Derating Factors - Siemens SIMOTICS S-1FK2 Configuration Manual

Description of the motors

2.4 Derating factors

2.4 Derating factors
Due to the decreasing air pressure in higher installation altitudes, the cooling of the motor
deteriorates. Therefore, reduce the power of the motor as the installation altitude increases.
Multiply the permissible torques or powers by the factors from the following table.
Reduce the torques and powers according to the values determined.
Factors for power derating depending on the installation altitude and the ambient temperature
Installation altitude above
Calculate the derating value for ambient temperatures that are not shown here and installation altitudes
below the maximum values by interpolating. For example: 40 °C at 1500 m above sea level = derating factor
0.965
Calculating the reduced characteristic curve
M
S1 red
M Reduced motor torque for S1 operation at the required installation altitude and ambient temperature
S1 red
M Motor torque for S1 operation at ambient temperature of 40 °C and
S1
1000 m above sea level (see Chapter "Data sheets and characteristic curves" in the Configuration
Manual)
n Motor speed
x Derating factor from the table "Factors for reducing the power..." above
d
28
sea level in m
1000
2000
3000
4000
(n) = x • M (n / xd)
d S1
Ambient temperature in °C
30 40
1.05 1
1 0.95
0.95 0.89
0.89 0.84
Configuration Manual, 02/2022, A5E46927724B AD
45 50
0.95 0.89
0.86 0.8
0.76 0.69
0.65 0.57
1FK2 Synchronous Motors for SINAMICS S120
55
0.84
0.73
0.62
0.47