motor hums, then the belt smells like a decision

After the VFD install the motor sometimes hums for a second on start and the belt smells if I do it twice. Not every start. Mostly cold mornings. Butte, so that is a lot of mornings.

A hum then a release is often the belt grabbing a pulley that's slightly glazed, or the accel on the drive set so low the motor sits at a stall. Smell is rubber, not electrical, if it's the belt. What's the accel time, and does the smell happen if you start it with the belt off?

Accel was eight seconds because I was being gentle. Belt off, no smell, just a motor. I set accel to three and dressed the glaze off the pulley with a stone. Two cold starts, no smell. I'll complain again if it comes back. That's the arrangement.