Initial sequence

[pauly007]

Hi. Could someone tell me after Ze test is it then Pfc test with Zs after this is how my tutor says it is because the cover is already off after doing Ze so then do Pfc test and put the cover of CU back on and perform Zs. But in GN3 it says earth fault loop impedance which I assume is both Ze and ZS then PFC. Thanks

 

[Pete999]

Sequence of tests Page 90 OSG 612 BGB Hope this helps

 

[telectrix]

Ze first with MEC dissed and the installation isolated. then reconnect MEC and get PFC. refit CU cover and re-energise installation, then Zs.

 

[gazj82]

Don't forget to double your PFC reading on a 3 phase system, especially if your preparing for your AM2.

 

[telectrix]

or measure phase -phase. and i prefer to use the 1.732 factor rather than doubling it. that's for youngsters who need a calculator to count their toes.

 

[gazj82]

or measure phase -phase. and i prefer to use the 1.732 factor rather than doubling it. that's for youngsters who need a calculator to count their toes.

Or for when your smart phone calculator c***s out! :smile5:

 

[SirKit Breaker]

or measure phase -phase. and i prefer to use the 1.732 factor rather than doubling it. that's for youngsters who need a calculator to count their toes.

Tel, phase to phase is not allowed, it is too dangerous, and some test kit will not do it without blowing yer face off!. Doubling the PFC is the preferred method, as it err's on the side of caution.

Cheers..........Howard

 

[telectrix]

agreed, howard, but if working with 3 phase , one should have the correct gear. the only problem with the x 2 is if your resulting value for pfc exceeds the max. for the ocpd. looks bad on a cert.

 

[Badged01]

.... i prefer to use the 1.732 factor ......

Lot easier if you use root 3 --- saves messing around with decimal points!

 

[Engineer54]

Tel, phase to phase is not allowed, it is too dangerous, and some test kit will not do it without blowing yer face off!. Doubling the PFC is the preferred method, as it err's on the side of caution.

Cheers..........Howard

What do you mean ''phase to phase is not allowed, because it's too dangerous''??

I've been testing 3 phase PFC etc, phase to phase ....for ever!! Are you saying that test equipment manufactures that include this facility in their test equipment are encouraging it's users to break some sort of law??
Come to that, exactly where does it state this stipulation, that phase to phase testing is not allowed??

 

[Sintra]

I must also be a danger to myself and my equipment lol. As stated before if working on 3 phase you should have the correct equipment and be competent in its use. Why calculate something when it can be measured safely.

 

[SirKit Breaker]

I am not disagreeing with you, i am just telling you how it is. Read and understand the EAWR. The problem with the people who write all this legislation etc, consider ALL of us to be thick Electricians, and so try to minimise danger and if we go against the law and it goes pear shaped then we cop for it.

So please don't shoot the messenger.

Cheers............Howard

 

[wozz]

is it possible to have the section in question put on here for clarification?

 

[GMES]

Forget the phase to phase test , they encourage them to even calculate zs, s it is a live test and is not needed.
I had a lad for 2 weeks work experience and he nearly fainted when i performed one in front of him!.
He had been told on his 5 week course that it was not the done thing now!! Beggars belief.

 

[trev]

What is now deemed to be essential H&S really boils my wee. How come properly trained (or supposedly properly trained) electricians are now not skilled enough to carry out a live test or two without endangering themselves or other people?
Like most I was taught how to do these things and many others that would now curl the hair of an on site H&S bod. I've worked live when there's been no other option, I've done so after carrying out my own risk assessment and putting a method statement in my own head. I've never needed someone with a clipboard and no electrical knowledge to stand behind me telling me what I'm doing is either right or wrong.
The entire world is going to hell in a handcart

 

[wozz]

Forget the phase to phase test , they encourage them to even calculate zs, s it is a live test and is not needed.
I had a lad for 2 weeks work experience and he nearly fainted when i performed one in front of him!.
He had been told on his 5 week course that it was not the done thing now!! Beggars belief.

the only organisation ive heard promoting calc Zs is the NIC.

Im all for reducing risk ect, but i would like to see the wording for my own interpretation.

 

[trev]

the NIC.

Growl!

 

[GMES]

Forget the phase to phase test , they encourage them to even calculate zs, s it is a live test and is not needed.
I had a lad for 2 weeks work experience and he nearly fainted when i performed one in front of him!.
He had been told on his 5 week course that it was not the done thing now!! Beggars belief.

Sorry guys typo, I am sure you realised I mean't to say they emcourage to not do a zs.
And I am same as you Trev worked live many many times and still do,and I am still here, it's called common sense, intellegence and a respect for what I am working with. However I don't expect clipboard Kev to understand that.

 

[Plonker 3]

How do you calculate Zs if you can't do a live test?

 

[trev]

How do you calculate Zs if you can't do a live test?

Ze+(r1+r2)=Zs

 

[Plonker 3]

And of it's fed from a sub DB fed from a sub DB? No past results available? Back to the old dangerous live testing then isn't it.

 

[Plonker 3]

All this carping on about no live testing, you can't work live is just to protect the incompetent/unqualified otherwise known as Dave down or the pub or Electrical Trainee.

 

[Silly Sausage]

Ze+(r1+r2)=Zs

Isn't determining Ze a live test?!

 

[GMES]

I'm guessing the schemes will accept a ze by enquiry and a zs by calculation thus only leaving the dead tests to be carried out by the pet mong sorry I mean short course trained operative!!

 

[Silly Sausage]

So, by not being allowed to do any live testing, high Z ees (due to external supply faults whathaveyou), wouldn't get picked up.
It's all bollox!

 

[GMES]

So, by not being allowed to do any live testing, high Z ees (due to external supply faults whathaveyou), wouldn't get picked up.
It's all bollox!

I fully agree mate but sadly with the way things are governed now, it will be the future way for all newcomers to the trade.

 

[wozz]

Growl!

dont follow, enlighten me please.

 

[trev]

Isn't determining Ze a live test?!

Ze is allowable by enquiry.
Yes, I know.....

 

[trev]

dont follow, enlighten me please.

I despise the NIC mate

 

[wozz]

I see, them and the QS system is one of the biggest problems in the industry.

 

[Sintra]

This is all total bs. Ze by enquiry is nonsense given the amount of times if seen a TN system with a stupidly high Ze. Also a Zs is the only test that encompasses the complete circuit including protective devices which can have high impedances which all this calculating rubbish will not find. I though the point of testing was to prove the installation is safe for the users.

 

[trev]

I see, them and the QS system is one of the biggest problems in the industry.

Which brings me back to my crusade against them.....

 

[trev]

This is all total bs. Ze by enquiry is nonsense

And as you know, most of us know that. There is no substitute for measurement

 

[shanky887614]

What is now deemed to be essential H&S really boils my wee. How come properly trained (or supposedly properly trained) electricians are now not skilled enough to carry out a live test or two without endangering themselves or other people?
Like most I was taught how to do these things and many others that would now curl the hair of an on site H&S bod. I've worked live when there's been no other option, I've done so after carrying out my own risk assessment and putting a method statement in my own head. I've never needed someone with a clipboard and no electrical knowledge to stand behind me telling me what I'm doing is either right or wrong.
The entire world is going to hell in a handcart

my method statement is quite simple, lock the doors with key in lock/use other deterants to keep them occupied.

last resort is a lookout to sing/whistle along with song when he spots anyone around

 

[Engineer54]

I am not disagreeing with you, i am just telling you how it is. Read and understand the EAWR. The problem with the people who write all this legislation etc, consider ALL of us to be thick Electricians, and so try to minimise danger and if we go against the law and it goes pear shaped then we cop for it.

So please don't shoot the messenger.

Cheers............Howard

Are you sure the live EAWR working rules rules apply to testing procedures??

All this load of old crap about live working, doesn't apply to electrical testing, if it did, we all might as well pack our bags and call it a day!! Live tests are an essential necessity full stop, no matter what these half wits have to say... I suppose next, they'll be telling you, voltage testers cannot be used to test /check voltages above 50 Volts, or that you can't test/check phase rotation, ....and so on and so on!!

Hmm, ...Just a thought, so what does EAWR state about voltage testing and phasing out testing on live MV/HV systems, or is that against EAWR too?? lol!!!

Jesus the UK has got to be fast becoming the laughing stock of Europe, if not the world...

 

[Silly Sausage]

I'm not sure what Howard is referring to within EAWR.
From memory, it only states that Live Working should be avoided if at all possible.
I'm not checking at this hour!

 

[shanky887614]

I'm not sure what Howard is referring to within EAWR.
From memory, it only states that Live Working should be avoided if at all possible.
I'm not checking at this hour!

your right there.

it is along the line of "live working should only be undertaken if it is reasonably unpractical to work dead"

 

[Silly Sausage]

your right there.

it is along the line of "live working should only be undertaken if it is reasonably unpractical to work dead"

Good to see you know your 'Statutory Instruments'.
Not so sure about the dubious ability of being able to quote them at 12'o'clock on Friday night though!

 

[shanky887614]

Good to see you know your 'Statutory Instruments'.
Not so sure about the dubious ability of being able to quote them at 12'o'clock on Friday night though!

good considering I havent even looked in book or used that info for two years, ive got a good memory.

 

[ferg]

IIRC, which I might not, when I was doing the 2391 we were told working live should be avoided unless absolutely necessary, so therefore if it can be calculated.....

I knew it was nonsense then and I know it is nonsense now.
My theory was... do as you are told pass the exam and when in the real world do it properly.

This is one of the main areas where Short courses and college only routes let down trainees.

Obviously a respect for those pesky little electrons is healthy.
In the real world we need to work live from time to time so being able to do it safely is of the utmost importance.

 

[wozz]

If it is that the wording has been there since when? and why now is it being interpreted in this way?

The culture should be minimize risk wherever possible, no point in earning money if you dont get to go home at the end of day.

After all DNO personnel around here when changing heads are only allowed one exposed conductor, and when doing joints with shear offs they have no exposed conductors. They have gone that way our industry is probably looking that way...

BUT, this measurement is essential if the safety of the installation is to be assessed and to some extent the users of that installation. The measurement can usually be taken from a position of relative safety ie in a fuseboard with internal guards with equipment to GS38 with competent personnel, live parts are only really accessible with a tool rather than a finger or a face! Sometimes standing on a rubber mat haha. I cant see too many problems in that case, after all the designer of the installation would have worked to a quoted PFC from the DNO this would have to be verified.

 

[edexlab]

Lack of experience , knowledge is going to notch up a higher body count, for people who haven't been taught how to do this safely

As we all know life is full of risks the people with the least experience will be the most at risk

If the trainees aren't intelligent enough to take in this information and use it as countless others have , before them,
then the training centres need to take a better look at the candidates rather than making the training fit the candidate
In my opinion the most dangerous electricians I've met are always the ones I wonder how they were accepted onto a course/apprenticeship