AMSCO

Description of Event or Problem

THE USER FACILITY REPORTED THAT THE STEAM GENERATOR OF THEIR AMSCO 600 STERILIZER OVERHEATED AND OBSERVED A SMALL FLAME. THE DAMAGE WAS CONTAINED TO A SMALL AREA. NO REPORT OF INJURY.

Additional Manufacturer Narrative

A STERIS SERVICE TECHNICIAN ARRIVED ONSITE FOLLOWING THE REPORTED EVENT TO INSPECT THE UNIT AND FOUND THAT THE GENERATOR'S CONTACTOR SHORTED DUE TO LOOSE WIRING. TO RESOLVE THE ISSUE, THE TECHNICIAN WILL REPLACE THE GENERATOR CONTROL BOX. A FOLLOW-UP MDR WILL BE SUBMITTED ONCE REPAIRS ARE COMPLETED.

Additional Manufacturer Narrative

IN THE INITIAL REPORT, B2 "DEATH" WAS INADVERTENTLY SELECTED IN ERROR BY THE REPORT SUBMITTER. THERE WAS NO REPORT OF DEATH OR INJURY ASSOCIATED WITH THE SUBJECT EVENT.

Additional Manufacturer Narrative

THE COMPONENTS SUBJECT OF THE EVENT WERE RETURNED TO STERIS ENGINEERING FOR EVALUATION. THE INITIAL EVALUATION FOUND EVIDENCE OF CHARRING ON THE HEATER CONTACTOR OF THE INTEGRAL STEAM GENERATOR AND SOME OF THE SURROUNDING COMPONENTS. THE HEATER CONTACTOR WAS UNABLE TO BE FURTHER TESTED DUE TO THE DAMAGE; HOWEVER, THE CHARRING IS INDICATIVE OF AN ELECTRICAL SHORT WHICH LIKELY RESULTED IN THE REPORTED EVENT. CONTRARY TO THE INITIAL REPORT, THE WIRING TO THE HEATER CONTACTOR WAS NOT FOUND TO BE LOOSE DURING THE EVALUATION. TO FURTHER INVESTIGATE THE CAUSE OF THE POTENTIAL ELECTRICAL SHORT, AN IN-DEPTH EVALUATION OF THE RETURNED COMPONENTS WAS PERFORMED BY ENGINEERING. THIS EVALUATION DETERMINED THAT THE OPERATING PRESSURE SWITCH WAS NOT FUNCTIONING AS EXPECTED. THE PRESSURE SWITCH MONITORS THE STEAM PRESSURE, AND CONTROLS THE ACTIVATION AND DEACTIVATION OF THE HEATER TO START OR STOP GENERATING STEAM. THE TESTING PERFORMED BY ENGINEERING FOUND THAT THERE WAS A DELAY IN THE OPENING AND CLOSING OF THE PRESSURE SWITCH RESULTING IN AN INTERMITTENT CONNECTION WITH THE HEATER CONTACTOR. THIS INTERMITTENT CONNECTION CAUSED PARTIAL, REPEATED ACTIVATIONS AND DEACTIVATIONS OF THE HEATER CONTACTOR. OVER TIME, THESE PARTIAL ACTIVATIONS MAY RESULT IN ARCING, OXIDATION, AND HEAT TO BUILD ON THE INTERNAL CONTACTS OF THE HEATER CONTACTOR. AN EXACT CAUSE OF THE ISSUE WITH THE PRESSURE SWITCH COULD NOT BE DETERMINED. ADDITIONALLY, THE STERILIZER'S CYCLE TAPES WERE REVIEWED AND FOUND THAT PRIOR TO THE REPORTED EVENT THE STERILIZER ALARMED "TOO LONG TO SEAL OE DR" AND ABORTED THE CYCLE. THIS ALARM MAY OCCUR WHEN THERE IS NOT ENOUGH STEAM SUPPLY TO SEAL THE DOOR. THE DECREASED STEAM SUPPLY IS ATTRIBUTED TO THE LIKELY ELECTRICAL SHORT OF THE STEAM GENERATOR'S HEATER CONTACTOR. THE AMSCO 600 STEAM STERILIZER OPERATOR MANUAL STATES THE FOLLOWING TO ADDRESS THIS ALARM (126): "1. IF ELECTRIC STEAM GENERATOR IS USED, CONTACT FACILITY BIOMED TO ENSURE 3 PHASE VOLTAGE IS AVAILABLE. 2. CONTACT STERIS IF ALARM RECURS." BASED ON OUR INVESTIGATION RESULTS, AN EXACT CAUSE OF THE LIKELY ELECTRICAL SHORT COULD NOT BE DETERMINED. HOWEVER, THE ISSUES IDENTIFIED DURING OUR EVALUATION VERY LIKELY CONTRIBUTED TO THE REPORTED EVENT. A FULL COMPLAINT REVIEW DETERMINED THIS TO BE AN ISOLATED EVENT. THE ASMCO 600 STEAM STERILIZER IS DESIGNED WITH FLAME-RESISTANT MATERIALS AND IS CERTIFIED BY INTERTEK TO UL 61010-1:2012 3RD ED./CSA C22.2#61010-1-12:2012, 3RD ED. SAFETY REQUIREMENTS FOR ELECTRICAL EQUIPMENT FOR MEASUREMENT, CONTROL AND LABORATORY USE, PART 1, AND UL 61010-2-040:2021, 3RD ED/CSA C22.2#61010-2-040:2021 3RD ED., SAFETY REQUIREMENTS, PART 2-040 - PARTICULAR REQUIREMENTS FOR STERILIZERS AND WASHER-DISINFECTORS TO TREAT MEDICAL MATERIALS. TO ADDRESS THE ISSUE, THE TECHNICIAN REPLACED THE NECESSARY COMPONENTS, TESTED THE STERILIZER, AND CONFIRMED IT TO BE OPERATING ACCORDING TO SPECIFICATION. NO ADDITIONAL ISSUES HAVE BEEN REPORTED.