Derating depending on the ambient temperature
The following figure shows the IN reduction depending on the ambient temperature and the nominal mains voltage Vline:
If you supply the device with a backup voltage of DC 24 V externally, the IN reduction (derating) is always 3 %/K. The maximum permissible ambient temperatures remain unchanged at 55 °C or 60 °C (depending on version).
Derating
The following table shows the IN reduction of size 2 device depending on the ambient temperature and the nominal mains voltage Vline:
Ambient temperature | IN reduction | ||
|---|---|---|---|
CM3C.. /D..0070.. | CM3C.. /D..0095.. | ||
Vline > 460 V | Vline = 400 V | Vline > 460 V | |
30 °C to 35 °C | – | – | 2 % IN/K |
35 °C to 40 °C | – | 1 % IN/K | 2 % IN/K |
40 °C to 55 °C | 3.5 % IN/K | 3 % IN/K | 3 % IN/K |
55 °C to 60 °C | – | 3 % IN/K | – |
Example:
Calculation of the effective motor current of drive unit CM3C../D..0095.. with:
- Ambient temperature
ϑ= 45 °C - Nominal mains voltage Vline = 460 V
IN reduction | = 2 % IN/K × (40 °C - 30 °C) + 3 % IN/K × (45 °C - 40 °C) = 2 % IN/K × 10 K + 3 % IN/K × 5 K = 20 % IN + 15 % IN = 35 % IN |
Motor current | = 100 % IN - 35 % IN = 65 % IN |
Under these conditions, the effective motor current of drive unit CM3C../D..0095.. reduces to 65 % of the nominal output current IN.
