Archives for November 2017

Not Just an In-Rush

You have heard us many times discussing the effectiveness of an In-Rush/Start-Up test as a critical piece of information in assessing a variety of potential anomalies in components such as the stator, rotor, power, and load. Capturing the In-Rush/Start-Up during the start of an electric motor allows the capture of data when the motor is under extreme stress and more likely to expose anomalies.

Less often discussed is that the In-Rush/Start-Up test can also be instrumental in identifying mechanical and load related defects during routine scheduled testing. The enveloping feature of the In-Rush/Start-Up test taken during steady state gives a direct look into the load fluctuations of the motor being tested. Having a baseline of the expected load characteristics for a motor provides a very easy comparison for early identification of even subtle changes in these load characteristics which could be early indications of developing faults.

To view examples of these tests and see them successfully applied in the identification of a developing pump failure visit our website case study at: http://www.pdma.com/webinars/Pump_Case_Study/Pump_Case_Study.mp4

Decatur Industrial Field Service Team and Repair Technicians Save Alloy Steel Manufacturer Close to $100,000

Connecting the 750HP motor side of the generator

Click on the pictures to enlarge.

Decatur Industrial Electric recently received an emergency field service request from a steel industry customer to troubleshoot the controls and inspect a 750HP, 900 RPM M-G set that would not start.

During inspection we found that the generator portion of the M-G set had serious issues with the interpole insulation. Between the core iron and the coils, the core insulation had completely disintegrated and turned to powder. Additionally, the line leads on the motor portion of the unit were oil soaked and swollen. It was determined that the unit needed to be removed and repaired at Decatur Industrial because it was impossible to properly test the unit in its current condition.

Upon arrival at our shop, we completely reconditioned the M-G set, which included removal of all the interpole coils, reinsulation, and a VPI treatment. We also rewired the DC internal connection and releaded the AC motor stator. Finally, we were able to properly troubleshoot the control problem and repair the faulty contacts.

Although we were unable to initially troubleshoot the controls due to the deteriorating insulation on the generator side of the unit, we saved the customer the cost of a complete M-G set rebuild which can cost upwards of $200,000. They paid less than half of that amount for our repair.

Save the Date: March 15, 2018, EASA Workshop

Class: Root Cause: Winding & Rotor Failures / Root Cause: Bearing & Shaft Failures
Download the Flyer

Cost: $300 per person or $275 per person if 2+ attendees from same company
Time: 8 AM to 5 PM CST (lunch will be provided)
Where: Decatur Industrial Electric / 1650 E. Garfield Ave. / Decatur, IL 62526

One of the most important factors to consider when repairing motors is to understand why they failed. This seminar will focus on common as well as unusual types of failures broken down by components.This class is intended for anyone interested in understanding motor failures & addressing the root cause of failure rather than the symptom.

RSVP Options:

Tell your D.I.E. Account Manager to “Sign me up!”
call 217-428-6621 and ask for Kelli

Taught by: Jim Bryan, EASA Instructor
Jim Bryan is a technical support specialist with the Electrical Apparatus Service Association (EASA). Before joining EASA, Bryan worked for more than 20 years at Emerson Motor Company (Nidec Corporation) in St. Louis