For electrical contractors and field electricians
If you’ve ever had a motor shut off for no apparent reason, or worried about the real effect of harmonics on your electrical equipment over time, you may have a power quality problem. The growing use of automation, variable frequency drives and other nonlinear loads designed to increase productivity, and energy efficiency have also caused some unexpected consequences for power quality. Often the first sign of a problem is when a system inexplicably goes down or cuts out intermittently.
Such an event can be costly and could pose a safety issue, so more and more organizations are focusing on getting a complete power quality picture of their facilities. In the last few years several new tools have been introduced to help accomplish that, and electrical contractors and field electricians are looking for additional training to understand the complexities of power quality and how to put those tools to the best use.
Professional power quality training in Minneapolis
In the Minneapolis and St. Cloud, Minnesota metropolitan area, electrical professionals are turning to the Minneapolis Electrical Joint Apprenticeship Training Committee (JATC). The Minneapolis JATC is a nonprofit organization jointly sponsored by the Minneapolis Chapter of NECA (National Electrical Contractors Association) and Local Union 292 IBEW (International Brotherhood of Electrical Workers).
Students who attend classes at the JATC include: in-house electricians responsible for maintaining and monitoring commercial, industrial, and municipal buildings; construction electricians who need to assess and monitor power quality on initial commissioning of new buildings or remodels; and service technicians and electricians who provide troubleshooting and/or preventive maintenance services.
“Some of our students are already using power quality analyzers and other preventive maintenance equipment, but they don’t think they’re taking full advantage of all the features and software tools, so they want formal training,” says John Kjome, Technical Instructor at the Minneapolis JATC. “Others want to want to expand their skillset to open up new potential professional opportunities.”
Practical training for the field
Kjome has extensive experience with the needs of field electricians, having worked for 10 years as a journeyman wireman, a service technician, and a maintenance technician on building automation, energy management, and HVAC systems. About half of that time he worked for the city of Minneapolis retrofitting city buildings with new electrical infrastructure, automation, and building maintenance technology. “In that role I became acquainted with some of the Fluke power quality instruments like the 43B single phase power quality analyzer,” says Kjome. “We did a lot of investigations into why things were going wrong and the 43B helped quite a bit.”
His next stint was as building engineer and project manager with a health club organization that operated facilities throughout the Midwest and Texas. That job found him retrofitting the electrical infrastructure in many older buildings. “We ran into a lot of problems with system overloads, shutdowns, misfires, and equipment failures,” says Kjome. During those experiences he saw a growing need in the field for a better understanding of power quality and electrical safety issues.
Kjome began teaching evening and weekend electrical code classes at JATC in 2007, covering topics like motors, grounding and bonding, and power quality. After a year and a half he moved into teaching full time with a curriculum he developed on HVAC, building automation, and refrigeration.
From zero to proficient in 16 hours
In spring 2011 Kjome introduced a two-level Power Quality course sequence, which consists of two eight-hour courses. “Our power quality courses can take students from no power quality experience or knowledge, to understanding power quality phenomena and confidently troubleshooting those issues in the field,” says Kjome.
Level 1 covers power quality phenomena - transients, dips, swells, interruptions, and harmonics - and identifies what you need to look for and why. “Electricians in the field need to understand all of that before they can understand how to mitigate those problems.” says Kjome.
At the end of Level 1, students are introduced to a variety of instruments used to monitor and troubleshoot power quality issues. Those instruments include the Fluke 43B Single Phase Power Quality Analyzer, 435 Series II Power Quality and Energy Analyzer, CNX™ 3000 Wireless Multimeter, voltage and current modules, and the Fluke 87V Industrial Multimeter, as well as tools from other companies.
Gaining hands-on proficiency
In Level 2 of the Power Quality course, students spend much more time with the instruments. They learn how to use and read them in a variety of situations, and how to extract, analyze, and report on the data collected. In the lab sessions each student is furnished with a laptop computer that is networked to Kjome’s computer. Kjome’s computer is connected to a 435 that is hooked up to the school’s electrical service to log data such as power factor, total volt-amps, system harmonics, spikes, sags, and to calculate financial loss due to those situations.
John Kjome, Technical Instructor at the Minneapolis JATC, uses the Fluke 435-II to perform a power quality audit of the training facility.
That logging process has produced some interesting details about the JATC facility. “We found a lot of power sags, which we’re following up on to determine whether they are cause for concern with any of our equipment,” says Kjome. In addition, the school has a power factor correction capacitor bank, and the 435-II found that the facility has been over-correcting its power factor during the winter months so that it has a leading power factor. This is due to the lack of cooling needed in the building throughout the winter. Conversations with the utilities and equipment manufacturers will determine if switching the bank is necessary to avoid damage or penalties.
To show students how to analyze harmonics, Kjome takes the 435 to the motors lab, where a bank of variable frequency drives (VFDs) are hooked up to a group of motors. “We hook up the 435 on the line side of the convertors on the VFDs and it shows how much of the harmonics from the VFDs is feeding back onto the line,” says Kjome.
Kjome also pairs the 435 with CNX™ 3000 wireless tools. “We set up the 435-II on the service entrance or main service panel and attach the CNX modules to watch at other points so that we can correlate problems,” says Kjome. “If I do a load study on a panel with the CNX tools on one feeder and I see some abnormalities or dips, I can go back to my 435-II at the service entrance or main service panel and see if anything happened there at the same time. If nothing shows up on the 435-II, I can I look further downstream on the feeder.”
Improved power quality equals cost savings
Kjome sees the demand for power quality analysis growing dramatically over the next several years because of its potential for saving money on: