trip
n.— «In the parlance of the electric power industry, a “trip” means a piece of machinery stops operating. A series of feedwater system pumps supplying water to TMI-2’s steam generators tripped on the morning of March 28, 1979. The nuclear plant was operating at 97 percent power at the time. The first pump trip occurred at 36 seconds after 4:00 a.m.» —“Three Mile Island Nuclear Accident: March 28, 1979″ Three Mile Island Alert , 1979. (source: Double-Tongued Dictionary)