The lights are on!!

[Wayne Phillips]

Hello All...

My name's Wayne. I'm training to be an electrician and have loads of trivial questions that I hope you guys can help me out with.

Here goes with the first post:

Can someone explain in lovely simple language what is the difference between P.F.C. and P.S.C.C. and how do you calculate each one?

Thanks to all!!

Wayne :dizzy2:

 

[Dan]

Hello Wayne Phillips, welcome aboard. Enjoy the forum.

 

[MarkieSparkie]

Hi, welcome to the forum.

 

[Ducksy]

Hello Can someone explain in lovely simple language what is the difference between P.F.C. and P.S.C.C. and how do you calculate each one?

Thanks to all!!

Wayne :dizzy2:

Hey PFC is perspective earth fault current which is the max current that can flow between live conductors to earth.

PSCC is perspective short circuit current which is the max current that can flow in a short between live conductors.

PEFC can be worked out roughly by dividing nominal voltage with Ze so

230Uo/0.35Ze = 460PFC

But it is not that accurate so is will need to be carrying out using a perspective fault current tester.

Good luck.

 

[Wayne Phillips]

Thanks, Ducksy...short and sweet.

How accurate are the quoted figures for Ze? Is it best to measure by using instruments or believing the supplier? Thanks

Hey PFC is perspective earth fault current which is the max current that can flow between live conductors to earth.

PSCC is perspective short circuit current which is the max current that can flow in a short between live conductors.

PEFC can be worked out roughly by dividing nominal voltage with Ze so

230Uo/0.35Ze = 460PFC

But it is not that accurate so is will need to be carrying out using a perspective fault current tester.

Good luck.

 

[Ducksy]

How accurate are the quoted figures for Ze? Is it best to measure by using instruments or believing the supplier?

Well if you ask the DNO they will quote a tn-c-s as 0.35ohms and for tn-s its 0.8ohms..........in real life everyone uses a earth fault loop impedance tester to acquire Ze results.

wayne i would highly recommended a book called the electricians guide to the wiring regulations its got loads of information.

 

[Wayne Phillips]

Thanks, Ducksy...Do you mean BS:7671?

Thanks again.

Wayne

Well if you ask the DNO they will quote a tn-c-s as 0.35ohms and for tn-s its 0.8ohms..........in real life everyone uses a earth fault loop impedance tester to acquire Ze results.

wayne i would highly recommended a book called the electricians guide to the wiring regulations its got loads of information.

 

[Sintra]

Hi & welcome.

 

[Richard Burns]

Thanks, Ducksy...Do you mean BS:7671?

Thanks again.

Wayne

Ducksy means "The Electrician's Guide to the Building Regulations"
Note that the Building regulations have changed and Part P will change in April, however it still has a lot of useful and relevant information.

 

[Ducksy]

actually i mean this

The Electrician's Guide to the 17th Edition of the IEE Wiring Regulations BS 7671:2011 and Part P of the Building Regulations, 3rd ed: Amazon.co.uk: John F. Whitfield: Books

wish i knew how to link the pic lol

Both books the are very useful but the OSG and BS7671 are essential

 

[Richard Burns]

actually i mean this

The Electrician's Guide to the 17th Edition of the IEE Wiring Regulations BS 7671:2011 and Part P of the Building Regulations, 3rd ed: Amazon.co.uk: John F. Whitfield: Books

wish i knew how to link the pic lol

Both books the are very useful but the OSG and BS7671 are essential

Sorry about that, misunderstood which one you were talking about!
there is a button that allows you to insert an image in the tool bar.

 

[markc123]

Welcome along.

 

[sparkymalarky]

Welcome Welcome

 

[Wayne Phillips]

Thanks, Richard...I do have a copy of this and BS:7671

By the way, what are the April changes all about?

Regards,

Wayne

Ducksy means "The Electrician's Guide to the Building Regulations"
View attachment 17973Note that the Building regulations have changed and Part P will change in April, however it still has a lot of useful and relevant information.

 

[wade88]

It's actually prospective (as in potential current under x fault) not "perceptive" (as in what you perceive depending on your position the fault current to be) Perspective of course differs depending on what side of the pond you stand so to speak, but in this circumstance, perspective is irrelevant, whereas the prospective or potential may change due to a number of variables.

And, hello, welcome to the forum chap

 

[Sparkytlec]

Welcome Wayne.

The above book is a good one and so is the " on site guide" (it's a less formal version of the BS7671 regs)

 

[Sparkytlec]

The NICEIC provide a useful book on testing to. It's available on there website.

 

[Richard Burns]

By the way, what are the April changes all about?

Try these threads
http://www.electriciansforums.net/e...forum/69366-new-part-p-document-thoughts.html
http://www.electriciansforums.net/i...s/74057-third-party-part-p-inspections-2.html
http://www.electriciansforums.net/i...ons/74057-third-party-part-p-inspections.html

and this link Approved Document P

 

[Geordie Spark]

:welcome: