C200A18 Error on CB-Series UR10

Hi all, our UR10 arm recently started faulting on startup with error code C200A18, saying that the arm’s voltage is too low. This was after some doing some work in the control box. I have checked that the PSUs are delivering 48V to the safety control board. The energy eater is also receiving 48V, but no voltage is going to the arm. At startup, the voltage to the arm reaches a maximum of 0.3V before going back to 0. What might be some steps we can take to resolve this?

Hi,n
It’s probably the current distributor (p/n 172080). It is a relay device that controls switching ACV input to the 48v supplies. If the contacts get pitted (they can just do this over time) they will ‘‘bounce’’ and create this phenomenon. It’s an inexpensive part but if you contact your distributor they should be able to assist in troubleshooting. The CB3 service manual describes how to replace it clearly.