T
trigger
Hi Everyone,
I am a new member on the forum! (Although I have for long read through the various topics)
I have just recently completed and passed successfully the 2394/2395 C&G exams.
I had been testing for a good few years but finally managed to get the funds to take the proper courses.
However that is not why I am posting this, just wanted to clarify that I am competent, fully versed etc.
So, here we go!
Using my Fluke 1562B which was calibrated last month, I have been undertaking a test on a large domestic installation.
After completing my dead tests, and proceeding with the live testing, I was struck with a problem;
I was getting unusually high Zs readings on all the lighting circuits which implemented LED drivers. We fit JCC LED 7 Dimmable so that we comply with Part L1A etc.
Some of these readings were way above the 80% rule of thumb and I was sure that they were not an accurate portrayal of the Zs, after all, as I had the calculation of the Ze + (R1+R2) I had a rough idea of the measurement.
I'm aware I could use the calculation but considering that the dead tests were done previously I wanted to ensure that I had not lost the CPC at any of the final points of the circuit over the last few weeks.
I rung the JCC technical department regarding this and they explained that it is a common problem and that LED down lights with built in drivers 'don't like the earth fault test'
Without taking every light apart and joining them together, which is completely impractical, labour intensive and quite frankly not going to happen in a house with 300 + down lights in.
I'm not sure if anyone on this forum has the problem, it seems a simple solution would be if the manufacturer would integrate a small switch on the side of something, but anyway that seems a long shot.
Anyone able to help?!
PS. Apologies if this has been brought to light (pardon the pun) previously.
Thanks in advance.
Tom
I am a new member on the forum! (Although I have for long read through the various topics)
I have just recently completed and passed successfully the 2394/2395 C&G exams.
I had been testing for a good few years but finally managed to get the funds to take the proper courses.
However that is not why I am posting this, just wanted to clarify that I am competent, fully versed etc.
So, here we go!
Using my Fluke 1562B which was calibrated last month, I have been undertaking a test on a large domestic installation.
After completing my dead tests, and proceeding with the live testing, I was struck with a problem;
I was getting unusually high Zs readings on all the lighting circuits which implemented LED drivers. We fit JCC LED 7 Dimmable so that we comply with Part L1A etc.
Some of these readings were way above the 80% rule of thumb and I was sure that they were not an accurate portrayal of the Zs, after all, as I had the calculation of the Ze + (R1+R2) I had a rough idea of the measurement.
I'm aware I could use the calculation but considering that the dead tests were done previously I wanted to ensure that I had not lost the CPC at any of the final points of the circuit over the last few weeks.
I rung the JCC technical department regarding this and they explained that it is a common problem and that LED down lights with built in drivers 'don't like the earth fault test'
Without taking every light apart and joining them together, which is completely impractical, labour intensive and quite frankly not going to happen in a house with 300 + down lights in.
I'm not sure if anyone on this forum has the problem, it seems a simple solution would be if the manufacturer would integrate a small switch on the side of something, but anyway that seems a long shot.
Anyone able to help?!
PS. Apologies if this has been brought to light (pardon the pun) previously.
Thanks in advance.
Tom
