The NHMFL 105 mm wide bore 900 MHz NMR magnet and protection system were tested in an open bucket cryostat as a qualification test of the integrated system for the first time. The relevant aspects of the superconducting magnet configuration and bucket test operation are discussed. The unique voltage spike and magnet quench behavior are described. A discussion is provided to substantiate the thesis that interface instabilities are the cause of the quenches.