Don't Forget the 5th

Mon, 09/18/2017 - 15:35 -- Decatur Industr...

In an AC Induction motor the rotor turns slower than the rotating magnetic field in the stator. This differential rotation loosely referred to as slip can be easily seen in a current spectrum by an elevated pole pass frequency (Fp) peak equal to the number of poles times the slip. The basic analysis concept is to use the amplitude variations of this peak to identify and trend defects in the rotor condition. The higher the amplitude of the Fp, the higher the severity of a possible rotor defect. However, it is important to remember that rotor condition is not the only thing that can affect the Fp amplitude. Machine train load fluctuations can often match the Fp creating a false indication of a rotor anomaly through an elevated Fp. An easy way to isolate the elevated Fp to either a mechanical or electrical source is to evaluate the 5th harmonic frequency peak in the same current spectrum. The 5th harmonic is not fooled by a mechanical load fluctuation and can greatly increase the confidence of the analyst in making the right call on a possible rotor anomaly.
 
To see more details on the 5th harmonic and other rotor analysis techniques visit the PdMA YouTube channel at:
 https://www.youtube.com/watch?v=P4XIYg-695A&list=PLjgXwy4LaY3rMI2MNKer7SxDA50n9LMSa&index=6

September Employee Spotlight: Mitch Duckworth, Assembly

Fri, 09/08/2017 - 08:20 -- Decatur Industr...

Mitch is one of our newest employees at Decatur Industrial Electric and is already an important contributing member of our team. Mitch came to us from a cleaning and restoration company where he served as Restoration Technician. 

His current responsibilities at D.I.E. include assembling motors and prepping parts for assembly. He hopes to continue to learn more about every facet of the business as well as learn different positions and the associated skills. 

Mitch and his wife Amanda live in Decatur and have three young sons. When he isn’t at work Mitch serves as Cub Scout den leader and a Little League baseball coach.  

Claud Thompson Scholarship Awarded for the 2017-18 School Year

Thu, 08/31/2017 - 09:15 -- Decatur Industr...

We wish to congratulate Matthew Kurecki, a graduate of St. Teresa High School and a current Richland Community College student, on being selected for the Claud Thompson Decatur Industrial Electric Scholarship for the 2017-2018 school year.
 
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.
 

Failure to Start? What's Next?

Tue, 08/08/2017 - 11:12 -- Decatur Industr...

Your motor fails to start. What immediate actions do you take when a motor trips on start-up? From a reliability standpoint a variety of possibilities and questions come to mind that may help you decide which direction to take. Was it an instantaneous trip on In-Rush or a time delay trip later in the Start-Up? If instantaneous, is it a stator fault or a nuisance trip? If it's a delayed trip, is it load driven or a rotor anomaly? Oh, and how many times did the operator try to start the motor? Just clamping on an ammeter to see what the current reading is when it trips will not give you the whole story. Looking at the trend of your RMS envelop current signal and comparing it to the raw time domain of the current is ideal.Access to these values and plots, along with previously recorded In-Rush/Start-Up tests will give you the information necessary to make the right decisions for a quick return to productivity.

To see a detailed case study on a critical motor failing to start go to:https://www.youtube.com/watch?v=fMDbhdLDu4o

 

Thanks to our friends at PdMA for this tip.

Welcome Joe Wagner, Reliability Specialist

Mon, 08/07/2017 - 13:57 -- Decatur Industr...
Joe Wagner

 
We are pleased to announce that Joe Wagner has joined the Company as an Outside Sales Reliability Specialist based in Decatur.  Joe comes to us after spending the last 22 years in the construction industry, most recently serving as a Superintendent for A-Lert Construction in Decatur. Joe will work with current and prospective customers in a variety of industries that we serve. Connect with Joe on LinkedIn. 

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