Control panel design: Easier access
The industrial control panel, containing network equipment and programmable automation controllers, is central to operations. Having access to these controls on a routine basis is required for production management and manufacturing execution system (MES). However, accessing this equipment requires precautions necessary for safety and regulatory compliance.
One of the issues with control panel access is the risk of arc flash. Arc flash occurs when there is a release of energy caused by an electric arc. This arc flash creates a blast that within a few milliseconds reaches several thousand degrees Celsius and in turn causes severe burns and often death.
OSHA, in hand with NFPA 70E standards, requires anyone opening control cabinets to have training and wear protective gear. The requirements also include planning and assessment of hazard potential as well as area marking to include protective boundaries and warning labels. Needless to say, these efforts add up to a lot of time and money.
An alternative involves the use of a pass-through to access the automation controllers. Panel interface connectors (PICs) or access ports enable a user to test and maintain equipment without opening the panel. This arc mitigation solution alleviates the need for personal protection equipment (PPE) and the need for a trained electrician to de-energize the system.
Panel interface connectors mount to the outside of the control panel. A typical PIC will contain a power supply (single, duplex, GFCI) and one or more connectors commonly used for programmable devices. These connectors include D-Sub, RJ45/Ethernet, USB, DeviceNet, and others. Often there will be a 3-amp reset as well.
While there are situations when a system needs to be shut down for full access, using a PIC saves time and money and allows for testing and maintenance in an energized state. Making adjustments to equipment and network systems and having the ability to monitor changes in short order is a huge time savings.
– Lynne Keener is marketing coordinator at Mencom. Edited by Mark T. Hoske, content manager, Control Engineering.
Founded in 1987, Mencom Corporation, located in Oakwood, Ga., provides industrial electrical connectors. Mencom is among the last remaining manufacturers of U.S.-made electrical cordsets.