text: <s>[INST] PF40P From DC Supply Hi Folks, Just wondering if anyone has had any experience in running a PF40P drive from a DC Supply? The drive we are looking at is probably the 22D-B017H204 (240V, 3-phase, 3.7kW). However, the user manual is a bit vague as to the Do's & Don'ts of using a DC supply, and whether it can only be done with a C-frame unit. Any thoughts or experiences would be much appreciated! Thanks, Simon. [/INST] I was unaware the 40P could handle common bus until this post. Other 4 class drives do not have the DC+ connection in the drive so you would not be able to supply DC. I have done DC supply to 700VC drives and there really isn't anything too special. The only trick is turning on the DC supply to the drive, this must be done gradually to allow the capacitors in the drive to ramp up to voltage. This is done automatically in the Rockwell DC bus supplies. Also, if you have a contactor breaking the DC to the drive you need the Digital Input assigned to Precharge Enable like it says in the book. This will force the drive into precharge when the drive is powered back up. If you just closed the contactors the DC supply sees the capacitors in the drive as a direct short, the precharge circuit adds a resistor into the circuit to limit the inrush current. What is the source of DC at what voltage? Why are you using a DC supply? \\n </s>