Users of Explorer series online motor performance monitors from Baker Instrument Co. (www.bakerinst.com) were interviewed about the results they are able to obtain and their experiences with the company. (Those interviewed also use Baker off-line testers, such as its Advanced Winding Analyzer).
The online units connect at the motor control center, breaker or drive to rapidly analyze a running motor and driven system and perform root cause analysis based on voltage level and balance, harmonic and total distortion, rotor cage condition, motor efficiency, effective service factor, overcurrent, operating condition, torque ripple, load history and other factors.
The users’ applications range from 40 hp to 12,000 hp, 480 VAC to 13,200 VAC, primarily three-phase and driving fans, pumps, compressors, conveyors, crushers and mills. One also is monitoring a few 250-VDC pump motors.
Users report receiving early warnings of impending failures tracked to broken rotor bars, contact bounce, load problems in pumps and fans, and faults in new motor specifications, designs and construction. “I also use it for establishing baselines with newly installed equipment,” says Ed Johnson, senior engineering technical support specialist, Progress Energy, Raleigh, N.C. Along with broken rotor bars, Johnson has found voids in cast aluminum rotors and motors supplied with incorrect voltages that didn’t match power supply upgrades.
Remote monitoring is a key benefit. “As a nuclear generating station, we have motors which can’t be monitored via conventional means due to radiation/contamination concerns,” says Harry Smith, component and technology specialist, Limerick Component Maintenance Optimization Group, Limerick Generation Station, Exelon Nuclear, Pottstown, Pa. “The biggest return on investment is that we can now monitor motors located in inaccessible or harsh environments without having to be directly at the motor itself.”
Smith says other Explorer series strong points include, “The amount of information obtained from a test that takes only approximately 2.5 minutes to complete,” and points out that it allows the user to assess variables such as power quality, motor electrical and mechanical condition, and mechanical condition of the driven equipment.
“It’s simple to use,” says Arv Sias, senior engineering technical analyst II, Consumers Power Company, West Olive, Mich. “Diagnostic tests can be accomplished with one instrument instead of multiple meters and recorders.”
Data from off- and online testers can be integrated, a significant benefit according to Johnson. Sias agrees, saying, “All your motor data is in a single database that you control.”
The technology is sophisticated, and while the instrument makes it relatively easy to handle, support and training are important. “Support and service from the company regarding the testers, analysis of the data and troubleshooting has been very good,” says Smith. His questions have been answered “in a timely manner” and Baker has openly accepted and incorporated his suggestions for software improvements.
“Baker didn’t leave me cold when the test equipment was sold,” says Johnson. “They have faithfully supported me with problems with the test equipment as well as with analysis of the data.”
Training is a strong point, with numerous classes and levels offered throughout the year. “Baker personnel also have come onsite to provide specific and custom training for Limerick CMO testing personnel,” says Smith. An annual users’ group meeting gives users the opportunity to share case studies and discuss issues or improvements with Baker personnel.
“Selecting new test equipment is important to keep a predictive maintenance program growing and able to maintain or exceed the expectations for equipment reliability,” says Smith. “Incorporating the Baker AWA and Explorer has allowed us to take the motor testing program to a higher level.”
Sias sums up his experience, “Worth the money. After I had my first Explorer II, within a year I bought another for logistic reasons.”