Repair Bulletin Detail

The Importance of Restoring Servo Drives to OEM Specs

The objective of any servo drive repair should be to fully restore the drive to its original OEM performance levels.

A drive that has been properly tuned to factory specifications will demonstrate significant improvement in performance, can operate up to maximum power across a wider temperature range, and will experience a prolonged life.

Can’t All Repair Shops Adjust Drives to Factory Specifications?

Most servo repair shops unfortunately fail to deliver up to the OEM standard. To accomplish this requires them to have complete access to the drive’s original documentation, schematic diagrams, and factory-issued test fixtures during the repair process.

MSI has access to all these genuine factory-issued test fixtures and other materials, as a benefit for being the only factory-authorized repair center for these legacy drive brands: Kollmorgen, Pacific Scientific, IDC, Superior Electric, API, and TAE.

The Role of PC Board Schematics

Servo drives are set at the factory and their adjustment requires very specific knowledge of involved circuits and tuning procedures.  Such adjustments cannot be done without the original documentation and manufacturer-issued PC board schematic diagrams.

Lacking this information, unauthorized repair companies must resort to merely guessing what components are truly defective.

We tend to argue that you really shouldn’t have someone playing the guessing game as they attempt to diagnose issues with important circuits that affect drive performance.

Two particularly critical circuits include: the current sensor circuit, which provides current feedback for each motor output while regulating the drive’s power stage, and; the resolver feedback circuit, responsible for feeding the motor’s velocity/acceleration/position data to microprocessor.

Our Test Fixtures Helped Manufacture Your Drives

MSI’s test fixtures came to us directly from the factory, after having served in the actual manufacture of legacy drive equipment. Each individual fixture was created to test the exact design and specifications of a select line of servo drives.
The Trouble with Standard Bench Tests

While it’s possible to bench test a servo drive without such specialized fixtures, those tests fail to address the unique characteristics of the drive.  Critical functions and drive capabilities can be easily overlooked, leading to less-than-optimum performance.

We hope that in the future you won’t settle for a repair that merely gets your drive “back up and running.” Instead, rely on MSI’s factory test fixtures, schematics and parts to get your drive running efficiently at its intended OEM standard.

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