Application Guide

63-706247

VFD Features Used

— Auto restart.

— Over speed.

— Over torque.

— Stall prevention.

— Analog or digital control.

— Forward/reverse for clearing blockages.

— Variable torque control.

IMPORTANT

Ensure that the VFD can handle the breakaway toque of the load. It may be necessary to select one size larger VFD

than the motor to achieve this.

Elevators (See Fig. 56)

1 2 3 4 5 6 7 8

Floor 6

1 2 3 4 5 6 7 8

Floor 7

Elevator Motor

Elevator Gearbox

Elevator Brake

Floor 8

Inverter

Landing

Switch

RST

MONPARREFBTNS

RUNREADYFAULT

Honeywel

Fig. 56. Elevator application.

Application Description

As there are governing regulations covering equipment used in the transportation of people, this application requires the

involvement of an organization already involved in elevator maintenance and installation. Small elevators tend to use single or

two speed motors directly connected to the elevator gearbox. When the car approaches the landing a switch is made and the

elevator motor is disengaged from the power supply and the car is brought to a halt by use of a brake. If the motor is 2 speed

then a second speed phase is selected before the motor is disengaged from the power. This form of control is temperamental

and the stopping accuracy (unpredictable) due to the temp of the brake, load and moisture, all affecting the accuracy of

stopping.