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Application Notes:
The Cost of Poor Power Quality |
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Productivity is the key to survival in today's globally competitive environment. When you think about the basic inputs to production - time, labor, and materials - you can see there isn't much room for optimization. You have 24 hours per day, labor is costly, and you don't have much choice in materials. Thus, every company must use automation to gain more output from the same inputs - or perish.
So, we rely on automation, which in turn relies on clean power. Power quality problems can cause processes and equipment to malfunction or shut down. And the consequences can range from excessive energy costs to complete work stoppage. Obviously, power quality is critical.
The interdependence of various systems adds layers of complexity to this issue. Your computers are fine, but the network is down - so nobody can book a flight or file an expense report. The process is operating correctly, but the HVAC has shut down and production must stop. Mission-critical systems exist throughout the facility and throughout the enterprise - power quality problems can bring any one of these to a grinding halt at any time. And that will usually be the worst possible time.
Where do power quality problems come from? Most originate inside the facility. They may be due to problems with:
- Installation - improper grounding, improper routing, or undersized distribution.
- Operation - equipment operated outside of design parameters.
- Mitigation - improper shielding or lack of power factor correction.
- Maintenance - deteriorated cable insulation or grounding connections.
Even perfectly installed and maintained equipment in a perfectly designed facility can introduce power quality problems as it ages.
Power quality problems can also originate from outside the facility. We live with the threat of unpredictable outages, voltage sags, and power surges. Obviously, there's a cost here. How do you quantify it?
Measuring Power Quality CostsPower quality problems make their effects felt in three general areas: downtime, equipment problems, and energy costs.
DowntimeTo quantify system downtime costs, you need to know two things:
- The revenue per hour your system produces.
- The costs of production.
Also, consider the business process.
Equipment ProblemsExact costs are hard to quantify, because you are dealing with many variables. To get the correct answers, you need to do two things:
- Troubleshoot to the root cause.
- Determine the actual costs.
Energy CostsTo reduce your power bill, you need to record consumption patterns and adjust the system and load timing to reduce one or more of the following:
- Actual power (kWh) usage.
- Power factor penalties.
- A peak demand charge structure.
You can reduce power usage, avoid power factor penalties and reduce peak demand charges. By eliminating the power quality problems, you reduce the size of the peak demands and the base from which they start. By using load management, you control when specific equipment operates and thus how the loads "stack on top of each other."
Saving PQ DollarsYou've tallied up the costs of poor power quality. Now, you need to know how to eliminate those costs. The following steps will get you there.
- Examine design.
- Comply with standards.
- Examine power protection.
- Get baseline test data on all loads.
- Question mitigation
- Review maintenance practices.
- Use monitoring.
At this point, you need to determine the costs of prevention and remediation - and then compare those to the costs of poor power quality. This comparison will allow you to justify the investment needed to fix the power quality problems. Because this should be an ongoing effort, use the right tools so you can do your own power quality testing and monitoring rather than outsourcing it. Today, it's surprisingly affordable - and it will always cost less than downtime.
Click here to download the full pdf: The Cost of Poor Power Quality » | |