text: <s>[INST] Kinetix 5500 Servo Driver H015 FLT S25…PRECHARGE FAILURE Hi, I had two kinetix 5500 servo driver H015 will show FLT S25…PRECHARGE FAILURE error on the drive whenever it being power up with DC 24V & single phase AC 240V simultaneously. I read across the user manual for the power up sequence. It required to provide DC 24V first then wait until it turn to PRECHARGE state only provide the single phase AC 240V. I follow with this method and the error didn't not show & motor show RUNNING state. But I feel quite weird for the machine & driver that need to turn on DC & AC voltage at different time. Anyone meet this issue & any solutions I can deal with this condition so that my panel able to power on the DC & AC at the same time & the servo driver able to run? [/INST] Hello, the power up sequence of the Kinetix 5500 servo drive, as mentioned early on this thread, is clearly documented on Publication Kinetix 5500 Servo Drives User Manual. By design specifications, the Kinetix 5500 servo drive needs to be powered up following that order. After applying the 24V DC control power, the LCD display begins the startup sequence, which includes a self test that requires a few seconds, before the axis state can reach the PRECHARGE state. Is that time when three phase AC power should be applied. If the AC voltage and DC voltage are applied at the same time, the shunt resistor circuitry may not enable at the right time, which could generate these type of nuisance faults. More information about this via this technical note Kinetix 5500 No display or lights, not powering up . \\n </s>