Circuit Impedance

[desertbootz]

Taking over a building and starting to get PIR's for handover. They are NICEIC styley and under Circuit Impedence they have three columns for Ring and two for 'All Circuits'. The tester has filled in all columns for every cct but they don't make much sense, eg, 4mm line and cpc, R1=0.39, Rn=0.42, r2=0.50 which seems okay (allowing for meter error etc.) but then the 'All Circuits' column shows; R1+R2=0.14, R2=0.50.

How do you get an R1+R2 lower than the values of R1 and R2? Is he bluffing it or am I being a mong?

All advice/abuse received in the manner it's meant :O)

 

[old dog]

hi i get r1+r2=0.22
the first readings he gives are r1 end to end the same for r2 and rn
with the r1 and r2 cross linked the reading at the sockets should be approx 1/4
r1+r2/4

 

[desertbootz]

Maybe I wasn't clear. I understand R1+R2 on the ring is measuring the conductors in parallel hence the lower reading but how/why would these readings be filled in for lights?

 

[ezzzekiel]

if you mean what i think you mean, then he has carried out a ring final cont test on a radial circuit - which is incorrect

 

[old dog]

hi can you show us the readings he has put down and what ciciuts
they are for ?

 

[Des 56]

We should not assume the lights are radial
There are occasions for example, volt drop problems, where ring circuits for lights are installed
What does it say in the column for number of conductors for the circuit
(if the nic form has this column)