Industrial Motors / Preventive Maintenance / Asset Management System

What to look for in a motor repair shop

Get to know the people and the equipment you’re entrusting your motors’ health to.

By Timothy Thomas, Hibbs ElectroMechanical Inc.

When planning and executing a predictive maintenance strategy, the issue most often overlooked by maintenance supervisors and even their superiors is the quality and capabilities of the motor shops that repair their equipment. The shop that will be responsible for helping you maintain a successful and efficient facility is of utmost importance.

Motor repair facilities are not all alike, and many issues can affect the quality of repairs and rewind services that shops provide. Most reputable motor repair facilities will encourage your visit, so go unannounced and pay attention to how you are received. Before you go, make a checklist of what you want to look for and which questions you want to ask. Remember, the safe and effective operation of your plants and factories is dependent upon your electromechanical repair facility and its adherence to universally accepted standards.

One important issue to consider is the shop’s affiliation with EASA, the Electrical Apparatus Service Association. EASA is the watchdog whose goal is to provide end users with assurance that they are dealing with a dependable and reputable vendor. EASA offers invaluable resources for its members and provides a forum for thought leadership as well as a showcase for equipment manufacturers at conferences.

More-advanced shops will have an EASA-certified designation beyond being an EASA member. Certification is costly to a facility, but third-party evaluations help ensure that a shop has proper equipment and skilled technicians and complies with established best practices regarding electromechanical repairs. 

Next, be sure the shop monitors itself with a written quality-control program and a supervised and tracked safety agenda. The practice of maintaining a corrective action/preventive action agenda ensures that even minor infractions are documented and action is taken to prevent similar issues from occurring in the future. Office personnel, such as human resources and IT team members, add costs to the overhead, but their contribution to maintaining the high standards of an EASA-certified shop are invaluable.

Quality repair facilities will also monitor themselves by being ISO-certified. The International Organization for Standardization sets standards for numerous types of businesses; ISO 9001 is the international standard specifying requirements for a quality management system (QMS). Businesses use the standard to demonstrate their ability to consistently provide products and services that meet customer and regulatory requirements. 

The repair facility should have the ability to conduct root-cause analysis when damaged equipment is examined. Root-cause analysis (RCA) is hugely valuable when a shop is providing diagnostic recommendations to a customer to help the client avoid a similar issue in the future. The responsibility of RCA is to identify minute details as well as recurring problem areas that eventually lead to machine failure and to assist the customer in providing necessary changes and additions to their process.  

Maintaining a full-time dedicated field-service team is imperative for ensuring customer support. Having the ability to respond quickly to emergency needs as well as provide normal removal and reinstallation of equipment completes the portfolio of a well-equipped industrial solutions provider. Find out whether the shop offers specialized services such as cryogenic cleaning, thermography and laser alignment.

The shop should be prepared to handle emergency repairs and provide pickup and delivery with vehicles of adequate size. Be sure your shop has an emergency contact or operates with three shifts so that you can be confident that someone always will be available if a problem arises. A dedicated sales representative should be available 24/7 to keep you updated and respond to emergency situations with customer-oriented intensity. 

A state-of-the-art motor repair facility will have its own complete machine shop with skilled machinists, eliminating the need to outsource machine work. Your motor shop should be capable of repairing your entire machine, including pumps, gearboxes, fans and blowers. Some progressive shops will even have specialized equipment, such as 3D printers, to facilitate the manufacture of parts that may be obsolete or unavailable. Water jets and CNC machines are not usually found in motor-repair facilities, but they are invaluable when specialty parts are required. Having a well-equipped machine shop on the premises saves time, ensures quality, and helps eliminate the risk of miscommunication.

Check out the facility’s test equipment. Motor shops must be able to perform the proper electrical and mechanical tests and conform to all industry-accepted standards. A shop should offer surge and high-potential testing of the windings with modern test equipment following EASA and IEEE standards for electrical testing and mechanical tolerances. Core loss testing should be documented before and after any heating cycles, including bake-out and burn-out procedures. Excessive or improper heating can damage cores, which will result in lost efficiency and will lead to early failure. You should expect to receive computer-generated reports of findings before, during, and after repairs; these reports should include digital images.

Does the shop have all of its measuring and test equipment examined and certified annually by a third-party calibration vendor? Every “tool” should be recertified annually and documented by a qualified service provider.

Be sure the shop has the proper equipment to handle motors of various sizes and the other equipment they will see from you. Overhead cranes, forklifts and rotor-toters are essential for safe handling of motors and components. Temperature-controlled bakeout and burnout ovens protect laminations from damage than can occur with excessive or uneven heating.

A VPI process is imperative for medium- and high-voltage motors. The VPI process helps make sure that varnish becomes impregnated throughout the windings, and shops will always have sacrificial coils cured along with the stator so that success can be verified. VPI equipment is expensive and requires constant, precise attention to the condition of the varnish. A tank of varnish for a large VPI reservoir can easily cost upward of $100,000.

Proper balancing equipment capable of handling the largest rotors is vital to the repair process. Precision balancing will extend the life and efficiency of motors and other equipment. Efficiency is a major issue; a small reduction in efficiency can result in huge energy costs as well a shortened motor life expectancy.

Can and do they load-test repaired and rewound motors? Load testing and trim balancing helps ensure the final product is ready to go back into service.

All rewind components and bearings should be kept in a clean dry area away from wash and paint booths. The shop should be clean, neat, and open with aisles and walkways clear and identified. Work benches should be sturdy with davit and overhead crane and forklift access.

Does the motor shop have an environmentally controlled “clean room” for rewinding large medium- and high-voltage motors? Clean rooms protect the stator and coils from airborne dust and debris for an optimally effective rewind.

A significant warranty program should be offered, and being a member in good standing at the local Better Business Bureau should be expected. Successful shops will be an active member of their local community and support the local infrastructure, as through work with fire and police departments.

Perhaps the most important attribute of any quality repair facility is its people. Technicians, mechanics, and winders should be highly skilled and experienced. They should be trained, retrained, and updated on a routine basis. The sharing of “tribal knowledge” with newcomers should be not only encouraged but expected.

Get to know shop personnel and be sure that they understand and adhere to your test specifications. You can learn a lot by listening to how people talk about their facility, their managers, and their peers. Good shops retain good people, so ask the winders and mechanics how long they have worked there. Good people stay where they are comfortable and treated well, and so it goes that good management is surrounded by good people. Managers who encourage and inspire their personnel and those who give employees an opportunity to be expressive promote successful teamwork.

In summary, you want a repair facility that is more than a motor shop. You want a shop that can solve your problems and assist you in preventing future issues by providing failure analysis reports on failed equipment and by monitoring your machinery—not only motors—with the aid of experienced technicians. The shop should be able to diagnose marginal issues and remedy potential problems before they create major failures. Structural, environmental and load-related issues may be minor problems on their own, but together they can pose a major threat. Slight misalignment, minor imbalance, some voltage imbalance, and near-full operating load conditions are all negligible, but combined they can cause the machine to be inefficient and shorten its useful life.

Visit your motor repair facility periodically to let team members there know that you are interested in maintaining a close relationship and ensure that they remain capable of performing top-quality work. Most shops will welcome your visit and even encourage you to share your thoughts and feedback. Remember, the continued success of your operation depends profoundly on the quality of their work.