The washing machine at Edward Nauman's house kept overflowing
and flooding the floor, so he designed a flood sensor to cut the power to the
washing machine if the water in the drain rose within 1.5 inches from the top.
The level sensor is mounted in a hole drilled in the drain pipe and the
electronics are mounted in a box on the wall next to the power outlet. The box
plugs into the wall and the washer plugs into the box. When the water rises to
the sensor, a switch in the box cuts the power.
Shutting off the machine at the first sign of overflow is one way to stop the symptom, but clearing the drrain would be an actual fix. See "the case of the refilling washing machine." The big problem in this tale is poor drain function, which will only get worse.
Industrial workplaces are governed by OSHA rules, but this isn’t to say that rules are always followed. While injuries happen on production floors for a variety of reasons, of the top 10 OSHA rules that are most often ignored in industrial settings, two directly involve machine design: lockout/tagout procedures (LO/TO) and machine guarding.
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