Discuss Sequence of tests in guidance note 3 (initial verification) in the UK Electrical Forum area at ElectriciansForums.net
I would measure Zs on sockets using a plug adaptor and calculate the rest?So how would you do your ZS test at board...Think about it...Disconnect Main Earth do ZE test Reconnect Main Earth Do ZS.....How can you do a ZS at DB if cover is on
How come the sequence of tests in guidance note 3 is that the Zs test comes before the PFC test?
Isn't it normal to do PFC test before the Zs test? Because then you can do your PFC test, put the board cover on and energize the board without coming back to do the PFC test.
not on all meters. on the megger 1552/3 they are separate tests. don't know about the 1700 series.I can't afford anything that fancy.
A bit odd as the measurement (as already pointed out) basically reveals Zs from observing delta-V while switching a known delta-I, and then from the voltage, computes PFC = V / Zsif you zoom the pic, it shows separate tests for pfc. both on hi current and no-trip.
I meant Zs of final circuits. Not the Zs at DB for which you need the board to be open.Can you post a picture of the list of tests you are referring to, there may be a detail you have missed.
Which Zs test is it referring to? The Zs at the DB or the Zs of final circuits?
PFC is calculated and displayed by the test meter for every loop impedance test, it's not possible to carry them out as seperate tests.
One person says Ze another Zs at DB can we please come to a common denominator? If it's a DB test, then it's a Zs at DB. And that's not even my question.if you followed the correct Sequence of tests you just do You Earth Fault Loop Impedance Ze at the board and add your result to your R1+R2 then do your PFC tests.
I'm not talking about Ze/Zs at DB at all. It's a test done on a dead board right? So is PFC test i.e. I don't need to energize the board. Only for the Zs of final circuits I need to energize the board. So I thought would it make sense to change the sequence, do the PFC at DB then the Zs of final circuits.Do you mean Ze, the impedance at the board, before you do the Zs, impedance at end of circuit?
In practically all cases you measure Zs/Ze along with the related PFC using your MFT.
If it is a dead board then you can't measure the supply PFC - that (i.e. Ze) is a property of the supply itself.I'm not talking about Ze/Zs at DB at all. It's a test done on a dead board right? So is PFC test i.e. I don't need to energize the board. Only for the Zs of final circuits I need to energize the board. So I thought would it make sense to change the sequence, do the PFC at DB then the Zs of final circuits.
I meant Zs of final circuits. Not the Zs at DB for which you need the board to be open.
After insulation resistance I'd do supply polarity, Zs at DB, then PFC, then put the lid back on, energise the board, then do the Zs of final circuits.
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One person says Ze another Zs at DB can we please come to a common denominator? If it's a DB test, then it's a Zs at DB. And that's not even my question.
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I'm not talking about Ze/Zs at DB at all. It's a test done on a dead board right? So is PFC test i.e. I don't need to energize the board. Only for the Zs of final circuits I need to energize the board. So I thought would it make sense to change the sequence, do the PFC at DB then the Zs of final circuits.
By dead I meant isolated at the main switch. We measure at the live incoming side between L N and Earth bar.If it is a dead board then you can't measure the supply PFC - that (i.e. Ze) is a property of the supply itself.
I guess I'm thinking commercial sites, where you get Ze of Ze of Ze so only the main is true Ze, the rest are Zs at Db is it not? If you were given Ze by the DNO and measured Ze at DB, and they would differ, would that mean the board is sub main? But in any case which of the two "Ze" would you choose to calculate the Zs of final circuits?and as was pointed out to me on here Zs at DB is only really useful for a Sub-consumer unit.
Do you do tutorials?I guess I'm thinking commercial sites, where you get Ze of Ze of Ze so only the main is true Ze, the rest are Zs at Db is it not? If you were given Ze by the DNO and measured Ze at DB, and they would differ, would that mean the board is sub main? But in any case which of the two "Ze" would you choose to calculate the Zs of final circuits?
Reply to Sequence of tests in guidance note 3 (initial verification) in the UK Electrical Forum area at ElectriciansForums.net
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