Derating Measures - Siemens SINAMICS S120 Manual

System overview
2.11 Derating data
Installation altitudes greater than 2000 to 5000 m above sea level
If SINAMICS S120 Cabinet Modules are operated at installation altitudes greater than 2000
m above sea level, then it must be taken into account that with increasing installation
altitude, the air pressure and therefore the density of the air decreases. The cooling effect as
well as the insulating capability of the air decrease as a result of the lower air density.
Installation altitudes greater than 2000 to 5000 m can be achieved if the derating measures
in the following chapter are applied.
2.11.1.2

Derating measures

Installation altitudes greater than 2000 to 5000 m can be achieved if the following derating
measures are applied. These measures apply for the following drive configurations with
SINAMICS S120 Cabinet Modules:
● Drives with Basic Line Modules at all voltage levels
● Drives with Smart Line Modules in all voltage levels
● Drives with Active Line Modules in the voltage level 3 AC 380 to 480 V
Reducing the ambient temperature and the output current
As a result of the lower cooling effect, on one hand, the ambient temperature must be
reduced, and on the other hand, the power loss in the Cabinet Module must also be reduced
by reducing the output current; whereby ambient temperatures less than 40 °C can be
factored in as countermeasure for compensation. The following tables specify the
permissible output currents as a function of the installation altitude and ambient temperature
for the various degrees of protection. The specified values already take into account the
permissible compensation between installation altitude and ambient temperature less than
40 °C (air intake temperature where the air enters the Cabinet Module). The values apply
under the precondition that the cooling air flow through the devices – as specified in the
technical data – is guaranteed as a result of the cabinet installation.
Table 2- 5 Current derating as a function of ambient temperature (air intake temperature where the air enters the cabinet
unit) and installation altitude for cabinet units with degree of protection IP20 / IP21 / IP23 / IP43
Installation altitude
above sea level in m
0 ... 2000
... 2500
... 3000
... 3500
... 4000
... 4500
... 5000
36
(3 AC 380 to 480 V and 3 AC 500 to 690 V).
(3 AC 380 to 480 V and 3 AC 500 to 690 V).
(drives with Active Line Modules for 3 AC 500 to 690 V on request).
at an ambient temperature (air intake temperature) of
20 °C 25 °C
100 % 100 %
100 % 100 %
100 % 100 %
100 % 100 %
100 % 100 %
100 % 97.5 %
98.2 %
Current derating factor
30 °C 35 °C
100 % 100 %
100 % 100 %
100 % 98.7 %
100 %
96.3 %
40 °C 45 °C
100 % 93.3 %
96.3 %
Cabinet Modules
Manual, (GH5), 05/2010, A5E03263538A
50 °C
86.0 %