Green Neutral Insulation

[Knobhead]

That the cable has a maximun rating of 600V between Live/Earth and 1000v between Live conductors. What's your point? No need for sarcasm.

OK so far so good.

What is the minimum test voltage to prove a cable?

Don't look in BS7671

 

[Knobhead]

BTW I’ve been drinking Melomel cider all afternoon.

 

[Richard Burns]

The higher the voltage you test at the more likely it is that small imperfections would show up as a lower IR reading and give you an indication of an incipient fault earlier than a lower test voltage.

If blue insulation is over heated then it can cause changes in the colours used to impregnate the insulation as chemical reactions including oxidation will occur much more rapidly, reduction in the number of double and triple bonds in a coloured organic material can stop the material being coloured. If the blue is made up of a mixture that includes green to get the shading right and the blue colour is decolourised then green will remain.

 

[Electric Yo]

OK so far so good.

What is the minimum test voltage to prove a cable?

Don't look in BS7671

Well for a 230V circuit, 500V.

Ol Bristolian is my favourite =)

 

[Silly Sausage]

BTW I’ve been drinking Melomel cider all afternoon.

Aaahhh...that reminds me, 3 days of free real cider coming up soon!
I work the Cider Bar at a Beerfest every year.

 

[Electric Yo]

The higher the voltage you test at the more likely it is that small imperfections would show up as a lower IR reading and give you an indication of an incipient fault earlier than a lower test voltage.

If blue insulation is over heated then it can cause changes in the colours used to impregnate the insulation as chemical reactions including oxidation will occur much more rapidly, reduction in the number of double and triple bonds in a coloured organic material can stop the material being coloured. If the blue is made up of a mixture that includes green to get the shading right and the blue colour is decolourised then green will remain.

Thanks. Yeah that seems logical to me, but I can only see use for it in special circumstances. As I see it the lower the test voltage you can use to confidently prove a cable the better. As we all know the higher the voltage used the more dangerous it can be if something should go wrong.

However this green discolouration seems to allude me.

 

[Knobhead]

Aaahhh...that reminds me, 3 days of free real cider coming up soon!
I work the Cider Bar at a Beerfest every year.

This one is called Scrimpy 6.4%. The honey leaves a nice after taste. Well worth looking for. £3 a pint in my local.

BTW, I’ve taken 2.5 T+E up to 14.5KV before it failed.

 

[shanky887614]

This one is called Scrimpy 6.4%. The honey leaves a nice after taste. Well worth looking for. £3 a pint in my local.

BTW, I’ve taken 2.5 T+E up to 14.5KV before it failed.

have you tried raging bitch tony? now that is a strong % ale

 

[jaypp]

Saw low smoke that had changed colour over a couple of weeks in a warm, sunny location. Outer sheath was stripped a little, circuit not energised, and noticed conductors had same 'base colour' insulation - just outer for brown/blue, brown/black/grey.

 

[Guest111]

testing a cable with a 1000v test is pretty common for an experienced spark lets be honest suppose on a shower circuit you have some form of problem with the cable that MAY only show up when there is steam present,now without the steam this may not show up on a 500v test,however it has more chance of showing up on a 1000v test.Regarding risks if things go wrong,if the cable is disconnected at both ends the only risk is the operator receiving a shock and given that the test current is only a few milliamps then nothing is going to happen.Back in the day we used to shock each other with meggers so you knew what it felt like,that's probably banned now under some obscure EU law as a cruel and unusual punishment.

 

[DPG]

Was the installation done by the same spark who did the work you saw last week which had similar issues, ie. termination problems/cables overheating? Daz