Derating - Siemens SINAMICS S110 Manual

2.5

Derating

The Power Modules are designed for operation under the following conditions:
● Installation altitude up to 1000 m above sea level
● Ambient temperature 0 °C to 40 °C
● Rated pulse frequency according to the Technical Data of the Power Module
● Output frequency above 22 Hz (FSA - FSC) or 10 Hz (FSD - FSE)
Derating as a function of the installation altitude
The air pressure and therefore the air density are lower at higher altitudes above mean sea
level (MSL). The same quantity of air does not have the same cooling effect and the
clearance between 2 electrical conductors can only isolate a lower voltage. Typical values
for air pressure are summarized in the table below:
Table 2- 4
Installation altitude above
sea level in [m]
Installation altitude above
sea level in [ft]
Air pressure in mbar [kPa]
If the Power Modules are operated at installation altitudes > 1000 m above sea level, you
must reduce the maximum possible output current as follows:
Figure 2-3
A TN or TT system with grounded neutral point is required (no grounded line conductor) for
installation altitudes above 2000 m. If the neutral point is not grounded, you must connect an
isolating transformer upstream, the secondary side of which is then grounded at the neutral
point.
A reduction of the line voltage phase-phase is not necessary.
SINAMICS S110
Manual, 07/2015, 6SL3097-4AC10-0BP5
Air pressure for various installation altitudes
0
0
100
Reduction of the output current as a function of the installation altitude above sea level
1000 2000
3280 6561
90 80
System overview
2.5 Derating
3000 4000
9842 13123
70 62
31