Derating As A Function Of The Ambient Temperature, Pulse Frequency, And Installation Altitude - Siemens S120 Manual

2.6 Derating as a function of the ambient temperature, pulse frequency, and installation altitude

2.6 Derating as a function of the ambient temperature, pulse frequency,
and installation altitude
Preliminary remark
The air pressure and therefore the air density drop at altitudes above sea level. At these
altitudes, the same quantity of air does not have the same cooling effect and the air gap
between two electrical conductors can only insulate a lower voltage. Typical values for air
pressure are summarized in the table below:
Table 2- 4
Installation altitude above
sea level in [m]
Air pressure in mbar [kPa]
Derating
The Power Modules are designed for operation under the following conditions:
● Ambient temperature 0° C up to 40° C
● The pulse frequency specified for each Power Module
● Installation altitude of up to 1000 m above MSL for Blocksize Power Modules.
● Up to 2000 m above MSL for Chassis Power Modules.
If you operate the Power Modules at higher ambient temperatures, pulse frequencies, or
installation altitudes, you must reduce the output current.
You will find the reduction factors for the individual units in the technical data of the relevant
Power Modules.
The maximum permissible ambient temperature for all Power Modules is 55° C.
A TN or TT system with grounded neutral point is required (no grounded phase conductor)
for installation altitudes above 2000 m. If the neutral point is not grounded, an isolating
transformer must be connected upstream for which the secondary windings are grounded at
the neutral point.
A reduction of the line supply voltage phase-phase is not necessary.
AC Drive
Manual, (GH6), 04/2014, 6SL3097-4AL00-0BP4
Air pressure for various installation altitudes
0
100
1000 2000
90 80
System overview
3000 4000
70 62
37