Drive Failures Expose Larger Issues

300 HP Variable Frequency Drive


BSC Industries, Inc. provided six large variable frequency drives to a new wood pellet facility along with a number of conveyors. Within a few months of start up, a 300 hp drive failed for an unknown cause and shut down one of two production lines. The drive vendor shipped a replacement overnight, covering the failure under warranty.

A few months later, a 250 hp drive caught fire, again shutting down one line. The vendor again shipped a replacement that was successfully installed. Not more than a  few weeks later, a 200 hp drive failed, again causing a line to go down.

Testing field strength of VFD fan output cable above drive.

At this point, the customer was ready to cease doing business with BSC Industries and even threatened to back charge for lost production.

Knowing that a 50% failure rate is unheard of, and standing by the quality of the drives, BSC Industries hired Enerdoor to visit the facility to offer their expertise on the cause of the drive failures.

Using their test instruments (like the hand-held probe in the image to the left) Enerdoor uncovered extremely poor wiring practices used during the initial plant wiring. For example, signal wiring was adjacent to power wiring, causing stray current to send false signals to the controls. These operating inconsistencies were caused by a lack of industrial installation experience on the part of the contractor and would not have been discovered without the experience of Enderdoor and their technician.

Poor wiring in cable cabinet under VFD fan.

Enerdoor provided a detailed recommendation list on what needed to be fixed. Four electricians with heavy industrial experience were hired to re-wire the areas causing the failures.

Once the recommendations were followed, the problems disappeared and the drives continue to meet the quality and performance standards of both the customer and BSC Industries.

BSC Industries provides products and services aimed at increasing your efficiency and reducing downtime. We don’t believe in simply fulfilling orders, but rather, becoming a partner and resource to our customers to ensure they are receiving high quality products that are doing the job to meet and exceed their goals.

Contact us with new project requirements or old projects that aren’t meeting your expectations.