text: <s>[INST] PowerFlex400 Driv e not going to Zero Hz I have (3) 40hp PF400 drives that are running fans. The speed references are two digital inputs from a selector switch, High, Off & Low. The Off position has no function. When the selector is in Off there is no speed reference, however, the drive does not stop running, but continues to idle between 19 & 20 Hz. When either of the inputs is on the drive accelerates to the preset that is assigned to that input. The HIM displays Decelerating while the drive is idling but the Output Frequency never goes below 19Hz. The terminals for STOP (1) and START (2) are connected to 24V (11). Terminal (5) is SPEED1 and Terminal (6) is SPEED 2. Any thoughts on why these drives are not fully decelerating to zero Hz when speed reference is removed would be appreciated. [/INST] If you're using 2 inputs to run predefined frequencies, define the third frequency as both inputs off, with a 0 hz preset. You're using IN1 and IN2 for speed presets, right? T051 and T051 parameters are set to 8 (preset frequency)? If that's the case, then IN1 = 0, IN2 = 0, the drive uses A143 for frequency source (Preset Freq 0) IN1 = 1, IN2 = 0, the drive uses A144 for frequency source (Preset Freq 1) IN1 = 0, IN2 = 1, the drive uses A145 for frequency source (Preset Freq 2) Set A143 to 0 hz. Look at page 3-35 (91 of the PDF) in the user's manual: http://literature.rockwellautomation.com/idc/groups/literature/documents/um/22c-um001_-en-p.pdf \\n </s>