Just installed a brand new InSinkErator Evolution Spacesaver garbage disposal unit ($180 at Lowes) and double-checked the cord (used the old one) and noticed that when my wife threw the switch (I was watching from underneath), I saw sparks within the bottom of the housing. I checked my mom's garbage disposal and did not see any sparks. I called up InSinkErator and the woman on the phone said "that's normal". Uhm, I should have asked if she was an electrician. I double checked the the white wire went to the neutral prong/wide prong/left (of a 3-prong cord) and the black wire went to the right/narrow prong, even though several youtube instructional video's said "it didn't matter"?

Any suggestions?

As far as I know you should not see sparks.

Recheck your line cord hook up in the unit.

Did your cut back the line cord some so that you connected to nice clean copper. If not you should.

If you Google "InSinkErator Evolution Spacesaver" there are lots of videos on the install. I did not see sparks in any of them that showed the unit running.

If you talk to that woman again tell her you want that sparks are normal in writing. So that if your house burns down you will have proof that they are responsible.