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Analyzer connects to equipment to assess power quality

Issue: January 2018

MachineSense LLC in August introduced its Power Analyzer electrical line monitoring system to provide detailed power quality and energy consumption information for connected equipment such as extruders, injection molding machines, auxiliary equipment and other types of devices.

The Power Analyzer electrical line monitoring system

The system features cloud-based analytics and easy-to-understand dashboard gauges that require no advanced training or expertise. Historical trends track usage patterns, identify damaging power anomalies and compare energy consumption between devices.

President and COO Jim Zinski and Fred Eichhorn, GM of the controls group for sister company Novatec Inc., discussed the new technology at the Extrusion 2017 conference, sponsored by Plastics Technology and Gardner Business Media Inc., Oct. 18-20, in Charlotte, N.C.

“This is a very fast-growing field, one that’s being built on new and emerging technologies, but it’s rooted in time-tested engineering and scientific principles,” Zinski said.

Power quality issues cost the plastics industry $9.6 billion annually, Eichhorn said, citing statistics from the Electric Power Research Institute. About 80 percent of power quality issues are created inside industrial facilities, Eichhorn said. The good news is that most causes of power problems can be diagnosed and corrected. The bad news, he said, is problems are frequently misunderstood or ignored.

Symptoms of poor power quality included burned-out motor windings, burned transformer cores, malfunctioning electronic devices and blown capacitors on variable-frequency drives (VFDs), Eichhorn said. “Repeated or premature failures of electrical components can be a symptom of poor power quality rather than poor part quality or faulty machine design,” he said.

Power quality issues are a growing problem for a variety of reasons:
• The increased use of VFDs, which can create harmonics — distortions in the power supply that can result in heat buildup in some devices and premature failure.
• The proliferation of electronic devices with DC power supplies that convert AC power to DC. These can create a non-linear load that causes harmonics.
• Plant expansions that can result in unbalanced electrical phases.

Power quality issues can be grouped into four main types:
• Voltage sag, which is a momentary decrease in voltage of anywhere from 10 percent to 90 percent and lasting for less than one minute. Causes include supply fluctuations, motor starts and cycling machinery. Consequences include excess current loads and tripped fuses or breakers.
• Voltage swell, which is a momentary increase in voltage ranging from 110 percent to 180 percent of normal voltage. It can be caused by a reaction to sag, motor stops and cycling machinery. It results in the breakdown of components connected to the power supply.
• Voltage imbalance, which is caused by a variation of values between voltage phases on a multi-phase electrical system. Typically, the difference between the highest and the lowest voltages ranges from 0.5 percent to 2.5 percent, but variations should not exceed 4 percent. Consequences include overheating and failure of motors, heater banks and transformers.
• Harmonics, which occur when there are non-linear loads on an electrical system that do not use the power evenly through the entire waveform. This can be caused by loads switching on and off faster than the fundamental frequency, which creates distorted partial waveforms with unconsumed energy. Harmonics can cause motors or transformers to overheat and break down.

Cloud-based analytics and dashboard gauges

It can be difficult to diagnose and understand the causes of a variety of power quality problems, which makes the Power Analyzer a valuable tool for plastics processors and other businesses that might not have electrical engineers on staff.

Traditional tools for diagnosing power quality issues include oscilloscopes, current meters and harmonic spectra analyzers. However, the equipment has limitations. For example, employees cannot constantly monitor the power supply to catch power quality issues that occur only sporadically. In addition, it takes resources and time to collect data. The equipment for monitoring power quality can be expensive, costing $10,000 or more, and it often requires additional training or third-party expertise.

By comparison, Power Analyzer has low investment and integration costs, Zinski said. The cost for hardware, including current sensors, voltage probes, data-collection equipment and predictive software, is $1,195 per device monitored for a 100-amp system and $1,295 per device for a 300-amp system. The price includes six months of access to analysis and plans for corrective action that are hosted in the cloud and a data subscription. After six months, a customer pays subscription prices.

Users receive a dashboard readout on a PC or smartphone. The software uses status color codes — green for normal, yellow for warning and red for alarm — to indicate whether there are any power quality issues. The software can detect current or voltage imbalance; voltage sag or swell; voltage and current harmonic distortion; machine utilization, including the amount of time a piece of equipment is operating; heater bank analytics, including whether a heater element may have gone out in a multi-element heater box; and motor analytics, including predictions on the deterioration of motor bearings and stator windings.

Eichhorn described how Power Analyzer helped a film extruder that had frequent power shortages that caused two extrusion lines to slow down and water cooling units to shut down.

A Power Analyzer installed on an extruder identified a drop in the voltage supplied to the plant every day at about 2:30 a.m. The film producer worked with the power company to determine that the problem stemmed from a new industrial process being used at a nearby factory. The process started daily at 2:30 a.m. and put a high demand on the electrical supply line, creating intermittent power shortages. The power company solved the problem by increasing amp service to the extrusion facility, Eichhorn said.

MachineSense is selling its system as separate equipment for manufacturers in the plastics and other industries, but plans on partnering with Novatec to offer it preinstalled on Novatec dryers.

Bruce Geiselman, senior staff reporter


For more information

MachineSense LLC,
Baltimore, 443-457-1165, www.machinesense.com

Novatec Inc.,
Baltimore, 410-789-4811, www.novatec.com