Help checking lighting circuit

[raustin]

Hi Guys

When checking a lighting circuit you obviously need to check at each point on the circuit, switch and light fitting.

What do you do when you can't get to the cable in the light fitting??

For example, in my kitchen I have 3 spot lights on a bar. I'm not able to remove the bar without damaging the ceiling, so this isn't an option. I can check the continuity of L1 and LN in the fitting, but can't check L2.

Any advice on what you do when this happens.

Rich

 

[telectrix]

do you mean R1,Rn,R2 ??? if its a metal fitting, you can clip on to any metal part, use a lightmate suitable for whatever lamp fitting it is.

 

[Farmelectrics]

do the r2 method wandering test lead and calculate the live test its what the niceic advise on there dvd

 

[IQ Electrical]

do the r2 method wandering test lead and calculate the live test its what the niceic advise on there dvd

Calculate Zs from an R2 reading?

Must be missing from my complete set of NICEIC dvd's!

 

[Farmelectrics]

zs = ze + R1 + R2 THEREFORE IF YOU HAVE THE ZE VALUE AND R2 VALUE YOU CAN CALCULATE YOUR ZS IS THAT NOT CORRECT

 

[IQ Electrical]

zs = ze + R1 + R2 THEREFORE IF YOU HAVE THE ZE VALUE AND R2 VALUE YOU CAN CALCULATE YOUR ZS IS THAT NOT CORRECT

Well no, where is R1 ?

 

[Farmelectrics]

This is shown on niceic perodic testing and inspection dvd or am i reading it wrong iq electrical interested to here your views

 

[Farmelectrics]

You can use test method 1 or test method 2 tony cable uses test method 2 on the niceic dvd watching it as we talk

 

[IQ Electrical]

This is shown on niceic perodic testing and inspection dvd or am i reading it wrong iq electrical interested to here your views

I think you might have misheard, you can't calculate Zs purely on an R2 reading with Ze, you need R1.

You can calculate R1 from R2 once you know the ratio of cross sectional area difference between line and cpc conductors but it's not really a prescribed method.

 

[telectrix]

yes, but you need R1 and R2 to add to Ze to calculate Zs. in the time taken to discuss this, you could have done the test, filled out the certificate, laid the ( female ) customer, had a cup of tea and still got home in time for Top Gear repeat on Dave.

 

[IQ Electrical]

yes, but you need R1 and R2 to add to Ze to calculate Zs. in the time taken to discuss this, you could have done the test, filled out the certificate, laid the ( female ) customer, had a cup of tea and still got home in time for Top Gear repeat on Dave.

I'm doing these inspections all wrong......

 

[chiplard]

do you mean R1,Rn,R2 ??? if its a metal fitting, you can clip on to any metal part, use a lightmate suitable for whatever lamp fitting it is.

You do need to careful doing this tho mate as there is nearly always some resistance between the metal fitting and the earth. ie plating, poor connections etc

It could cause unnecessary tail chasing of a high R1+R2 reading.

I always try and get to the earth terminal where possible.

 

[SirKit Breaker]

get a set of lightmates, fit the correct one into the lamp holder, shove the red lead in and poke the earth lead onto the metal fitting. When doing Zs shove the blue lead in as well and push your button, job done, and no more taking light fittings down. It was the best £50 i ever spent.

Cheers.........Howard

 

[Farmelectrics]

thats correct so you can find the zs from this calculation are company has been using this method for there perodics

 

[Farmelectrics]

iQ electrical i understand were your coming from there are easy methods im just talking about a particular job we were doing on raft lighting in a office area that was the method we used the conuctors were the same cross sectional area ie 1.5mm so if the r2 was 1 ohm r1 would be 0.50 ohms so we then calulated the zs on are engineers instructions long winded i know but there you go