I've NEVER seen an elevator install/ upgrade which permitted outsiders ( non-elevator technicians ) to touch ANY aspect of their sub-system.
That specifically includes phase conversion/ rectification and transformations.
The latest Otis Elevators are entirely dialed into 480 VAC power. When 208Y120 is Service Power -- they install their own step-up transformer.
The much older Otis Elevator, being replaced, used a rotary rectifier: namely a motor-generator set. It'd spool up before the doors would even open.
Until the modern electronic era, only DC motors were considered suitable for traction effect.
Now, step-wise, these are all being replaced by smart AC motors.
BART hauled its old cars off to the factory to be rebuilt with them.
Likewise the entire railroad fleet is being shunted oven to AC.
I wouldn't even consider using a rotary phase converter for elevator duty.
Perhaps you're looking at / thinking of a motor-generator set.
