This case study outlines the upgrade of an existing 30-ton capacity Class E magnet service crane.

Originally sold as a cab controlled static stepless crane with wound rotor motors, the crane had performed well over its first 35 years of service. However, Static Stepless control and wound rotor motors have dramatic negatives in this era of crane design and maintenance. Controls that not only provide a high degree of operational readiness, but give maintenance personnel an advantage with trouble shooting and preventative repairs are a huge asset for cranes used in plant production.

The scope of the project included a structural survey, as well as a mechanical inspection of drums, gearing, couplings, and all wearing items to ensure the crane could function better than new after the modernization was completed.

The goals for this project included:

• Zero injuries or accidents during the work period
• Replace all controls for the crane
• Replace wound rotor motors with invertor duty squirrel cage motors
• Replace all brakes with Thruster brakes
• Replace the entire festoon
• Replace the cab controllers and provide a better ergonomic environment in the cab
• Leave the crane with more operational time, with lower cost of ownership controls and devices

The pictures below are to show the condition of the crane prior to the upgrade.



This picture shows the volume of Static Stepless controls on the catwalk.

This picture shows the general condition of the old P&H controls.

The cab featured old SIR induction masters mounted directly in front of the operator blocking a large portion of his view. The operator chair we were told, was uncomfortable for the operators.

This is a picture of the original HEW wound rotor motors.

Installation in progress, old controls removed from the crane.

Old controls stacked for removal (note: saturation reactors).

New control panel ready for installation.

New Magnetek invertor duty motor with bracket mounted Mondel shoe brake.

Old motors and brakes were removed and existing supports reworked or replaced.

New motor and brake installed, see Avtron encoder to provide feedback for Static Simulation control.

Old festoon was updated with new trolleys and cable.

Completed project in 5 days, with maintenance and operators loving the results.

The results are fantastic, and the crane now provides new crane reliability and the operators love the operation of the crane with an upgraded cab.

Long term, Magnetek variable frequency controls will reduce the number and type of mechanical breakdowns as the motors cannot generate un-needed (additional) torque to crane motions. This will extend wheels, couplings, shafting, and increase gear durability.

Six months after the installation the customer wrote us to express how happy they are with the results. If you have an old crane and want to investigate a modernization instead of a replacement, please call Engineered Lifting Systems or contact us today!