Performance under design and test of the 20500 HP TEAAC synchronous motors for the Shaybah project in the Rub-Al-Khali desert, Saudi Arabia

In July 1998, a large oil company successfully started up the ambitious Shaybah oil production project. The largest motors that were procured for this undertaking had to be designed to operate in one of the most forbidding environments on earth. The project location in the Saudi Arabian Rub-Al-Khali (Empty Quarter) desert experiences daily heat extremes in excess of 50 °C, extensive periods of wind-borne dust, and exposure to relentless solar radiation. Totally enclosed air-to-air cooling (TEAAC) was and continues to be specified for all large motors. The motor standards that were applied during procurement were based upon NEMA MG-1, which clearly stated that for operation in an ambient that exceeds 50 °C, the allowable temperature rise is to be reduced by 20 °C. This paper reviews the performance issues that were raised during design and test in order to meet the requirements of this very difficult TEAAC application. Engineering tradeoffs that had to be thoroughly justified by both the motor manufacturer and the motor user are also highlighted.