JIMMIE wrote:
On Sep 11, 2:58 pm, ml wrote:
hi


Elevator motors are DC, in the old one the DC was supplied by a motor/
generator combination, The new ones get their DC from a huge SMPS and
they can be electrically noisy. They can also induce harmonics into
the electrical system that UPSs dont like at all. It is my
understanding the elevator rehab project where I work has been put on
hold for that reason.

Jimmie

Modern elevators use AC induction motors with a variable speed drive.