scram switch [from the nuclear power industry] n. An emergency-power-off switch (see Big Red Switch), esp. one
positioned to be easily hit by evacuating personnel. In general,
this is *not* something you frob lightly; these often
initiate expensive events (such as Halon dumps) and are installed
in a dinosaur pen for use in case of electrical fire or in
case some luckless field servoid should put 120 volts across
himself while Easter egging. (See also molly-guard,
TMRC.)