Calculating Zs

[sparx northeast]

I need to calculate the Zs for a ring main that uses the metal conduit as CPC. I know that Zs = Ze + R1R2 but I only have an R2 reading as there is no wired CPC. Anyone got a clue?

 

[VoltzElectrical]

I do. All he did was carry out an inspection/ test. In your post you mentioned 'install'.

DNO fault found, DNO rectified, OP expected to go back and re-test free-of charge?

Did I miss something? I love the taste of humble pie!

 

[MDJ]

I love the taste of humble pie!

me too, it wasn't in the op, it was about 5 or 6 posts after it, and in anycase still not good enough, but yes humble pie.

 

[GLENNSPARK]

Way too harsh and well off the mark there based on my reading of the OP.

Sorry if I'm wrong.

Sounds like you should spend less time hanging out with Glenn!

mike`s right....just reading through this....

so if he only has R2....wheres his calculated Zs coming from?..

further more just using a nominal Ze doesn`t cut it for me...A nominal is fine...for the design room..

but when out there on the flukes its actual measured values....

its a bit like them on the old 2391 that when asked to apply the .8 correction factor to a Zs...then went forth to apply it to the actual measured value...

bloody useless....

 

[Engineer54]

I think that i can honestly say i've Never recorded calculated Zs values on any official report/test sheet. It has and always will be the measured values that are recorded...

And i don't give a monkey's thought, what colleges are teaching, what it say's in BS 7671, or what anyone else has to say. Measured values are proven values, not hypothetical calculated values....

 

[GLENNSPARK]

I think that i can honestly say i've Never recorded calculated Zs values on any official report/test sheet. It has and always will be the measured values that are recorded...

And i don't give a monkey's thought, what colleges are teaching, what it say's in BS 7671, or what anyone else has to say. Measured values are proven values, not hypothetical calculated values....

yep...

sense at last...