Power Distribution and Management

Why a power quality audit is as important as an energy audit

In today’s marketplace, much confusion exists surrounding the issues of power quality and energy waste. On one hand, owners of commercial, residential, and industrial buildings are bearing the high cost of an ongoing stream of power quality and energy waste issues. Electrical power outages and power-related downtime issues, for instance, cost U.S. businesses $80 billion a year, with 70% to 80% of power disturbances originating inside facilities. On the other hand, many users seem to revert to a crisis-only reaction mode in responding to power quality problems.

We at AZZO, a Schneider Electric Master-level Critical Power EcoXpert, witness many of these power-related cost generation issues in the field. In most cases, we find that power system end users aren’t always sure where to start when dealing with what seem too often to be intermittent power problems. Many turn to organizations like ours to help them detect power quality issues. However, oftentimes they ask us to perform an energy audit when what they really require is a power quality audit.

power quality audits

The difference between energy audits and power quality audits

Let’s take a minute to explain how energy audits and power quality audits differ. Energy audits are designed to assess energy consumption inside a particular facility. Such audits focus on kilowatts, which is how much energy is being consumed at any one point in time, and kilowatt-hours, which is how much energy is being consumed over time. These are figures that appear on a typical utility bill. An energy consumption audit tells you how much energy you’re consuming and when, but these audits won’t necessarily tell you why you are consuming so much energy. The energy audit is a useful first step for reducing energy consumption because it helps to establish a baseline for “normal” operation, from which consumption reduction strategies and improvement targets can be set.

A power quality audit, on the other hand, focuses on the condition of the electricity that is flowing through the building’s electrical distribution system as it gets used. The audit measures how modern-day devices such as computers, LED lighting, high-efficiency variable frequency drives, and control motors are impacting the performance of the power distribution system. In many cases, all these devices create harmonics due to their power supplies. These harmonics (which are currents that can overload wiring creating heat and, in extreme cases, fire) distort the sine waves of the power moving across the system. This “dirty power” then affects the quality and the condition of the electricity within the facility, which, in turn, causes heating on circuits, failure of motors, and/or failures of drives.

Simply put, if a manufacturing site, for example, regularly spends time, money, and resources replacing motors, variable frequency drives, and other control equipment, then the site is likely experiencing a harmonic distortion problem.

Industrial sites aren’t the only buildings subject to harmonics. Any buildings where electronics with power supplies exist are at risk. This includes water treatment plants, hospitals, office buildings, as well as elementary schools and colleges, just to name a few.

Symptoms of harmonics include electrical gremlins that often find users expressing frustrations like “We don’t know why that circuit breaker keeps tripping,” or “We can’t understand why this UPS keeps dropping offline.”

Fortunately, these are all issues that can be addressed and resolved. But the solution often requires experts with specialized filtering equipment that can get beyond just identifying the symptoms of the problem.

Finding the root cause of the harmonics problem

Harmonics and electrical distribution system problems cannot be identified with the naked eye. The process involves installing specialized power quality detection equipment on the power distribution system. This equipment can be either be temporarily or permanently installed depending on the need. Then, once the monitoring begins, careful evaluation by power quality engineers of the data that is recorded can take place.

If harmonics problems are detected, a filtering mechanism may be required. One solution, the Schneider Electric AccuSine Plus harmonic filter, is especially effective at neutralizing the harmful effects of harmonics. AccuSine filters, display the sine waves of the three phases of power flowing through the systems and illustrate the level of harmonic distortion. Once the filtering part of the mechanism is turned on, the sine waves revert to a normal, smooth s-shaped wave that oscillates above and below zero. This filtering process immediately corrects the existing harmonic.

Clean sine wave

Desired clean sine wave

Unwanted harmonic distortion

Unwanted harmonic distortion

For more information about power quality

When power quality problems such as harmonics and voltage spike and sags get in the way of building operational efficiency, expenses quickly rise. A power quality audit ensures that building owners achieve the most out of the energy their buildings consume. To learn how power quality audits can help your business avoid unnecessary power-quality related costs and risks, access our AZZO power quality services and the Schneider Electric web pages.

Global100 Schneider Electric has been recognized as the world’s most sustainable corporation in 2021 by Corporate Knights Global 100 Index.

EcoXperts are the enablers of Buildings of the Future

The EcoXpert Partner Program is unique in its industry and made up of a best-in-class global ecosystem of expertise. Trained and certified by Schneider Electric, EcoXperts are the implementation arms of EcoStruxure and Wiser all over the world.

Buildings of the Future is about delivering solutions for the sustainable, resilient, hyper-efficient, and people-centric buildings that our customers need. For our EcoXpert partners, this unveils immense growth opportunity through the transition to end-to-end portfolio sales that will resolve our customers’ most critical needs. For our shared customers, this means that together with our EcoXpert partners, we will drive the building industry transformation and help our customers survive and thrive today – and tomorrow.

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