Eskay elevators [india] provides various types of drive systems to cater to applications with rated speeds from 0.25 to 2.0 m/sec. These include single speed and variable voltage frequency drives. Selection of an appropriate drive system would depend upon building parameters as well as desired levels of ride comfort and leveling accuracy requirements. Aci: single speed ac drives that start, run and stop at the same speed are vastly used in low-rise buildings with smaller capacity elevators. Acvf: variable voltage variable frequency drives where used, give superior ride quality in terms of smooth acceleration and deceleration and higher leveling accuracy as compared to conventional drives. Advantages:power consumption, overload protection, reduced power factor correction, compensation, reduced motor noise and heat which increases the life of the motor, gearbox and brakes. Hydraulic: hydraulically driven lifts move the lift cabin directly or indirectly by means of a piston and cylinder. It is generally used in low-rise low speed applications and where the advantage of flexible positioning of the machine room and reduced load on the hoist way walls is useful.
