CONSUMERS ENERGY CO

Incident Narrative

ON MARCH 15, 2022 AT APPROXIMATELY 16:20 HOURS CONSUMERS ENERGY GAS CONTROL RECEIVED A FIREGATE TROUBLE ALARM AT THE WHITE PIGEON COMPRESSOR STATION. WHITE PIGEON COMPRESSOR STATION IS LOCATED AT 68536 A ROAD, WHITE PIGEON TOWNSHIP, (ST. JOSEPH COUNTY) MICHIGAN. A STATION MECHANIC WAS DISPATCHED AND ARRIVED AT THE SITE AT APPROXIMATELY16:37 HOURS. THE MECHANIC OBSERVED MULTIPLE ESD VALVE POSITION FAULTS AT THE STATION CONTROL SCREEN AND GAS WAS BEING RELEASED NEAR PLANT 3, LATER DETERMINED TO BE A RELEASE AT THE PLANT 3 SUCTION BLOWDOWN VALVE (VALVE 635). THE MECHANIC ACTIVATED THE FIREGATE SYSTEM AT APPROXIMATELY 16:39 HOURS TO ISOLATE AND RELIEVE ALL GAS FROM THE PLANT 3 PIPING. THE VENTING WAS COMPLETE AT APPROXIMATELY 16:43 HOURS AND A SITE INSPECTION WAS COMPLETED TO CONFIRM ALL POTENTIAL HAZARDS WERE ELIMINATED. ON MARCH 16, 2022 AN INITIAL SITE ASSESSMENT AND INCIDENT REVIEW WAS CONDUCTED WITH THE MICHIGAN PUBLIC SERVICE COMMISSION. THE CAUSE INVESTIGATION CONTINUED FOR SEVERAL WEEKS AND INCLUDED ELECTRICAL TESTING AND FUNCTIONAL TESTING OF THE VALVE. BASED ON THE EVALUATION, REPAIR AND REPLACEMENT OF SELECTED COMPONENTS WERE COMPLETED AND SENT TO THE VENDOR FOR FURTHER EVALUATION. ADDITIONAL ACTIONS WERE COMPLETED ON SIMILAR EQUIPMENT PRIOR TO RETURNING PLANT 3 TO SERVICE ON APRIL 1, 2022 AT APPROXIMATELY11:50 HOURS. AT THE TIME OF THIS REPORT, THE PROBABLE CAUSE HAS BEEN DETERMINED TO BE AN ELECTRIC FAULT THAT OCCURRED IN THE VALVE ACTUATOR TERMINAL BOX DUE TO MOISTURE THAT EITHER ENERGIZED THE OPEN SOLENOID OR DE-ENERGIZED THE ESD SOLENOID CAUSING THE VALVE TO OPERATE AND GAS TO BE RELEASED. THE ESD SOLENOID AND THE RELAY MODULE HAVE BEEN SENT TO ROTORK AND DET-TRONICS RESPECTIVELY FOR ADDITIONAL VENDOR EVALUATION TO DETERMINE IF EITHER COMPONENT MAY HAVE CAUSED OR CONTRIBUTED TO THE EVENT. THE LABORATORY REPORTS FROM THE VENDOR, PETER PAUL ELECTRONICS CONCLUDED THE FAILURE TO BE OPEN CIRCUITS WITHIN THE COIL. THIS OCCURS WHEN THERE IS A BREAK IN THE WIRES OR CONNECTION. THE LAB ANALYSIS SHOWS THE LEAD CONNECTORS WERE INTACT, CONFIRMING THE BREAK WAS INSIDE THE COIL. THIS WAS CONFIRMED WHEN THE LAB REPLACED THE COIL IN THE VALVE AND THE OPEN CIRCUIT ISSUE WAS NOT OBSERVED. CONFIRMING THE ROOT CAUSE TO BE THE ESD SOLENOID FAILING AND OPERATING THE VALVE.