Please help 3 pahase isolation procedure

[thenugnug]

Hi there im new to this so be gentle,i am currently doing my 2330 and have a written exam on tuesday and need to find out the isolation procedure for a 3 phase and neutral supply. I have been told by the tutor that there is 10 combinations such as L1 - L2 L1 - L3 L1 - N and so on but i can only come up with about 6 0r 7 so can anybody please help as i dont want to fail. quick replys would be amazing guys,thanks

 

[sean123]

l1-e, l2-e,l3-e, l1-n, l2-n, l3-n, l1-l2, l1-l3, l2-l3, n-e

 

[GrannySmiff]

I am sure you know that is not the actuall safe isolation procedure and just the measurements to "prove" safe isolation which are within safe isolation as a whole.