According to the US Department of Energy, motor-driven equipment accounts for 64% of the electric consumption in the commercial and industrial sectors. This is understandable as most commercial and industrial operations are using a variety of motor-driven equipment, from conveyors to crushers, saws, compressors, pumps, and drive fans.
Because of the prevalence of electric motor usage, regular maintenance and inspections from professionals are necessary to keep things running smoothly. However, there are other factors that may lead to problems with your electric motor as well. Here are some additional problems to consider:
Transient Voltage
Transient voltage can come from multiple sources located inside or outside a commercial facility. And it can be difficult to identify the source of the transient voltage because their symptoms are rarely the same.
Factors such as fluctuations in adjacent loads can produce transient voltages on distribution systems. Their frequency and wavelengths may vary, which when coupled with poor wiring can cause insulation breakdown in motor windings. Over time, this leads to early motor failure, which in turn can cause you headaches and unplanned downtime.
Misaligned Motors
Misalignment happens when the drive shaft doesn’t line up with the load, which causes the motor to vibrate and over time, erode. Misalignment on motors is one of the common causes of motor failure, and it can generally be traced to an improper setup.
Electrical Erosion
Electric erosion takes place when a stray current uses a bearing for its path to ground. It is caused most often by fast-switching variable frequency drives, unshielded power cables, or asymmetry within the motor’s magnetic circuit.
Once electrical arc damage to the bearing starts, rising noise levels, increased heat, excessive vibrations, and weaker effectiveness of the motor’s bearing lubricant will reduce the bearing service’s life. This increased heat can be observed via thermal imaging quite easily. The amount of damage varies based on its duration and the amount of energy directed at the bearing. The result, however, mostly stays the same, with the bearing’s rollers and raceways being damaged, the lubricant quickly degrading, and the bearing failing prematurely.
Harmonic Distortion
Harmonic distortion is caused by unwanted sources of high-frequency AC currents or voltages. These unwanted currents provide excess energy to the windings and continue to circulate within them. As a result, energy is lost as heat, continuing to damage the windings over time. This lost heat can also be detected using thermal imaging and infrared scans.
Sigma Current
When currents are uncontrolled within a motor, this activity is known as sigma currents. It is caused by the following factors:
- Conductor inductance and capacitance
- The frequency signal
- The level of voltage
The rise in sigma currents causes the windings to heat and, in turn, causes the motor to be compromised. This issue needs to be fixed quickly or it may result in frequently triggering breakers and possibly even starting electrical fires. If you are experiencing electric motor issues, you may want to consider getting having the motor inspected and all the electrical wiring checked.
Skyline electric is a commercial electrical contractor that can help builders and contractors such as yourself get rid of old and poorly maintained electrical systems and install new and updated systems in their place. We also run a fully equipped and professional electrical motor repair shop.
We have been helping residential and commercial buildings, skyscrapers, offices, schools, hospitals, and a variety of other facilities with their electrical systems and would be glad to do the same for you! Get in touch with us today for a FREE quote, or to have your existing system analyzed by professionals!
