Getting the Most Out of Your Electric Motor Repair

Even with standards, studies and certifications, there is no guarantee or requirement for repair shops to provide exceptional or reliable electric motor repair.

Mnet 165968 Dem Burn Out Stator Image 1 1

Stator Stripped with Burn-Out oven method. Notice poor condition of stator. Forensic analysis is not possible when all materials are incinerated thus prohibiting root-cause determination.  Even with standards, studies and certifications, there is no guarantee or requirement for repair shops to provide exceptional or reliable electric motor repair.  The few programs that do exist for evaluating motor repair shops are primarily set up for marketing with no teeth to protect the end user.  In all, it is still incumbent upon you to check, verify and select motor repair facilities based upon your expected reliability of the electric motor once it has been returned.  Your analysis should address the following: Will the motor be returned with the expectation of OEM (or better) operational life? How will the motor be analyzed and the failure’s root cause determined? Will the stripping method allow Forensic Analysis, and will my operation experience less downtime post repair? (The real reason you need your motor repaired)

There are motor repair standards that can assist in assuring a good motor repair such as the IEEE Std 1068-2009, “Standard for the Repair and Rewinding of AC Electric Motors in the Petroleum, Chemical and Process Industries,” and associated standards, the ABFMA series for bearings, and NEMA MG-1, “Motors and Generators.”  These provide guidance on the repair process and the IEEE 1068 also outlines responsibilities.  It is necessary that you specify the requirements for the motor repair, so referencing these standards, at the very least, is critical.  Additionally, standards represent the minimum necessary requirements, so tightening up on specifications and adding requirements based upon your needs should be the norm, not the exception.  It then becomes a balance between the cost of the repair and the reliability of the electric motor.

The selection of the repair shop is critical.  Each organization has its own reputation and culture.  If you are dealing with a repair shop that does not maintain cleanliness in its work areas, calibrate its equipment or is focused on fast versus accurate, then you can expect that they will provide that level of work regardless of what you specify. (It’s recommended to tour your repair facility and learn as much as you can – after all it’s your up-time and revenues on the line) 

If you require excellent motor reliability and availability, as well as concise follow up on the potential root-cause of motor failures in order to provide information for internal reliability improvements, then you must partner with a repair shop that already has the culture in-place.  Internal repair processes and methods must allow the capability of performing detailed analysis of motor failures, when required, such as detailed testing forms for measurements and non-burnout stripping methods so that the insulation system can be investigated after coil removal.  While one of the most common processes for coil removal is the burnout oven, which is a convenience for the repair shop, the reduction in electric motor reliability and efficiency in addition to the loss of information from an intact insulation system can have a staggering impact on your bottom line! A repair method such as Dreisilker Electric Motor’s MotorSafe process cleanly strips a motor keeping all insulation components intact.  This allows post stripping forensic evaluation and failure root-cause analysis. The use of OEM materials, and greater than OEM rewinding practices, result in a more reliable motor with increased energy efficiency.

The reliable repair shop will always work with its suppliers to ensure that they are receiving quality materials and be willing to reject sub-standard materials instead of a focus on the least-cost.  The electric motor repair industry operates on tight margins when cost is the primary consideration by the end-user.  The result can be sub-standard materials and the use of parts that should be rejected.

Dreisilker technician re-winding stator post MotorSafe Stripping.  Notice clean condition of stator body and laminations. Proper gauge wiring is used and insulated to better than OEM standards.  The DEM process results in increased motor life, improved reliability and a savings in energy.  Finally, a reliable repair shop will have on-staff technical support that can provide both root-cause and post repair support in order to work with you on solutions.  All too often end-users assume technical competence because a repair shop is involved in electric motors when they may actually only know the function, but not necessarily the engineering nor any of the standards, or advanced, root-cause investigation techniques.

Excellence in repair comes with reputation, the ability to investigate materials by removing them intact, engineering processes, and solid technical support and a cooperative environment with vendors and customers alike.  The culture of a repair shop is determined by the knowledge of their craftsmen and conditions in the work environment, such as cleanliness, safety and pride in such a way that the facility encourages customer visits.

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