Impedance Zs

[robertoj]

hi everyone I have a question: Water heater 3kw the length of the circuit is 28m , the line and cpc 2.5mm2 How determine the expected Zs? I'm looking for in On-Side Guide but I do not know..... any suggestions please Thanks

 

[Simonslimline]

Look for resistances of 2.5mm2 line and 2.5mm2 CPC. is this unit 307?

its near the back of the OSG

Don't forget to add the Ze value from the question to make the Zs

 

[Bobster]

Zs=Ze+(R1+R2)

This is very simple

 

[robertoj]

ok I found it thanks

 

[Engineer54]

I'm wondering why you need the OSG to work out the calculated Zs value of a circuit?? This is, or damn well should be basic knowledge to you!!!

 

[davesparks]

You've got to get the data from somewhere haven't you? The guy is in training, you can't expect him to have learned the resistance of conductors off by heart!

 

[Engineer54]

You've got to get the data from somewhere haven't you? The guy is in training, you can't expect him to have learned the resistance of conductors off by heart!

If that's the case, why isn't his user name in purple or whatever it is??

 

[nickblake]

Robs given you the Zs = Ze plus r1 r2 , if you do your r1 r2 ,switch supply off disconnect the main earth and take your Ze from the main earth block if the cut out if it has one or main earth cable removed from earth at board and across live and neutral , once ze has been done then reconnect your earth add the Ze to the r1r2 and that will be the calculated Zs you can the do the live Zs the result could be different due to parallel earth paths etc

 

[Sintra]

If that's the case, why isn't his user name in purple or whatever it is??

Because according to his profile he's an electrician.

 

[Engineer54]

Because according to his profile he's an electrician.

Then i rest my case!! lol!!

 

[davesparks]

Whoops, I saw the next post mentioning NVQ topic numbers and made an assumption!
Everybodies name is red when viewed through tapatalk.

 

[Simonslimline]

The question posted is a homework question from unit 307 or 308. i did the same question a couple of weeks ago.