ABB/NEMA GP100 Series General Purpose Motors
ABB General Purpose low voltage NEMA motors are designed and built to operate in a variety of commercial and industrial environments. These motors are design to meet or exceed the NEMA Premium® efficiency (MG1 Table 12.12). A wide selection of options makes them suitable for a variety of applications.
On this list you will find:
A Decatur Industrial customer had back-to-back motor failures on a 300HP boiler fan. This was a critical application and the failures greatly impacted plant production.
Issues often occurred during startup from maintenance outages while the fan was being energized or a short time later when the unit had reached speed.
We needed to do two things: On-site evaluation + motor disassembly and RCFA in shop.
The motor was found to have failed due to moisture condensing on the windings. When the units were offline for maintenance, they failed to have the proper accessories to prevent moisture. D.I.E. installed silicone space heaters on the winding.
On-site inspection found a steam leak in an adjacent area that vented into the room where the motor was sitting idle during the outages. The customer needed to the change the venting to send the energy outside the building for the steam to be released.
Lastly, we reviewed the motor for opportunities to improve performance. The OEM winding design was not optimal as it produced high voltage stresses within the stator. D.I.E. redesigned the winding for better performance and increased reliability. The new winding has:
Shantel Rogers, a former student at Eisenhower High School and Richland Community College, has received a $1,000 scholarship to help cover educational related expenses for the upcoming school year. She will be studying business at Millikin University.
“Winning this scholarship means confirmation, for me.” Rogers went on to add, “Life has a way of switching our paths in unexpected ways. In these transitional periods we can doubt the work we’re putting in and feel it’s in vain. Winning this scholarship has shown me that no matter what may be in front of me, if I stay true to myself and keep pushing forward, things will work for my good.”
Her long term career goals have changed since the onset of COVID 19. Initially her goal was to climb the corporate ladder in a good company. However, COVID and the changes it brought to the workspace sparked her entrepreneurial spirit. Her goal after college is to build her own company that great people want to climb the corporate ladder at.
The Claud Thompson Decatur Industrial Electric Scholarship
This scholarship assists students seeking a career in business through the Tabor School of Business (PACE included) at Millikin University or students pursuing engineering technology degrees at Richland Community College. Additional criteria online includes financial need and students who are self-driven and leadership-oriented with a record of community service. High school seniors and college students may apply for the scholarship on the Community Foundation of Macon County website at www.endowdecatur.org.
To find out more about our founder, click here.
Some technicians may have a near photographic memory and can remember details about the motor and environment they tested a week ago without confusing it with the other 25 motors they have tested since. However, for the rest of us mere mortals it is critical to add a test note at the end of a test to identify anything that may benefit the analysis or troubleshooting of this motor now or in the future. A technician may modify a normal test routine for troubleshooting, questionable test data, etc… The reasons for the unusual test data are unknown, unless there is a note attached to the asset that explains the anomaly. Analysts may be looking at cyclic anomalies thinking that a problem exists and a possible overhaul may be required when the root cause of the anomaly might be an environmental temperature change or a process transition or just a bad set of data due to a connection problem. The eyes and ears of the technician can not be over rated. A simple conversation between the technician and the operator can be worth so much to the analyst, but if that piece of information stays in the head of the technician and never makes it to the test notes, then the analyst is left in the dark. For you MCEGold® users the Message Center offers a centralized location for test notes and messages to be added to an asset. It also auto records any changes to the asset health condition with the opportunity to add the reasons why. By popular demand the pop up asking if you want to add a note following a test has returned, making it even easier to add test notes.
Contributed to PdMA
Do you know the number of allowed starts in one hour. For NEMA A and B motors operating within allowed variations of voltage and frequency, there are actually three categories related to starts, but two of those categories are fairly easy to apply. For this tip we will be focusing on the two that are easy to apply:
Let’s start with two general thumb rules:
A 10 HP 2 pole motor is allowed 6.2 starts per hour with a 92 seconds off time before the next start. A 10 HP 6 pole motor is allowed 14.2 starts per hour with a 41 seconds off time before the next start. That’s more than twice the number of starts and less than half the off time when going from a 2 pole to a 6 pole motor. For a larger 250 HP 2 pole motor you are only allowed 1.8 starts per hour with a 1000 seconds off time. Change that to a 250 HP 6 pole motor and you get 4.2 starts per hour with a 440 seconds off time. According to NEMA (National Electrical Manufacturer Association), the inertia of the load, motor HP, and speed (# of poles) are the determining variables. The extreme heating that occurs during startup demands that you stay within these start guidelines to prevent premature damage and reduced life expectancy for your electric motors. So not only should you track the lifetime starts of your electric motor, but also track the number of starts and start times per hour.
