Steel recoiler safety controlled

It’s often a requirement of many manufacturing processes to have the operators become directly involved in the machine action at the unloading point, either to unload or secure the outbound product. Unfortunately, the outfeed sections of most processes are notoriously dangerous, so in reality we should be striving to remove the operators from the area at all times.

The ability to combine safety and productivity is highly evolved these days but many still incorrectly think it gets harder and harder as machines become ever more complex and automated. Recently, however, Marcus Blaik of AM Electrical managed to prove to his customer, Coil Coaters of Arndell Park in Sydney, that indeed blending safety and productivity can be done easily and cost effectively when you use the right solution.

Coil Coaters is a OneSteel company that, just as its name suggests, specialises in the coating of steel coils for use in guttering and many other architectural applications. Once the coil has been coated it is rewound into coils on large recoilers ready for dispatch.

History had shown that the recoiling step in the coating process had a number of hazards, most notably entrapment of the nearby operators in the coil. Although no injuries had been reported, OneSteel’s risk assessment procedures had identified this as a high priority to guard against.

A concept was devised to remove the operator from the recoil machine area by installing an automated roller door. However, the operator still needed access to secure the completed roll and to extract the coil for shipment. This meant that the operator needed to enter the hazardous area and have the ability to jog the recoiler so he could strap and remove the coil easily.

AM Electrical’s Blaik was asked to supply a solution that allowed access and control, yet did not expose the operators to the identified hazards. Blaik’s first phone call was to Pilz Safe Automation, and after scoping the project, in consultation with Derrin Drew from Pilz, a solution using the PNOZ Multi with speed monitoring module was put in place.

“The PNOZ Multi gave me so much flexibility to set zero speed detection, jog speed and overspeed that the solution actually became really simple,” said Marcus. “All we needed to do was wire in the encoder feedback in the Multi and the rest was done in the configurator.”
Interfacing into the existing Siemens S7 PLC on site was done with safe outputs from the PNOZ Multi which would not allow the PLC to go into full speed, and if the PLC failed and an overspeed condition was detected, the Multi would remove power from the large recoiler drives directly. In combination with PSEN Code gate switches mounted on the recoiler entry door, the Multi safely guaranteed that the operator could never access the machine while at full speed, and yet allowed the operator to safely jog the machine so he could remove the coil for shipment.

“The PNOZ Multi was straightforward to install and program, and had all the functionality to complete this application straight from the box — in fact, with one Multi and one speed monitor we were able to independently monitor two recoilers, which saved us a great deal of money and time.”

Also impressed with the solution was Arthur Crampton, operations manager for Coil Coaters. “It just works! We run these machines 96 hours at a stretch without stopping, so we don’t have the luxury of taking a recoiler offline to troubleshoot.”

Pilz Australia Industrial Automation
www.pilz.com.au