[0] Advantages [TT] Safe and reliable [TN-S] Safest [TN-C] Cost [TN-C-S] Safety and cost [IT] 
Continuity of operation, cost
H i g h e s t
N / A
Y e s
L o w
N o
L e s s S a f e
L e a s t
D o u b l e f a u l t , o v e r v o l t a g e
C o n t i n u i t y o f o p e r a t i o n , c o s t