m.2 Measures for protection automatic disconnection supply
For all types systems earthing following fundamental principles shall applied:
a) Earthing
Exposed conductive parts shall connected the earth means protective conductor.
.s.
b) Conventional voltage limit
The conventional voltage limit equal a.FUNDAMENTAL RULES FOR PROTECTION AGAINST ELECTRIC SHOCK 41
L1, L2, Phase conductors 1,2,3
or Line conductors 1,2,3
PE Protective conductor;
N Neutral conductor;
PEN PEN conductor.c.
Symbols for conductors according IEC 617 (1983):
protecctive conductor (PE)
neutral conductor (N)
PEN conductor (PEN)
5., r. 120 ripple-free d.c.
Figure 5. the
maximum prospective touch voltage which can occur exposed conductive parts under usual
conditions for indefinite time.2.2.6
TN-C-S system: one part the system neutral and protective function are combined a
single conductor, another part the system there are separate neutral and protective
conductors.2
