3 phase supplies

[basic]

hi I could do with some help
how do you recogfnise what kind of type opf 3phase system is present in an installation i.e. tnc-s, tn-s

single phase I know,but three phase i don't - some pics or links would be great

 

[industryspark]

not all that different to single phase really.... the obvious signs......failing that call the suppliers.

 

[jondiy]

Earth from sheath of armour , its a TNS .

Earth from service head , would most likely be a TNCS, although it's still best to check with supplier - unless there is a sign saying ' Proctective Multiple Earthing'.

If you are asking these questions, maybe its best you stay away from 3 phase until you've learnt a bit more - remember crossing phases can give you 415v - stick that down a single phase distribution circuit line and you could blow a hell of a lot of stuff up! , and you really need to know about load balancing , sizing neutrals etc!

With a name like 'basic' , I'd literally , stick to the basics, whatever they may be for you! Is this out of curiosity, or are you actually delving into 3 working with phase gear ?

 

[basic]

actually I have 3 years experience on tools and are best part qualified as a sparky, I'm venturing into inspecting and testing,and with my present employer will be conducting or should i say participating with said tests.
my experience with three phase is limited and i just wanted some idea if there was any major difference in physical appearance from single phase, i understand nuetral sizing and balancing the loads of an installation with three phase its just that if you have'nt done it you can only ask people for help on such matters.

thanks again

 

[securespark]

how do you recogfnise what kind of type opf 3phase system is present in an installation i.e. tnc-s, tn-s

In the same way you would with single phase... TN-S is TN-S is TN-S whether it's 1P or 3P...

I take it you can ID 1P supplies adequately?

 

[CallEdsFirst]

The only change is the number of lives or phases! Earthing arrangements equate to the same as single phase!