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