R1 R2 Chestnut time again

[the pict]

We all know how to and why we get the 1/4 value, but to what, if anything do we add to that figure and into what box on the cert does it go, depends on who you ask/assessor is apparently,

 

[newfutile]

If you’re talking about ring circuits ? then you need to get your capitals correct
r1 rn and r2 are for ring final circuits and are different from R1 and R2 which is the resistance or impedance of the line and cpc

 

[loz2754]

The r1+ r2/4 figure is really only used as a comparison or check to see if the actual R1+R2 readings at each point on the ring are as you expect them to be.
The only figure you record on the schedule of test results is the highest measured R1+R2 value.
It doesn't depend on who you ask. It's plainly written down in GN3 and other readily available publications.

 

[Risteard]

We all know how to and why we get the 1/4 value, but to what, if anything do we add to that figure and into what box on the cert does it go, depends on who you ask/assessor is apparently,

If you add the (R1+R2) to the Zdb then this will give you an indication as to the expected maximum Zs for the ring final circuit.

 

[the pict]

If you add the (R1+R2) to the Zdb then this will give you an indication as to the expected maximum Zs for the ring final circuit.

The r1+ r2/4 figure is really only used as a comparison or check to see if the actual R1+R2 readings at each point on the ring are as you expect them to be.
The only figure you record on the schedule of test results is the highest measured R1+R2 value.
It doesn't depend on who you ask. It's plainly written down in GN3 and other readily available publications.

OK lets take some actual numbers, Ze or Zdb .22, on the ring Live .45. CPC .76 So 1.21 / 4 = .30 That figure is only used to check around the RFC for higher than expected readings It goes nowhere on the cert, what does go on the cert is the sum of ZE & R1+R2 which is 1.43 which is Max measured ZS only its not, its the
sum of the readings, to get a measured ZS its a live test done at a socket as that is the only real result . However according to other informed sources the Box asking for max measured ZS should be the 1/4 value plus Zdb which is .52 in the above example not the 1.43 using ZS = ZE +R1+R2 that said I will stick to the way I was trained ZS is Ze +R1 +R2 there is no other answer

 

[davesparks]

However according to other informed sources the Box asking for max measured ZS should be the 1/4 value plus Zdb which is .52 in the above example not the 1.43 using ZS = ZE +R1+R2 that said I will stick to the way I was trained ZS is Ze +R1 +R2 there is no other answer

No, the max measured is the maximum value which has been measured.
A measured value is not calculated, it is measured.

 

[Electro-tech]

If you have measured all tests correctly on a ring final circuit & checked the r1 + r2 /4, you will have all the necessary check sums & measured results ( Ze, Zs Zdb) to fill out the cert. So whats the problem ! Maybe( R ) Stands for Radial !

 

[the pict]

No, the max measured is the maximum value which has been measured.
A measured value is not calculated, it is measured.

I understand but can you explain this, its from an example eicr in a well know textbook R1 .46 R2 .76 r1+r2 = 0.08 ? with a max measured Zs of .37

 

[the pict]

The r1+ r2/4 figure is really only used as a comparison or check to see if the actual R1+R2 readings at each point on the ring are as you expect them to be.
The only figure you record on the schedule of test results is the highest measured R1+R2 value.
It doesn't depend on who you ask. It's plainly written down in GN3 and other readily available publications.

It's plainly written down in GN3 and other readily available publications. can you tell me the page

 

[nicebutdim]

Section 2.6.5 of current edition GN3.