Why repair an electric motor?

Posted on: January 24th, 2013 by admin No Comments

Why repair an electric motor?

The largest segment of the Electric Utilities market is the power consumed by electric motors. Electric motors drive everything from the electric screwdriver in your tool kit to the large refrigeration compressors that provide air conditioning for our largest buildings and plants.
Although the average electric motor will see a usable life of twenty years or more, many will see an early demise due to their operating conditions, lack of maintenance, improper application, improper repair or defects. When this happens the owner/operator must decide whether to replace or repair the motor.
Many factors have to be considered when deciding between repair and replacement. Certainly the cost to replace a motor is important. Often, however, the availability of a suitable replacement and the cost of repairing the “old” motor are just as important. With rising utility cost, the efficiency rating of the “old” motor and it’s replacement often out weigh repair/replacement cost. A large motor can cost an industrial user more to operate than he invested to purchase the motor in the first place. Looking closely at operational cost can sometimes yield tremendous savings when replacing a motor.
When a motor fails, a professional repair facility can help with the decision-making process. Often, a quick “bench test” (usually at no cost to the owner) can often help the motor repair shop determine whether or not a repair is economically feasible. If the decision is made to further examine the motor, a complete disassembly and assessment is typical. This in-depth examination often will disclose the root-cause of the failure. For example, if a motor winding has failed, an in-depth examination may disclose the reason for the failure. The professional repair shop can often determine the cause of a winding or bearing failure, thus avoiding a repeat failure.
Many in-house maintenance personnel are interested in one thing – getting the machine back “on-line” to avoid expensive down-time. They may not be capable of determining that a loss of voltage on one of three phases caused a winding failure. If a replacement motor is installed without determining and “curing” the root-cause of the failure the new motor may fail before anyone realizes that the motor failure was the “effect” and not the cause of the failure.
By the same token, a home-owner may know that the capacitor on his irrigation pump has failed. He may not be able to determine why it failed. If the owner replaces the capacitor it may not last more than a few seconds.
Repairing electric motors is more than replacing bearings. It requires the use of sometimes sophisticated diagnostic equipment as well as relying on years of knowledge to determine why a failure occurred, then repairing the motor to suit the owner and the application. Finally, testing of the motor under controlled in-shop conditions can assure the owner/operator that his motor is once again capable of doing the job for which it was designed.

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