S.W. POWER COMP.'S POWER TRIPPED OFF AT ""POTASH JUNCTION"". THE TRANSFORMER HAD TO BE REPLACED. THE POWER WAS RESTORED AT 9:30P.M. THE CREWS WERETAKEN OUT OF THE MINE. WHILE THE ELECTRICAL POWE R WAS OFF NO WORK WAS DONE IN THE MINE. AFTER THE POWER WAS RESTORED, TESTS WERE MADE WITH BOTH HOISTS AND PRODUCTION RESUMED.