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Jun 1, 2011 12:00 AM
The answer is not you, but bad power, power outages and power surges to the pressroom — sheetfed or web. With older presses, there are some issues; with newer, more complex presses, these become severe. The cure varies depending on the consistency of power in your area. The first protection you will need for delicate computer equipment is commonly called a “buck booster” to increase voltage in case of low voltage.
In the case of power outages, depending on your needs, you might want a full battery backup (which is expensive) or a manufacturer-supplied small battery backup to be able to save press settings. Many large presses incorporate this feature, but you need to replace the battery every two years or, if you are constantly rebooting, much more often. Power loss while running can be serious and causes a multitude of issues. The first issue, if you are going to be down for some time is washup. An old sheetfed trick is to put motor oil on the rollers and turn the press by hand for one revolution. The ink will never dry, and that is just what you want.
Power surges can be prevented with surge protection on the incoming power. Several printers, to ensure no issues, have placed surge protection on major pieces of equipment. All presses need phase protection. If you lose a phase, you might find that your press will run at speed backwards. This is not good for any press and is a major safety issue.
The key issue is the quality of power reaching your press. Contacting the power company is not an answer. They do not know the quality of power entering your equipment.
The approach I use is to retain an electrical engineer to measure and monitor the power, looking at the grounding of the switch gear on major presses. Keep in mind that driving a 6-ft., 1-inch round copper shaft into the ground does not make for a good ground. A good ground depends on the soil. The quality of ground needs to be measured and, if necessary, a ground field might have to be built. Today's presses are perhaps the most complicated electronics in your plant, in addition to prepress.
Damage that can be traced to electrical malfunction can be overheating of motors and pumps; losing parameters on press and causing mechanical malfunctions; or losing programs.
It is your responsibility as the printer to supply quality power to a major press. It is not the responsibility of the press manufacturer to check your power.
Raymond J. Prince, vice president, Technical Consulting Group, NAPL, is a leading expert in pressroom technical and operational issues. Contact him at (605) 941-1492 or firstname.lastname@example.org. Read more at www.americanprinter.com/how-to/princetip.