I am analyzing a tank (open from top with continuous feed). The level is controlled by the motor (via the VFD). When the VFD is increased from 30% to 50%, it is taking 3 minutes to see the level start going down in the tank. could that be because the VFD settings have been configured to have a 3 minute delay? I believe it is a process delay since it is a huge tank. I would appreciate any feedback.

Thanks

 

Why don't you configure the VFD to show frequency and see if it is responding or if ramps are configured, etc.

Regards
cww

 

I've seen engineers spending hours trying to tune the level control in a big tank. Presume you are measuring the level, comparing it in a controller that sends a speed set point to the Vsd. Try a high gain between 5 and 7 with very little integral action. You will be surprised.

Alternatively you may be using the settings in the VSD. Any reason why you cannot go above 50%?

Lets have your settings please.

 

one way to find out is if u have an analogue input signal coming from the VSD, see if this increases when u increase from 30 to 50% output. If if does then it is a process delay.