scope:

Abstract:

On Monday, September 24, 2007, at approximately 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. Since 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 Assembly (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 gloves (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