Pacific Blue Engineering (PBE), a CSIA member systems integrator and certified TÜV functional safety engineering team that provides turnkey control system integration solutions, machine safety services, staff augmentation, and more. A client hired us:
A. Reducing the probability of near misses and accidents over the life of machines to acceptable levels.
B. Improving OEE and operator productivity.
C. Reducing CAPEX spend by upgrading existing versus buying new pallet wrapper.
The client was required to reduce the chances of near misses and accidents by upgrading existing guarding that was not compliant and upgrade the safety controls to Performance Level D. The client’s fear that production would be slowed by the additional safety control changes did not materialize. In fact, OEE and productivity improved due to operators being able to safely and quickly access the machine to perform critical tasks. Regarding installation and commission, the client had the option either to purchase an entirely new pallet wrapper or to upgrade the existing machine. The latter option was selected since it was determined to be a more cost-effective CAPEX solution.
The upgrade of the controls on the pallet wrappers required the upgrade of an obsolete SLC PLC to the Compact Guard 5380 series. Nine AC drives were replaced with Power Flex 523, Power Flex 70, and Power Flex 4 drives to the Power Flex 525 platform with Safe Torque-Off inputs. Existing door switches were replaced with new guard locking switches. The pneumatic circuits were modified to incorporate a safety valve, and output devices were upgraded to safety contactors and safety relays. The existing camel View 600 was replaced with a Panel View Plus 7 standard and, to provide light curtain muting, safety light curtains with four photo eyes were added. A critical addition implemented was the addition of four requests for entry push buttons and four E-Stops.
In the initial phases of the project several issues were fixed, issues that were inherent to the machine but never addressed by the client. For example, the Pallet Station strategy was modified to improve efficiency, features being added to reduce the time taken by an operator to reset the machine while maintaining safety compliance. Safety measures were added that improved productivity such as the requests for entry stations that allowed operators to reset the machine without walking around the entire machine line. In short, controls and improvements were introduced to reduce operator tasks and improve the overall efficiency of the pallet lines, while maintaining safety standards and performance levels.
The project had several challenges. For example, certain safety valves, although advertised as such, did not have all that was necessary to provide true performance level reliability. It, therefore, became necessary to thoroughly research the components to verify that requirements were met in terms of redundancy and fault detection.
For future considerations, PBE offered the client different types of field IO reporting technology. Such changes could significantly reduce commissioning time and risk, as well as providing the ability to add other devices to leverage smart sensing technology. It was also recommended that the client install safety PLCs to replace the standard PLCs currently in use.