs.

 

[EddieB]

Sintra, I'll give it a go thanks for the advice

 

[Deleted member 9648]

The current crop of 2 lead no trip meters give totally unreliable readings as well.....worth bearing in mind if you are testing with one of those.