On Mon, 21 Jan 2013 21:22:25 -0600, wrote:

Why do Microwave ovens that have a rotating platter, change direction?
The platter seems to usually spin counter-clockwise. However, if I turn
it off to stir or check the food, the platter begins to turn clockwise.
It dont change direction once it's running, only when I stop it and
restart. This is the second microwave I've had that does this, and they
were different brand names.

Not only do I wonder *why* they change rotation, but *how*? I'm
guessing they use a shaded-pole motor (I'm not sure), and as far as I
know, those motors only turn one direction. Either CW or CCW.
Unless there's a belt driving them, there is not much room for any other
type of motor in the base of the oven.

Anyone know anything about this?

I see some suggest it's just random but I think it's random "on
purpose". In the old days they always went the same direction. What
I read was that they purposely make, or at least allow, them to revere
direction because they found that was a good way to dislodge crumbs
that would otherwise get stuck on/under the little support wheels and
make the turntable jerk/squeak/squeal.