1、Lessons Learned Entry: 2696Lesson Info:a71 Lesson Number: 2696a71 Submitting Organization: SSCa71 Submitted by: Eric Trailla71 POC Name: Mary Byrda71 POC Email: mary.r.byrdnasa.gova71 POC Phone: 228.688.2635Subject: Substation Arc Flash Mishap Abstract: On Monday, September 24, 2007, at approximatel
2、y 12:50 pm Central Daylight Time (CDT), a worker suffered second degree burns to the hands as a result of exposure to an electrical arc flash. The arc flash was caused by an electrical short while servicing a kilowatt-hour meter; located at Stennis Space Centers Test Complex Area Building 4400. Sinc
3、e Worker 1 was hospitalized for inpatient care within 30 days of the incident, the incident was classified as a Type B Mishap in accordance with NPR 8621.1B, reference NASA IRIS incident number 2007-267-00006. The proximate (direct) causes leading to the mishap are listed below: 1. Meter Panel Assem
4、bly (MPA) being serviced by the worker was in an electrically energized state 2. Worker 1 opened MPA knife switches in preparation to review the kilowatt meter 3. Energized knife switch blades extended beyond plane of MPA cover opening 4. Worker 1 was not wearing leather protected, voltage rated glo
5、ves (PPE) 5. Worker 1 was not being monitored by another worker (i.e. buddy system) 6. Worker 1 placed metal MPA cover back onto the MPA enclosure 7. Metal MPA cover contacted the electrically energized knife switch blades causing electrical arc flash at MPA Description of Driving Event: At the time
6、 of the mishap, the injured worker and a co-worker were removing 277/480 volt electrical kilowatt-hour meters for calibration. The meters are associated with the building power distribution system serving Building 4400. Unfortunately, while performing the meter removal task, the affected Provided by
7、 IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-employee installed the metal cover of a meter panel enclosure onto electrically energized knife switches located within the enclosure. This action caused an electrical short resulting in the arc flash that injured
8、 the worker and also caused damage to the meter panel assembly. The worker was not wearing the PPE gloves required to perform the task, (i.e., the worker installed the cover with bare hands.)Lesson(s) Learned: 1. Failure to implement a Safety First type of philosophy amongst employees may lead to sa
9、fety incidents. 2. Without proper contract surveillance, incompliance with critical contractual and safety regulations (Occupational Safety and Health Act, OSHA) may not be identified and lead to safety incidents. 3. Failure to thoroughly assess the hazards of a job/task prior to performing the task
10、 may lead to safety incidents. 4. Failure to clearly identify alternative means of performing work on energized systems results in hazardous work that is avoidable. 5. Failure to verify proper training and apply thorough supervision may lead to safety incidents. 6. Failure of all parties to clearly
11、communicate the impacts of an outage will result in the misconception that the outage cannot be scheduled and planned appropriately and result in pressures to perform work on energized systems that is avoidable. Recommendation(s): 1. Management should improve their approach for assuring that employe
12、es consider the safer means of performing a task before they begin. The approach should be clearly communicated to all through a formal work permit process for assessing the risk of working on electrically energized systems as defined in NFPA 70E,paragraph 110.8(B). 2. The contractor should establis
13、h a formal and auditable permitting process for energized electrical work per the guidelines of NFPA 70E and OSHA requirements 3. NASA should prepare and execute a surveillance plan for providing oversight of contracts that address compliance with contractual safety requirements (e.g., National Fire
14、 Protection Association (NFPA) 70E, Standard for Electrical Safety in the Workplace) and federal law regarding safety (i.e., OSHA Regulations). 4. A hazard analysis should be performed for all critical work that includes an overall risk assessment, PPE evaluation, safe operating procedures and appro
15、priate training. 5. Supervisors/managers should ensure that employees are knowledgeable of the systems they work with and tasks that they perform, providing training where necessary. 6. When it appears that tasks cannot be performed in a safe de-energized state, the task should be presented in an op
16、en forum with management and knowledgeable personnel for further assessment. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: National Fire Protection Association (NFPA) 70E
17、, Standard for Electrical Safety in the WorkplaceMission Directorate(s): a71 Space OperationsAdditional Key Phrase(s): a71 Safety and Mission Assurance.a71 Additional Categories.Personal Protective Equipmenta71 Safety and Mission Assurance.Maintenancea71 Additional Categories.a71 Additional Categori
18、es.FacilitiesMishap Report References: NASA IRIS incident number 2007-267-00006Additional Info: a71 Project: N/AApproval Info: a71 Approval Date: 2010-06-11a71 Approval Name: mbella71 Approval Organization: HQProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
