Electricity and Control July 2023

DRIVES, MOTORS + SWITCHGEAR

Crane system upgrade In industrial facilities today it is not uncommon to find overhead cranes that are more than 80 years old still in operation. However, this gives rise to a range of complex operating issues as well as concerns around safety and reliability.This case study sets out how crane control specialist, MH Automation International and crane parts supplier, CP Automation worked together to upgrade the crane control equipment of an overhead travelling crane operating at a south Wales steelworks.

O verhead cranes have been used since the first industrial revolution to move heavy and oversized objects in a range of applications. The original equipment manufacturers (OEMs) of the cranes designed the structural components of these material handling powerhouses to withstand mechanical forces far greater than those encountered in day-to-day operations. However, with the slow speeds and limited ratings of early cranes, old equipment may not be able to meet the needs of modern material handling applications. Manufacturing facilities today need to maintain a constant flow of materials to remain competitive and any disruption can result in production losses and associated costs, which can escalate by the hour. Site managers are therefore always looking to minimise downtime and maintenance expenses as well as energy costs. Where older equipment is not adequate to meet current material handling demands, the operator has three options to improve the system’s performance: invest in a new crane, refurbish a used crane, or upgrade the existing one. Rather than scrapping an outdated crane which is still structurally sound, it is often more cost-effective to upgrade and modify the control system of an existing crane to meet current operational and safety needs. A leading UK steel

Joseph Booth & Bros equipment is well-known in the steel industry. Although the company is no longer in operation, it merged with several other well-known crane manufacturers in the 1900s, creating the newly established Wellman Booth name. Today, this brand is part of the Clarke Chapman group of companies, which still counts companies in the nuclear and steel industries as some of its biggest customers. Improved control The crane that was due for upgrade has three motions: hoisting, cross travel and long travel, driven by DC Series wound electric motors. The crane was used to move product at the steelworks where about 400 000 tonnes of tin, chrome and polymer coated steels are manufactured per year for the packaging industries. MH Automation set about designing a new main hoist drive panel to control the primary hoist mechanism provided for lifting and lowering the rated load. In addition, the long travel and cross travel motions were upgraded to provide safe and effective location of the gantry and trolley. A regenerative power module (RPM) was provided for the regeneration of braking power into the mains supply to improve efficiency. This assisted the company with its drive for sustainability. The equipment had to have a high specification for environmental conditions, as steelworks are particularly dusty environments. In addition, protection against water ingress was required in this application. The crane control specialist called on CP Automation’s experienced engineers to assist with the specification. They recommended the Magnetek Omnipulse™ DDC Series 2 to convert the crane’s outdated dc controls to state-of-the-art efficient DDC (digital dc) Series 2 drives. Employing semiconductor technology, which provides more advanced control of motor speed and torque than costly and inefficient DCCP control, the new drive control system improved control and safety dramatically. (Direct current constant potential (DCCP) control technology dates back to the late 1800s.) An ideal ‘drop-in’ replacement for traditional electro mechanical control, the DDC Series 2 was also chosen for its compact modular design. Its footprint is 33% smaller than typical motor controls and it is nearly 50% smaller by volume than typical contactor controls, reducing its space requirements and weight on the crane. John Mitchell, Global Sales & Marketing Director at CP

manufacturing company chose to follow this route in upgrading several cranes across its operat ing sites. In the latest of four similar retrofit projects spanning a ten-year peri od, the steelworks sought to increase the reliability, safety and productivi ty of its obsolete legacy equipment. The company turned to MH Automation, a Cardiff-based specialist in electrical crane control system upgrades and re furbishments, to under take this upgrade project on a Joseph Booth & Bros ten-tonne electric over head crane.

The crane in action.

12 Electricity + Control JULY 2023