R1 + R2 of ring circuit

[haptism]

Hi for a ring circuit, is there any need to measure and enter R1 + R2 values on a schedule of results ? Because an r2 value is already measured (together with r1 and rn). If I needed a ring R1 + R2 value to calculate ZS (although i would find ZS with a socket tester so really no need; but if I did) would i find it using the formula ZS = (r1 + r2)/4 ? Thanks all

 

[Hellmooth]

Verification that it is a ring circuit would be a good reason.

 

[jackhammerJIM]

Verification that it is a ring circuit would be a good reason.

That would be r1 rn r2 . not R1 + R2

R1 + R2 IS required to confirm polarity

 

[Wilko]

Yep, values from testing are needed for your test schedule for both r and R. GN3 has method laid out in section 2.2.6.

 

[haptism]

I dont have GN3 yet unfortunately. On the test schedule (IEE model form) there is a column for r1, r2, and rn values, so its obviously a ring im testing. The next column along asks for either R1 + R2, or R2; R2 is long lead method which would give exactly the same value as r2. So with that in mind whats the point of recording an R1 + R2, or R2 value if you have already measured r2 ?? Which my question is, do I need to enter an R1 + R2 value if i already have r2 ?? If you get what I mean that would be great

 

[jackhammerJIM]

yes you need R1 +R2 to confirm polarity

 

[telectrix]

R2 reading wound not be same as r2.

 

[Wilko]

Def recommend GN3 ... I do tests and enter values for r1, rn, r2 and (R1+R2). Then I compare (r1+r2) to (R1+R2), looking for the magic 4 factor if I've built it right

 

[kropaske]

I dont have GN3 yet unfortunately. On the test schedule (IEE model form) there is a column for r1, r2, and rn values, so its obviously a ring im testing. The next column along asks for either R1 + R2, or R2; R2 is long lead method which would give exactly the same value as r2. So with that in mind whats the point of recording an R1 + R2, or R2 value if you have already measured r2 ?? Which my question is, do I need to enter an R1 + R2 value if i already have r2 ?? If you get what I mean that would be great

With r1 r2 rn you confirm that it is RFC by doing R1+R2 you verifying that cpc is actually connected to the socket and as jackhammer said verifying polarity

 

[sparksburnout]

Def recommend GN3 ... I do r1, rn, r2 and (R1+R2).

Or an I&T course? Like a sparks....

 

[Risteard]

R2 is long lead method which would give exactly the same value as r2.

It certainly shouldn't if done correctly! In fact it should be a quarter of the r2 value if there are no spurs. But given that the test for the (R1+R2) value is required as part of the ring final circuit continuity tests I see no merit in opting for R2 over (R1+R2) presuming that we are discussing initial verification here.

 

[haptism]

Okay, so in step 3 of the ring final test, when you cross connect L + E, the highest result is your R1 +R2. Having a brain drain today, quickly why would R2 differ from r2 ?

 

[kropaske]

Okay, so in step 3 of the ring final test, when you cross connect L + E, the highest result is your R1 +R2

correct

r2 is end to end
R2 is when joined together

 

[haptism]

Thanks all, and thanks for your patience and goodwill,

 

[Risteard]

why would R2 differ from r2 ?

Because with it all connected in parallel it will be double the cross-sectional area and half of the length.