By Clyde V Maughan, president, Maughan Generator Consultants
Cost-containment initiatives over the past several years have encouraged the move to more offsite technical support of outages in powerplants. More recently, Covid-19 travel restrictions have made onsite technical support difficult. Thus, offsite support via video-chat technology has become more common. This has encouraged discussions questioning the adequacy of such offsite support. Recently, a roundtable was convened on this topic on the website of the International Generator Technical Community (IGTC, www.generatortechnicalforum.org).
Participants requested examples of successful specialist remote support. Response was high: six from engineers employed by owner/operators, 36 from consultants. Few of the responses provided information on successful remote support; most were comments on the adequacy of offsite support (sidebar). Owner responders all preferred onsite support but considered remote support as having value.
Remote support. Offsite support can have important benefits to owner/operators. Most importantly, perhaps, is that the convenience of remote support expands the available pool of consultants and the travel money saved can be used for second, possibly third, opinions.
Why is this important? Not all “experts” are experts on all topics; some, in fact, may not be expert at all. But when a generator owner/operator brings an “expert” onsite, that individual likely will be the only expert with whom it will talk. There have been incredible errors made by such “experts.” Here are three examples:
- Unqualified expert. On a routine inspection of a large, modern generator the owner brought in a local “expert” who advised misuse of a common stator winding test. This resulted in a recommendation to rewind, which cost close to $100 million in unnecessary rewind and replacement-power costs.
- OEM engineer error. A 20-yr misunderstanding by OEM engineers of a stator-winding wear mechanism on a line of large generators resulted in rewind and loss-of-generation costs approaching a billion dollars.
- Multiple experts onsite. A very large, very old 4-pole generator with asphalt stator windings was being operated 40 hours annually in a university research laboratory. During a field-out inspection, both an OEM engineer and an independent consultant recommended the following: “Rewind now or risk catastrophic failure.” A consultant with extensive experience on asphalt windings recommended the plant “Hipot the winding at 1.5E, and plan for the next field-out inspection 200 years from now.” The university is following the latter recommendation and avoiding a difficult $3-million rewind—at least for now.
Had the owners in the first two examples been able to tap into a pool of competent consultants and obtain the guidance of a second or third opinion, these very costly situations might have turned out quite differently. Furthermore, the second example illustrates the potential value to owners of having access to a pool of skilled experts when an OEM may be recommending questionable actions.
The availability of talented offsite support will make obtaining the views of multiple consultants convenient and cost effective and will offer the owner ready access to multiple options.
Becoming a generator expert. One of the technical-support issues an owner faces is selection of an appropriate consultant (expert) for the job at hand. How does an “expert” become an expert? In my attempt to understand generators over a 70-yr career, I had the privilege of learning from a dozen incredibly talented industry engineers. Most of what I know I learned listening to these dozen men. Two diverse examples: Dean Harrington (deceased) from an OEM and Jim Timperley from a utility (see safety article later in this issue). Most capable experts have had similar experiences. But today most consultants will not have that privilege, nor in the future is it likely to be even available.
Depending on the properties of the mind of the individual, no amount of training may make a generator expert. Reason: The generator is a highly non-intuitive and extremely complex machine. Unless a person is gifted with a mind that deals well with the non-intuitive and complex, that individual may never become an expert.
As a consultant, 25 years ago I threw caution to the wind and wrote a book on generator design, duties, and deterioration. Using this book I conducted more than 30 two-and-a-half-day seminars for over 1000 attendees. I hoped to provide sufficient information that the user participants would learn enough about the generator to differentiate between an expert and non- expert. I was not trying to make, nor could I make, experts of them in a training course.
What others think about the value of remote support
Engineers with experience in the operation and maintenance of electric generators recently shared their views on the value of remote support during an online forum. Roughly three dozen participants were involved. The editors extracted the thoughts below from what four highly experienced consultants said.
Consultant A completed a “desk review” of an instrument-transformer failure through remote support during the pandemic, which restricted travel. The owners provided onsite inspection observations and photographs. “We were able to coordinate activities by marking up photographs as supplied and requesting additional photographs of specific areas,” he said. This extended the analysis process, but considering three days of travel time would have been required, the overall process was faster than going to the site. Project cost was reduced since there were no travel expenses and the fee for travel time was eliminated.
While larger projects will require onsite inspections, small, less involved, projects can be performed with the excellent communications available today. “We conducted daily conference calls,” Consultant A stated, “but did not use live video since a good internet connection was not available at this location. A live video inspection would have saved time. That should always be considered. Even when travel to the site is required, starting with remote inspections of the conditions will save time overall.”
Consultant B said that Covid-19 travel restrictions made it necessary to conduct rotor-out inspections and interpret EMI tests remotely. With that experience in hand, he believes offsite support may be a promising alternative to onsite visits in the future—at least for some tasks. He thinks OEMs already are moving in this direction to keep personnel safe in less-secure areas of the world.
Consultant B said that while a cell phone and camera are necessary for remote access, analytical success demands more sophisticated tools and proven solutions. Plus, power producers will have to adapt to not having the comfortable onsite presence of specialists. OEMs and third- party vendors will have to change as well, taking responsibilities without their physical presence in powerplants.
Consultant C, a metallurgist, typically is called when something is broken and plant personnel want to know what’s wrong “with this thing.” His work almost always starts out with phone calls, written communication, and photos, lots of photos. The technical process for failure analysis has not changed much in the last half century, he said, but the way you get to a successful conclusion is different in some respects.
What is different:
- Access to good cameras. Plant personnel generally can take the photos required for diagnosis and for explanation of the failure process. A bit of back-and-forth is involved, but it generally works.
- Much better computers. We can now put very clear graphics on photos and figures to explain a failure process or damage process.
- Remote meetings are possible and with a high-quality communications system for conducting meetings, effective tutorials can be presented on a given failure/damage condition. The big benefit is that people can leave the meeting with a clear and unambiguous understanding of what happened.
- Power generation has transitioned from a utility-dominated business with deep experience to one with assets owned by utilities and independent power producers typically having minimal (or no) central-office technical support.
What is not different:
- People on the user side are overloaded and have varying levels of experience—from high to low. This means consultants have to up their game to take less time to explain complicated processes.
- Consultants must make sure that a clear explanation of the analysis process and the basis of the final answers/conclusions/recommendations gets to the right people in the organization.
Consultant D has been involved in generator inspections, failure investigations, and root-cause analyses (RCAs) for nearly half a century. He said that while performing his work remotely is possible in some cases, most engagements require an experienced eye onsite to gather important details often overlooked by the owner/operator.
To perform a proper RCA, for example, one must look at many details not available via a video inspection. Touch and smell are important, too, he noted. Plus, potential problems with language and terminology may impact communications given the international nature of power generation, and clarification may be necessary. Onsite meetings can help in this regard. Remote review of operating data is possible—provided you trust the accuracy of monitoring equipment. You might not have the necessary confidence unless you had eyes on the instrumentation.
When a generator fails, he continued, “what I hear from an initial phone call and photos usually is well off-base with respect to determining the problem and the solution.” A rule of thumb: A good failure investigation requires an extensive onsite inspection, possibly taking a day’s time, to fully assess the failure and the associated unit condition.
A thorough inspection also is likely to find other issues. An example this consultant gave: While investigating a stator winding failure, you might expect to find additional stator problems, rotor problems, air-gap problems, frozen radial dowels, surge-ring cracks, and who knows what else. A video would fall short in fulfilling this mission.
Regarding testing, Consultant D said, “I have given explicit detailed testing procedures via email and phone and received strange results. Further discussions over a month-long period finally proved the directions were not followed and the test invalid.”
On the topic of “becoming a generator expert” the consultant stressed the value of formal education, logical thinking, an innate and high degree of common sense, life-long dedication, and a love of the work. A degree in power engineering, Master’s preferred, is the ideal foundation. No matter how much on-the-job training one has, he continued, knowing power basics, symmetrical components, machine design, dynamics, forces, thermodynamics, basic chemistry, etc, is crucial in developing first-class expertise. It allows one to fit together the pieces of the puzzle.
The future. As the use and value of offsite support expands, there are several factors to consider, some of which are mentioned below:
Remuneration. The average cost for a site visit by a generator consultant today, including travel, hotel, meals, etc, probably is in the neighborhood of $15,000. That number might be reduced by one-third or more by opting for remote access.
Decision between onsite and remote support. I made about 450 onsite visits in my consulting career. Probably half could have been done well offsite with present technology. With better technology and a trained onsite owner’s engineer, three-quarters, or more, of these jobs could have been done well remotely. There are many variables in this “equation” but certainly in the future many onsite visits can and will be replaced with remote assistance. The outcome of the onsite-to-offsite transition will depend a great deal on participation by all affected parties.
Owner support onsite. Remote technical support demands that the owner have a knowledgeable, capable individual onsite. Training for this assignment can be provided by seminars that teach the fundamentals of generator design, deterioration mechanisms, inspection, test, and maintenance—as described earlier.
Capability of consultants. In an offsite world, the true expert will be able to handle many more jobs. A way for owners to share their confidential assessments of individual consultants should be developed so the best engineers will be among those considered for a particular assignment. A secure user-only website, such as that hosted by the Generator Users Group, might be considered for this purpose.
Industry conferences. Online conferences, while not ideal, have major advantages. For example, rather than spending a week away from the plant, the participant spends a couple of days attending the conference from his/her office. Think of the time/cost saving. The reach of an online meeting also is much greater because of favorable economics and convenience. It’s possible, for example, that a meeting of the Generator Users Group could attract a few hundred participants rather than the two or three score it typically hosts.
Technology advances. The ability to transmit high-resolution photographs to experts starting about 20 years ago made offsite analysis practical and jump-started the alternative to onsite evaluation. The same is true of today’s video cameras and video chat systems for offsite support.
Summing up, the evolution in technical support toward offsite support is inevitable. For it to be done well to the maximum benefit of owners, plant and central-office personnel need to take a leadership position in the transition effort. CCJ
Clyde V Maughan retired from active consulting in July 2018 at the age of 92. Today he spends free time sharing unselfishly his extensive knowledge of generators with those seeking advice. The Clyde, as he has come to be known, spent 36 years with GE before “retiring” in 1986 to form his consultancy. Much of the knowledge Maughan acquired during his 70-yr career has been shared with the electric power industry through more than two-score technical papers, more than a dozen CCJ articles, several webinars, his handbook “Maintenance of Turbine-Driven Generators,” dozens of seminars, and other avenues of communication. He also founded the Generator Users Group with help from a few industry associates and contributed significantly to the launch of the International Generator Technical Community.