Siemens SINAMICS S120 - Page 125

Line Connection Booksize
2.13 Line connection variants
Booksize power units
Manual, (GH2), 06/2008, 6SL3097-2AC00-0BP6
125
Fuses
For timely tripping of fuses, the loop resistance as well as the vector group of the line
supply transformer being fed must satisfy the requirement that the touch voltage of the
devices is switched off by the provided fuses within the permissible tripping time (see figure
below, in accordance with EN 61800-5-1 Ed. 2).
10
100
1000
10 000
25 V AC
AC -2
60 V DC
DC-2
AC -2 DC-2
30 V AC
AC -2
250 V
10 100 1000
7RXFKYROWDJH9
'HFLVLYHYROWDJHFODVV$
7LPHPV
Figure 2-49 Permissible tripping time of fuses
The boundary conditions indicated above also serve to avoid a fire in case of a fault. If you
do not comply with these boundary conditions, you must take additional measures, e.g.
residual current transformer.
Fuse and plant conditions such as loop resistance and short-circuit power must be
harmonized to one another so that the limit curve is not exceeded. This guarantees the
shock-hazard protection.