I'll throw in a wild card, here. The more recent trend is to have 3 phase VFDs with smaller capacitor banks, because three phase has low ripple voltage even when not filtered.
I designed one with a 50 uF film capacitor as the bus capacitor. It worked very well. Of course, the client then revealed (for the first time) that they also wanted a version for single phase input.... for that we had to add an external capacitor bank, involving a delay and extra cost since it was not revealed until the design was completed.
Sucj small capacitors have fairly actual low inrush, and if they are film capacitors, the allowed inrush current of the capacitor can be quite high, so there may be no need for any special protection.
Your Yaskawa may be older, and likely does have a big bank of capacitors.
I designed one with a 50 uF film capacitor as the bus capacitor. It worked very well. Of course, the client then revealed (for the first time) that they also wanted a version for single phase input.... for that we had to add an external capacitor bank, involving a delay and extra cost since it was not revealed until the design was completed.
Sucj small capacitors have fairly actual low inrush, and if they are film capacitors, the allowed inrush current of the capacitor can be quite high, so there may be no need for any special protection.
Your Yaskawa may be older, and likely does have a big bank of capacitors.
