A: This frequency jump from 0 to a specific value is typically a parameter setting issue rather than a fault. Reset the parameters and restart to see if it resolves. Typically, parameter P01.01 sets the initial frequency during inverter startup, causing the inverter to start at the frequency specified in P01.01. Alternatively, parameters P08.08 and P08.09 may be configured to bypass undesired frequency levels and jump directly to the target frequency. These parameters can all cause the inverter frequency to jump abruptly.