Siemens SINAMICS G120 Operating Instructions Manual page 101

Additional options for wiring the digital inputs
Connecting P-switching contacts with an external
Connecting M-switching contacts with an external
NOTICE
Damage to the CU240E-2 PN and CU240E-2 PN-F Control Units in the event of a short-
circuit of the 24 V output
It is possible that the Control Units are defective if the following conditions occur
simultaneously:
1. A short-circuit at the 24 V output occurs at terminal 9 when the inverter is operational.
2. The ambient temperature is at the upper permitted limit.
3. You have connected an external 24 V supply to terminals 31 and 32, and the voltage at
In order to rule out damage to the Control Units, you have to prevent all three conditions
occurring simultaneously.
Converter with the CU240B-2 and CU240E-2 Control Units
Operating Instructions, 01/2016, FW V4.7 SP6, A5E34259001B AC
power supply
power supply
terminal 31 is at the upper permitted limit.
4.6 Installing Control Unit
If you wish to connect the potential of
an external power supply with the po-
tential of the internal inverter power
supply, then you must connect "GND"
with terminals 34and 69.
Connect terminals 69 and 34 with one
another.
Installing
101