Summary:
My garbage disposal is spinning counterclockwise (reverse, I think) after rewiring the gang box for a dishwasher. The appliances share a neutral. Am I imagining this?

Detail:
Last night I installed a new dishwasher, and ran new cable from the gang box because the old cable had no ground wire. The gang box also serves the garbage disposal (Badger 5).

The house (Loudoun County, Virginia) was built in 1955, and the supply cable to the gang box has two black wires (live) and one red wire (neutral).

I mounted a metal outlet box nearby and ran wires from the gang box, grounding on the original gang box. I tested the outlets with a plug-style analog voltage detector. The detector showed proper wiring with ground.

I never disconnected the black (hot) wire from the garbage disposal, and I tied the disposal's white wire to the red (neutral) along with the neutral from the dishwasher.

The dishwasher is plugged into the outlet and runs fine. The detector says the wiring to the outlet is fine. But I'm convinced that the disposal should be running clockwise, and that it sounds different (quieter) than it did before.

Many thanks in advance for your thoughts.

 

A single phase motor can not be reversed by swapping black and white. Does the garbage disposer chop garbage the way it should? If it does I wouldn't worry about it.

See Aandpdan's post below on reversible garbage disposers.

 

Actually, there are garbage disposers that do "auto-reverse." It helps clear a jam as all you have to do is turn it off and back on.

What model disposer is it?

 

The disposal is a Badger 5.

 

The Badger 5 is from Insinkerator and is not of the reversing type of units.

http://www.insinkerator.com/en-us/Do...ifications.pdf

 

Your disposer is still doing what it did before you re-did the wiring for the dishwasher receptacle. A 120V AC motor cannot be reversed by reversing the wires feeding it.

I'm curious about a couple of things you mentioned though. One is that you said Sounds like an improvement, but is the J-box grounded?

The other is that you said thatThat's very unusual. A neutral wire should be either white or gray, and standard cable doesn't have two wires of the same color in it. Is this actually three individual conductors pulled in conduit? Are those three wires all of the wires feeding in?

 

Thank you, everyone, for your great responses. I love this forum.

Fortunately, yes. I converted several two-prong outlets to three-prong last fall, and found that the original wiring used all-metal conduit and each box was grounded. Still, one of the reasons that I set up an outlet was to test for ground using the receptacle tester.

Yes, the j-box has three conduits attached. One connected to the garbage disposal, one to the dishwasher. The other is the supply, and has two black wires and one red. I can't explain it except that the house was built in 1955 and was a custom build, possibly by the homeowner himself.

Thanks again!

 

Got it, thanks. That is very strange wire selection. I hope it wasn't done by an electrician.