Cause : Pulse-by-pulse Current limit comes when load is too heavy or locked-rotor occurs on motor or the AC drive power class is small. 

"Err40" fault in inovance MD290 drive indicate "Current limit". This means drive is used to limit the maximum current drawn by the motor during acceleration and deceleration. 

1. Reduce load or check motor and mechanical conditions.
2. Replace a drive of larger power class.