This diagram shows how the Hot Oil Over Protector approach works.
Time to talk some ‘HOOPS'. No, not basketball hoops. The NCAA Final Four is a done deal, and the NBA has another month before it heads into its playoffs.

The ‘HOOPS' here is Hot Oil Over Protector, a proprietary technology designed to minimize the time it takes to detect a thermal fault condition and react to it in order to protect a compressor.

"HOOP technology is something entirely new," said Rick Izor, executive vice president for Bristol Compressors, which has developed the technology for Benchmark scroll compressors. "Rather than relying on hot gas, HOOP uses hot oil to quickly trip the motor protector and protect against a compressor failure."

Izor said the technology was developed to deal with thermal fault conditions that can lead to galling or damaging of the scroll wraps. "The longer it takes to trip the motor, the more likely there will be permanent damage or a compressor failure," he said.

The HOOP approach was created to deal with that possibility in a different way from the more familiar hot gas method.


"When high temperatures are detected in a typical scroll compressor, hot gas is released from the high-pressure side to the low-pressure side, where the motor is located," said Izor. "The gas heats up a bimetal protector on the motor causing it to trip. Eventually the motor cools down and the compressor restarts. This cycle will be repeated until the system is serviced or the compressor fails."


"When high temperatures are detected in a Benchmark scroll, HOOP technology channels hot oil directly onto the motor's bi-metal protector, which trips the motor quicker than hot gas. The amount of time the scroll is operating in thermal fault conditions can be minimized and so is the potential damage caused."

The idea is to make "it less likely to experience a compressor failure," he said.

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Publication date: 04/03/2006