DC-SCR or AC-VECTOR - Which way to go?greenspun.com : LUSENET : Elevator Problem Discussion : One Thread
We are in the process of modernizing out 20 year old elevators. Should we rebuild our old DC motors or get new AC motors?
We have a 23 story residential building with 3 passenger and 2 service elevators.
Any advice would be greatly apreciated.
-- Len Greenberg (email@example.com), February 18, 1998
In the industry 20 year old motors are considered new. Do not listen to sales people. I have worked on motors, that perform fine, from the late 19th century. But of course d.c. motors need periodic maintenance, and will not run 20-120 years with out repairs. If your motors were well maintained there is probabally little wrong with them. A basic tune up and brush replacement, plus setting neutral and brush angle plus quartering, would make these motors respond like new. But if you have money to burn, new is always better. D.C. motors require more maintenance and are less economical, and the new vvvf systems give the best ride, if this is an important factor in your conversion. But if you have a 20 year old system that is not up to par,there is an outside problem. Not the equipment.
-- Joe (JMclo30547@aol.com), July 23, 1998.