How to find R1 and R2 separately

[helio007]

hi all just got a Q regarding how to find R1 then second Q how to find R2 what i did so far was mutiplying each answer for1.67 so I could get the answer for R2 is there a easy way to find R1 without kinda guessing TIA .

 

[westward10]

Do you have Guidance Note 3. You can't guess the answer.

 

[loz2754]

The 1.67 multiplier only works for 2.5 line conductor with 1.5 protective conductor. The cable specified is 4mm line conductor with a 1.5 protective conductor. You should be able to work out what multiplier to use in this case.

How to find the r1 value? By using the on-site guide tables.

 

[helio007]

Do you have Guidance Note 3. You can't guess the answer.

Yes I do , which done 16.71x58/1000=0.97

Do you have Guidance Note 3. You can't guess the answer.

 

[helio007]

The 1.67 multiplier only works for 2.5 line conductor with 1.5 protective conductor. The cable specified is 4mm line conductor with a 1.5 protective conductor. You should be able to work out what multiplier to use in this case.

How to find the r1 value? By using the on-site guide tables.

4mm L 1.5cpc 16.71

 

[westward10]

Okay so you have the Table. From this you can calculate r1 and r2 separately. What you have done from your figure and looking at the Table is put r1 and r2 in parallel.
Just to add continuity for a ring final is lower case so r1 not R2.

 

[westward10]

4mm L 1.5cpc 16.71

No split them, look at separate values for 4.0 and 1.5.

 

[helio007]

No split them, look at separate values for 4.0 and 1.5.

4mm 4.61 sorry if I'm not that knowledgeable but I can't find on the table cpc value on its own .

 

[westward10]

The Table is a bit misleading. A 1.5 conductor will have the same resistance whether it is r1 or r2. Use the line column for the 1.5 cpc.

 

[westward10]

Alternatively take the 16.71 for 4.0/1.5 and deduct 4.61 for the 4.0 and this will give you 1.5. Same result either way.

 

[helio007]

Alternatively take the 16.71 for 4.0/1.5 and deduct 4.61 for the 4.0 and this will give you 1.5. Same result either way.

Will try it now . Thanks mate much appreciated ur help

 

[westward10]

Will try it now . Thanks mate much appreciated ur help

No worries.