DC link components   
7.1 Control Supply Module CSM 
  SINAMICS S120 Combi 
160  Manual, 11/2017, 6SL3097-4AV00-0BP7 
 
Meaning of the LEDs on the Control Supply Module 
Table 7- 5  Meaning of the LEDs on the Control Supply Module  
Off  Off  Electronics power supply outside permissible tolerance 
range or temperature advance warning active 
– 
Green  Off  DC input voltage U
E DC
 < 280 ... 300 V 
Buffer operation not possible 
– 
Yellow  DC input voltage in the range 
360 ... 380 V < U
E DC
 < 820 V ± 3 % 
Buffer operation possible 
– 
Red  DC input voltage outside the tolerance range:  
E DC
E DC
Adjust DC input voltage