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NASA-LLIS-0563
Lessons Learned – Electrical Connectors
Year: 1997
Abstract: Description of Driving Event:
A routine hookup and pump testing was being attempted on LOX barge #5 by Test Complex technicians. They were working under a process plan and standard operating procedure as required. The testing was necessary to functionally check the system after repair was performed.
The technicians encountered difficulty in making a threaded electrical connection between the 480 VAC shore power cable connector and the LOX barge receptacle. The cable was insufficient in length to make a comfortable hookup. They pulled on it attempting to gain range by decreasing the slack in the line. Although they were successful in mating the connectors, the weight and angle of the cable applied undue stresses. The lead technician was under the impression the connection was adequate due to the fact the associated retaining nut felt to tighten by hand. A strap wrench was therefore used to further tighten the nut.
When power was applied to energize the system, a high current arc was produced within the connection. The forces exerted by this arc resulted in the connector plug being forcefully ejected free from the receptacle. This action caused the connector plug to come in contact with the barge access ramp. The chain holding the associated aluminum connector plug moisture/dust cap was severed. The cap was then propelled and struck a technician working nearby behind the ear.
A routine hookup and pump testing was being attempted on LOX barge #5 by Test Complex technicians. They were working under a process plan and standard operating procedure as required. The testing was necessary to functionally check the system after repair was performed.
The technicians encountered difficulty in making a threaded electrical connection between the 480 VAC shore power cable connector and the LOX barge receptacle. The cable was insufficient in length to make a comfortable hookup. They pulled on it attempting to gain range by decreasing the slack in the line. Although they were successful in mating the connectors, the weight and angle of the cable applied undue stresses. The lead technician was under the impression the connection was adequate due to the fact the associated retaining nut felt to tighten by hand. A strap wrench was therefore used to further tighten the nut.
When power was applied to energize the system, a high current arc was produced within the connection. The forces exerted by this arc resulted in the connector plug being forcefully ejected free from the receptacle. This action caused the connector plug to come in contact with the barge access ramp. The chain holding the associated aluminum connector plug moisture/dust cap was severed. The cap was then propelled and struck a technician working nearby behind the ear.
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T15:57:43Z | |
| date available | 2017-09-04T15:57:43Z | |
| date copyright | 09/08/1997 | |
| date issued | 1997 | |
| identifier other | RBCEQCAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/60997 | |
| description abstract | Description of Driving Event: A routine hookup and pump testing was being attempted on LOX barge #5 by Test Complex technicians. They were working under a process plan and standard operating procedure as required. The testing was necessary to functionally check the system after repair was performed. The technicians encountered difficulty in making a threaded electrical connection between the 480 VAC shore power cable connector and the LOX barge receptacle. The cable was insufficient in length to make a comfortable hookup. They pulled on it attempting to gain range by decreasing the slack in the line. Although they were successful in mating the connectors, the weight and angle of the cable applied undue stresses. The lead technician was under the impression the connection was adequate due to the fact the associated retaining nut felt to tighten by hand. A strap wrench was therefore used to further tighten the nut. When power was applied to energize the system, a high current arc was produced within the connection. The forces exerted by this arc resulted in the connector plug being forcefully ejected free from the receptacle. This action caused the connector plug to come in contact with the barge access ramp. The chain holding the associated aluminum connector plug moisture/dust cap was severed. The cap was then propelled and struck a technician working nearby behind the ear. | |
| language | English | |
| title | NASA-LLIS-0563 | num |
| title | Lessons Learned – Electrical Connectors | en |
| type | standard | |
| page | 2 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1997 | |
| contenttype | fulltext |