R1 + R2 does not equal (R1+R2) in example in On Site Guide.

[HappyHippyDad]

I have always been a bit confused about boxes 10,12 and 13 in the example of a completed 'Form 4 - schedule of test results'.

I understand why the value we get for R1+R2 (when measured at a socket) is a quarter of the end to end resistances, but why on the form is this not more clear?

Box 10 (R1) and Box 11 (R2) do not equal Box 13 (R1 + R2). Again I understand why, but it just seems wrong to have a box for R1 and a box for R2 but adding them together is not R1+R2.

Its annoying :cuss:

 

[Jay Sparks]

That's because its not R1... Its r1!! And when you measure a radial, you are measuring R1 + R2. So in affect your not adding r1 to r2, although we do this for a ring to see if our readings are correct.

 

[Jdsparky]

Note the use of upper and lower case letters then you will understand better

 

[Geoffsd]

On my forms only 'R' (upper case) values are recorded.

In this case R1 and R2 should add up to R1+R2.

 

[telectrix]

surely your forms have a column for r1+r2 for RFCs?

 

[KAS1]

You're right even in GN3 'Form 4 - schedule of test results' note13 refers to Ring (R1+R2) and not r1+r2 bloody IET lol

 

[Geoffsd]

No. They are Castline Formfill (free).

Do you think it's a mistake?
Doesn't really matter, does it?

You either have to multiply mine by 4 to get 'r' or divide yours by 4 to get 'R'.

 

[KAS1]

should be another column IMO more books=more cash

 

[Geoffsd]

You're right even in GN3 'Form 4 - schedule of test results' note13 refers to Ring (R1+R2) and not r1+r2 bloody IET lol

No that would be correct.

We are refering to the separate columns for L, N & cpc end to end.

 

[jamesBoater]

Page 169 Green OSG, nature of supply parameters, 150Hz !

 

[KAS1]

Perhaps I'm reading it wrong but that's not what GN3 is showing on page 98,99 and 100 or is it

No that would be correct.

We are refering to the separate columns for L, N & cpc end to end.

 

[KAS1]

He said col 13 ????

 

[KAS1]

Where did he mention the N?

 

[KAS1]

I agree............................................................

I have always been a bit confused about boxes 10,12 and 13 in the example of a completed 'Form 4 - schedule of test results'.

I understand why the value we get for R1+R2 (when measured at a socket) is a quarter of the end to end resistances, but why on the form is this not more clear?

Box 10 (R1) and Box 11 (R2) do not equal Box 13 (R1 + R2). Again I understand why, but it just seems wrong to have a box for R1 and a box for R2 but adding them together is not R1+R2.

Its annoying :cuss:

 

[Geoffsd]

He said col 13 ????

Yes but col. 13 IS R1+R2.

He was wondering why cols. 10 (r1) and 12 (r2) do not add up to col 13 because he mistakenly called them R1 and R2.

As I wrote, mine do as they ARE R1 and R2 not r1 and r2.

Col. 11 (rn or Rn) is incidental but the same.

Is that clear?

 

[Flanders]

r is for ring
R is for resistance
R1 + R2 is the resistance of the earth and line of the circuit connected together

but if you do add r1 and r2 together and divide by 4 you should get R1 + R2 in theory

Due to parellel Earths though you may not get a text book reading

As stated R and r are completely diferent

 

[KAS1]

clear to me, but you couldn't of read GB£ page 100 note 13 Is that clear?

Yes but col. 13 IS R1+R2.

He was wondering why cols. 10 (r1) and 12 (r2) do not add up to col 13 because he mistakenly called them R1 and R2.

As I wrote, mine do as they ARE R1 and R2 not r1 and r2.

Col. 11 (rn or Rn) is incidental but the same.

Is that clear?

 

[Geoffsd]

clear to me, but you couldn't of read GB£ page 100 note 13 Is that clear?

I presume you mean "I can't have read GN3 page 100 note 13".

What does it say?

 

[KAS1]

Yes sorry, trying to do more than 1 thing at a time...................I'll let you have a read and see what you read into it lol

I presume you mean "I can't have read GN3 page 100 note 13".

What does it say?

 

[Geoffsd]

I have found it in the BGB.

You mean measuring from a spur would make R1+R2 more than (r1+r2)/4.

That would be true but I still think you have missed the point of the OP and my comments.

 

[Dubbo]

I have always been a bit confused about boxes 10,12 and 13 in the example of a completed 'Form 4 - schedule of test results'.

I understand why the value we get for R1+R2 (when measured at a socket) is a quarter of the end to end resistances, but why on the form is this not more clear?

Box 10 (R1) and Box 11 (R2) do not equal Box 13 (R1 + R2). Again I understand why, but it just seems wrong to have a box for R1 and a box for R2 but adding them together is not R1+R2.

Its annoying :cuss:

The form is correct as boxes 10,11 and 12 are asking for the end to end resistance for r1 , rn and r2 , these are all end to end resistances as in step 1 of the ring final circuit test to check that they are substantially the same , the true R1 + R2 of the circuit is established in step 3 by cross connecting R1 and R2 and measuring at each socket outlet this goes in box 13 . If you add up box 10 and 12 and divide by 4 this cross references your R1 and R2 .

 

[varilite]

It's really quite simple, if doing an EICR the installation has power so only need to do end to end to make sure it's a ring then do. ZS at each socket. If no power then you have to do R1+R2 and work out ZS by adding it to ZE.