Belt Requirements on VFD Motor

[302Hugo]

I am trying to size out belts for a 400 HP driver at 1800rpm and I am using the typical V belt selector graph. At this setting the choice would be 5VX belts, however this driver is also on a VFD with 3:1 turndown. So according to the graph once you slow down the RPMs lower than about 1500, it puts it into the 8V range. Any recommendations on which belts I should use? I would assume I should use the 5VX belts since they will provide the best option for operating at the higher rpms?

 

[ccfowler]

Take care to leave plenty of margin in the belt sizing due to the VFD. They can introduce some potentially nasty torque fluctuations. Make sure that you fully understand your VFD's characteristics under all conditions.

Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.