Control Panel Design: 60% Less Space
The winner of the 2009 Control Engineering panel design award is CP Packaging of Appleton, WI. The company’s design for a plant-floor machine control panel reduces space on the machine, provides easy access for maintenance, reduces costs, and saves build-out and installation time.
In the winning video describing the entry, CP Packaging’s Ray Buchko Jr., vice president of operations, explains that the rugged design of the panel meets the needs of the VisionPak Horizontal Form-Fill-Seal Vacuum packaging machine. “In the environment where these machines are used, the panel also had to be durable enough to withstand high-pressure washdown, so designing for sanitation was also important,” Buchko says.
|Viewers who commented on the CP Packaging VisionPak Control Panel video cited enclosure access as a strong feature of this winning entry.|
The design removed the servo drives from the cabinet and distributed them onto the machine. “That change saved about 60% in control cabinet space, and 30% or more in wiring costs,” Buchko says. Because the Bosch Rexroth integrated motors and drives are connected by one cable (instead of the previously required 12), adding more drives won’t change cabinet size.
The servo power supply is mounted sideways to reduce the cabinet depth. The integrated drive motor technology saves panel space and cabling, up to 1.5 square feet on a 6-8 axis machine. Less energy is used overall because integrated motor drive regenerates electricity.
Buchko calls the panel enclosure (32 x 36 in.) unique, because it swings out for maintenance and doubles as a machine guard for areas behind it. A finished back panel is bolted into a water-tight, high-pressure-washdown stainless steel enclosure that swivels out from the machine. With small size and low weight, the panel for the seven-axis machine can be lifted into place by one person, Buchko says. Mounting the panel on the machine (instead of remotely) reduces possible points of failure and saves time on wiring and installation, helping reduce startup to less than 24 hours, as opposed to several days.
Inside the panel
In addition to the team at CP Packaging, Buchko also credits Marty Paschke of Machine Control Specialists, Little Chute, WI, for “initial layout of the panel and component locations to minimize the size of the panel and still maintain separation of low and high voltage wire points” and control components. On top there’s the control wiring: main controller, I/O modules with spring cage terminal connections, and other controllers. On the bottom is the high-voltage wiring. In the middle, terminal blocks connect above and below using insulation displacement technology to save time and keep the integrity of the landing points to avoid shorting. In addition, DIN rails are used as much as possible to help save time.
|In the CP Packaging control panel, controls and I/O modules are on top, terminal blocks in the middle, and high-voltage components on the bottom.|
Wade Savage of CMA/Flodyne/Hydradyne, Brookfield, WI, “helped source the components that provide the flexibility we require to manufacture custom machines with a single enclosure. The design allows us to stock panels in house, using common components without modifications, and mount one on a machine in less than a day.”
Simpler design means panel assembly is possible in hours rather than days, with easier maintenance and troubleshooting. Other design elements facilitate machine functionality:
Heat zones can be modified with a 14-zone Phoenix Contact temperature controller without changing components; Phoenix power supply footprint saved up to 40% space. Contactors and pushbuttons are from Moeller (part of Eaton);
Banner Engineering supplied safety control relay, eliminating 18 wire terminal points and I/O points with Ethernet-based communications;
Because of the food-processing environment, the machine, main panel, and touchscreen withstand high-pressure wash downs, 34-38° F as often as every shift;
Three communications protocols are used: An Ethernet protocol goes from the controller to the touchscreen and outside the machine for monitoring. Profibus allows use of one cable on the machine without wire bundles or continue runs. (In food processing plants, any wire has to be run and cabled separately, rather than bundled, to avoid trapping bacteria.) SERCOS goes over fiber from the controller to the integrated motor/drive for high-speed motion control communications.
Each machine is wired to accept 3-phase, 480 V power from one drop and to supply power to auxiliary equipment nearby (vacuum pumps, primarily), via quick connects, tying in communications through the touchscreen interface.
“Test runs start three hours after installation. That’s important,” Buchko says, “since food plants are sanitary, startup means downtime for everything else in the room. We’re using the same design principle on another machine, which should give us similar advantages, including a better price point. It’s a cost-sensitive market.”
|More information on the CP Packaging VisionPak Horizontal Form-Fill-Seal Vacuum packaging machine is available at www.cppac.com/go/visionpak .|
|Mark T. Hoske is editor in chief of Control Engineering ( www.controleng.com ). Email: MHoske@cfemedia.com .|
Panel design voting criteria result in useful tutorials
Judging criteria for the control panel contest videos focused on how well the videos explained the following:
The thought process for determining the layout of components, both interior and exterior component mounting techniques;
Wire and cable termination techniques;
How consistency is maintained from one person to another in component mounting and wiring practices;
Door work (mounting, labeling and wiring of devices on an enclosure door, or other exterior surfaces);
Methods for insertion of completed panels into enclosures;
Methods for maintaining cleanliness and protection of the enclosure and components; and
“That’s a lot to pack into a panel design video in five minutes,” noted Control Engineering ’s David Greenfield, editorial director. “While all six continue to garner interest, voters clearly put CP Packaging on top.”