Bridging between Phase and CPC etc when testing

[thomo27]

A'noon ,
my post is to do with testing , I purchased an ins/continuity tester to familiarise myself with some testing before my assessments , the book I bought (Anthony Harland) shows a black wire bridging the phase and cpc together on a lighting circuit when checking CPC continuity , my question is: Am I able to use any certain cable colour i.e. Brown a bit of old Red , Blue cable as my link ? Is the cable size an issue as Im thinking along the lines of the CSA causing a change in the resistance reading ?? Pls advise
Many Thanks

 

[ricicle]

It doesn't matter what colour cable you use as the link although if you use one of a different colour to the wires in the CU then it might stand out a little to remind you to remove it when you've finished the test.
As for CSA it won't really make a lot of of difference to the overall reading with that small length in circuit.

 

[RF Lighting]

Colour is not important, and CSA is not really a huge issue due to the very short length of the link. Something like 2.5mm² would be fine.


You can remove the live from the MCB and connect it directly into the earth bar at the CU for example to avoid having to use a link at all if you wanted to.

You may find linking out easier if you by a proper lead with crocodile clips on either end.

 

[thomo27]

Thanks for your replys they are much appreciated.

The trainers method was to remove a conductor and connect it straight to the Earth bar at the CU, the CU only has 2 MCB's on so it looked a simple way at the time plus the CU was at lovely heiht were no obstructions , when I looked at my CU things weren't as simple which is why I feel the link would be better

Cheers

Ste

 

[saxondale]

sorry but I really think you ought to take a step back before you carry on, your clearly not ready to touch real life mains

 

[ricicle]

sorry but I really think you ought to take a step back before you carry on, your clearly not ready to touch real life mains

Don't be silly.

 

[Pensdown]

the CU only has 2 MCB's on so it looked a simple way at the time plus the CU was at lovely heiht were no obstructions , when I looked at my CU things weren't as simple which is why I feel the link would be better

Cheers

Ste

As RF has said you can use either method and it's good that you've found out for yourself theres a difference between a college CU and a real CU!

 

[DESL]

sorry but I really think you ought to take a step back before you carry on, your clearly not ready to touch real life mains

Don't be silly.

I'll second that - we all had to learn some time and we were learning well I was learning I didn't have the luxury of asking questions on fora such as this.

 

[ebee]

If you simply limk Ph to cpc say at the earthbar or with a link then you might introduce parallel earth paths into the reading, whilst if you remove both and link them together then this reduces this risk somewhat.

 

[saxondale]

sorry but I really think you ought to take a step back before you carry on, your clearly not ready to touch real life mains

Don't be silly.

the guys worried about what color he should use for a test link, basic understanding of how things work is missing here - if he thinks the COLOR is going to make a difference to his test then he obviously isnt out in the real world yet, put the test meter back in the cupboard and get trained first

 

[thomo27]

Saxondale- I appreciate your concerns and with reference to the colour of the cable I can understand why you would think 'hang on step back a min ' in all honesty I was pretty sure I could use any colour but the CSA I wasn't sure on'

You say I'm not in the real world which couldn't be more true I'm doing a C&G level 2 2330 so I am still training , level 3 will be next year and we will cover testing however I wanted to try and get a headstart , if I cant practice on my own CU then who's CU can I practice on!

 

[ColJack]

since the recomended way of doing ring mains it to remove all the ends and cross connect them in connector blocks, then the most common practice is to use those same terminal blocks and take both live and earth out and connect in the block.

that way there is NO chance of accidentally forgetting to remove the link and popping the breaker when you try to re-energise the circuit..

(it also removes any parallel earth paths should you be using something like armoured or conduit, that might give a live/cpc reading even with a broken or missing cpc.. )

 

[saxondale]

Saxondale- I appreciate your concerns and with reference to the colour of the cable I can understand why you would think 'hang on step back a min ' in all honesty I was pretty sure I could use any colour but the CSA I wasn't sure on'

You say I'm not in the real world which couldn't be more true I'm doing a C&G level 2 2330 so I am still training , level 3 will be next year and we will cover testing however I wanted to try and get a headstart , if I cant practice on my own CU then who's CU can I practice on!

no problem son, if my caustic posts make one person stop to think before they get hurt then I can take the flack from the others. Take your time and take care


good luck with your training

 

[thomo27]

no problem son, if my caustic posts make one person stop to think before they get hurt then I can take the flack from the others.

No probs & thankyou

merry christmas