By Ron Marshall for the Compressed Air Challenge
A metal foundry had a disastrous fire that took down part of their plant. Buried under the rubble were their new air compressors, installed only a few months earlier. Miraculously, their compressor supplier was able to refurbish the units, shine them up, and get them running like new.
During the rebuilding of the damaged part of the plant, the air compressors in a second part of the building were maxed out because they had to take up the slack. This area was far from the main power transformers and the feed wires had a significant voltage loss, which caused problems at the compressors. Because these units were now heavily loaded there were many nuisance trips.
Recognizing the problem as undersized electrical distribution equipment, the electrical company working on their plant repair offered to upgrade some components to solve the problem. After the work was done on the weekend, an old compressor was restarted and placed on full load. Within minutes, production staff started noticing a strange noise. The noise got louder and smoke started rising from the compressor. In a few more minutes, the compressor was so hot it was uncomfortable to stand beside. Staff pushed the emergency stop button and called for help.
Service personnel attempted to investigate but the machine was too hot to touch. It took four hours to cool the unit down for troubleshooting. After a long investigation, it was discovered that the machine had been running backward! This is fatal to lubricated screw compressors. The personnel doing the electrical work had mixed up the phases on the compressor input supply. Running the compressor backward had seized the machine, causing irreparable damage to the compression element.
A silver lining in this cloud was that the damaged compressor was the oldest and least efficient unit of the bunch. Now a new, more efficient compressor can be purchased, courtesy of the electrical contractor’s insurance company.
Learn more about compressors in our next Compressed Air Challenge seminar in your area. Visit www.compressedairchallenge.org for more information.
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