In trader_4 writes:

[snip...]

As some background, that was allowed so that items such as dryers
(or more commonly, ovens) whose main power draw (such as the
heating elements) was 240V, could also operate some secondary
items (such as the timer, lighting, fans..) at 120V.

This was Way Back, before routine international shipping, when
getting 240V versions of clocks and light bulbs was a pain...

Funny then that today they typically still require 120V. It's also illogical
to suggest that the major companies building millions of machines
can't easily source
240V timers or light bulbs. Many of them were also major electrical
component suppliers themselves too. Westinghouse can't find or make
a 240V timer or bulb? It is an interesting question as to why they evolved
to require 120V, but I doubt that it's because 240V timers were hard to source.

Legacy and inertia.

Same reason, more or less, that many of the hybrid cars, with their
high voltage DC battery systems, still (usually) have a second 12V
wiring harness for the radio (well, "enterntainment system"),
lighting, and, to quote from the first season of Gilligan's Island,
"and all the rest".


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