text: <s>[INST] F004 Fault on Powerflex 4M Summary: Inverters faulting on F004 during ramp-upHi all We have 4 inverters fitted in this particular panel are all failing on F004 as the individual motors are running up (only two motors run up at a time). They are reading 400V-405V at the inverter input terminals. I believe the fault level is based on the based on the drive rating (480V) and is a non-settable threshold. We lowered P001 to 380 and switched the display to D005 (DC Bus Voltage) and the display started at 575V and, when it fell over in F004, it read 555V. This seems some way off the 390V stated in the Supplementary Drive Information you forwarded me. Do you know and could you suggest anything else that could contribute to this? Thanks Stuart [/INST] 555V bus voltage would correspond to a theoretical line voltage of 392V. I think you should look harder at your line in voltage. If you can put a power monitor on it, you might find the voltage is sagging far more than you can read with just a multimeter. Also, what is P001? That is not a valid parameter for PF4M. Did you mean P101 motor name plate voltage? Are you measuring voltage as the motors run up? It sounds to me like your voltage source is very soft and not up to the load. \\n </s>