Will Altistart 48 work when motor is in regeneration mode.
In steady state and regenerative mode the motor is in hypersynchrone so the
energy is sent back to the main, no problems.
The problem can be if you have a low current (close to the PHF threshold) and during the transition between motor/generator state then the residual current can
be only the magnetizing current and decrease under the PHF threshold.
No energy is transfered during deceleration.