I think you have a running machine--do you know how many years of this machine?

from the picture the RED led on --means --there is missing phase in your input power 3 phase AC 

or the power level lower than your standard setting ( setting for 480VAC but only 407VAC) 

please get eletrician to check from transfomer -->CNC system control cabinet main power breaker-->to Siemens U/E module input. 

If all power section No problem , you need replace U/E module

Stipe91

Hello everyone,

We have a problem with the U/E module on a 4-axis CNC machine consisting of the following hardware configuration:

- Siemens 6FC5210-0DF22-2AA0 Sinumerik PCU 1.2GHz, 256RAM

- Siemens 6SN1146-1AB00-0BA1 Simodrive U/E module int-ext.5/10KW (VERSION A)

- Siemens 6FC5447-0AA00-0AA1 LT-MODUL

- Siemens 6FC5410-0AY03-1AA0 Sinumerik 810D CCU3.4 software vers. 6.5

From the pictures in the attachment, you can see that the red 3rd LED is lit, and in the manual I found that it indicates that there is a problem with the power supply.

I checked the voltage at the input and it is 407V, while the voltage on the DC bus is around 590V (after I give permission from the auxiliary circuit).

Thanks in advance!

There must NOT be relation with PCU2, I suggest you replace U/E module