Breaking capacity

[zupos40]

Yes I realise that, my question is if the switch was closed would it impact the reading, sorry if Im being padantic but I like to FULLY understand things

No because the cb/fuses in CCU should be switched/off removed, even if the main switch is on, or as you asked it may effect the reading.

 

[Richard3009]

It's just that I know adding load alters impedance, basic principle so it needs to be taken out of the equation for the external loop measurement, not clearly stated on the guidance notes.

 

[Lou7]

Main switch can be on or off will not make any difference, you test on supply side anyway.

 

[Richard3009]

It makes no difference as long as the final circuit breakers/fuses are open circuit, if they are closed when the test is done then don't mesh characteristics come into play?

Its just that guidance note 3 does not make it clear and you would think it would.

 

[zupos40]

As ElectricAL previously stated it would not matter, if you possess an ELZ/ PFC tester are are feel comptent to do so, go and test your own property with the supply on and supply off.

It great wanting to know every thing, but we are practical electricians, may be you should address this question to IET blog or IEEE etc.

I do know that my ELZ/PFC tester has an operating tolerance of +/- 20%, so if the meter not that accurate, then I do not think they are to worried about about any errors due to mesh loading.

I recently learned that for supplies upto 100A and protected by BS1361 type II as long as your measured value does not exceed 16kA and the CCU complies with BS 60439-3, then the installation will comply, so do not worry, get out there and as I previously said if competent get testing.

 

[Richard3009]

Point taken guess I have exhausted the subject next continuity

 

[electricAl]

next continuity

Oh no!

(a sense of humour always helps - sometimes it`s necessary!)

Thanks to Zupos (hitting the button over >there > right now> hint, hint Richard ) we get to do this all over again...yipee!

Ah well, something to while away the hours with, i guess...