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Old 17-04-2008   #5 (permalink)
Ross Trician
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Join Date: Jan 2008
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Default Re: testing for Ze and PFC.

evening chaps,
just to fill you in on a few more bits and to make things a bit clearer.

The incoming supply mis 3 phase which then uses the individual phases to feed various isolators and dis boards etc.

these are somer of the test results I did get.

ring was, L-L, 0.69 ohms. N-N was 0.66 ohms, cpc-cpc was 0.98 ohm.
L-N figure 8 1.34 ohm.
L-E fihure 8 was 1.56 ohm.
R1+R2 was 0.45ohms.
Ring Zs was 3.64ohms

Shakey, you say that the pfc is the right reading but needs to be doubled because it is 3 phase, can you tell me what difference that makes at the C/U as it is only fed with a live and neutral.

also can some of you who are more knowledgeable than me confirm I am interpreting this right,
in GN3 it states the max Zs for a type 1, 16 Amp, bs3871 CB is 3 ohms?
and for 32Amp CB it is 1.5ohms.
therefore the ZS readings I have are too high and presumably due to there being no earthing arangments???

also you say about putting a spike in for the whole system, would this then not make me "responsible" for the whole system?
my thoughts were to simply provide the earthing for the instalation I am working on and if they wish to "put right" the rest of the system then that would be a seperate issue.

I am initially working to the 16th, going on the 17th update course in couple of weeks.
could I put an rcd unit inline after the isolator to cover the whole system rather than changing both boards, advice on you ideas of instalation experience appreciated.

thanks Ross

Last edited by Ross Trician; 17-04-2008 at 07:21 PM. Reason: aditional information.
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