Continuity of neutral conductor

[seftonbarn]

This won't be the first daft posting of mine, but apparently once you get up to 20 postings you get additional privileges. So please treat me with contempt.

When testing a radial circuit you establish continuity of the Line and earth when you measure R1+R2. What test ensures continuity of the neutral conductor?

I brace myself for an answer that is going to confirm my question is a daft one.

 

[jdd]

rN+r2, this should be the same as r1r2. Also a good way to prove polarity.

 

[seftonbarn]

Whooops didn't know that was needed. Is that in the OSG?

 

[jdd]

Haven't looked TBH, an effective way or verifying polarity though.

 

[habitual]

You have in fact answered your own question.
If you do a temp link from earth to line and test along the length of circuit you have established continuity at each outlet, this will establish correct polarity of earth and line, following this we can assume that neutral is also established but there is no reason for you not to test that as well. Its not a daft question by the way. It shows that you are thinking about how you would confirm it is indeed verified.

 

[Silly Sausage]

The sockets after the neutral break wouldn't work!

 

[JUD]

R1+R2 is just 1 way to prove the continuity of the cpc, not the line. R2 only (using a wander lead) is equally acceptable.

That being said, if you really need to prove the continuity of the neutral I would say R1+Rn would be the best option. This way you can verify voltage drop at the same time.

Polarity can be proved while you're measuring R1+R2.

 

[habitual]

Jud have we been drinking the vino tonight ?
contradiction in your post I am assuming was because of the fine state you may be in.

 

[jdd]

I don't think polarity can be proved on with r1+r2 on its own.

 

[JUD]

Jud have we been drinking the vino tonight ?
contradiction in your post I am assuming was because of the fine state you may be in.

Please enlighten me

 

[seftonbarn]

R1+R2 is just 1 way to prove the continuity of the cpc, not the line. R2 only (using a wander lead) is equally acceptable.

That being said, if you really need to prove the continuity of the neutral I would say R1+Rn would be the best option. This way you can verify voltage drop at the same time.

Polarity can be proved while you're measuring R1+R2.

Thanks Jud. Understand your bit about R1+Rn. Please explain how this verifies votage drop. too tired to think through the logic.

 

[jdd]

R1+RN x 1.2 (worst case scenario) x Ib = Volt drop

 

[JUD]

Thanks Jud. Understand your bit about R1+Rn. Please explain how this verifies votage drop. too tired to think through the logic.

Using the resistance of R1+Rn you can work out the VD of the circuit.

VD = (R1+Rn) x Cr x Ib

Cr = Correction factor for conductor operating temperature
Ib = Design Current

 

[JUD]

jdd beat me to it

 

[jdd]

Sorry mate. :>