"J. Clarke" wrote in
:


While I was confirming that Grainger has capacitor-start split-phase
motors in stock,

LOL.

While "more efficiency" is a good thing, I find myself wondering how
much the average efficiency of small motors will actually be increased
by this, and what the side effects will be.

I beleive the expectation is to go from ~75% efficient (mechanical
power out / electrical power in) to ~80%.

Generally speaking
"increased efficiency" translates to "costs more up front" so I
suspect we can expect the prices of tools using "general purpose
motors" to go up.

That is likely to be the case, since a big part of improving
efficiency is reducing resistive losses, and the way to do
that is thicker copper wiring.

Another issue is that the higher efficiency motors are likely
to be larger than the current ones, so manufacturers may have
to redesign their mountings. (which may also be a problem for
anyone replacing a bad motor in an older tool).

Then there's a little detail--"Run capacitor provides winding with
increased energy to help improve efficiency". I don't know if that's
specific to Dayton or if it's across the board--if so, if all new
general purpose motors are required to be capacitor-run, then we can
expect to have to replace those capacitors with some regularity.

Probably across the board. A run capacitor improves the motor's
power factor, which reduces resistive losses. So it's a big
help in improving efficiency.

Note that improving efficiency means less electrical energy is
lost as heat, so capacitor lifetime may improve.

BTW, before a political debate starts on this, it should be
noted that the legislation requiring the high efficiency
motors dates to the GW Bush administration.

John