Wiring outlet for dishwasher and disposer


  #1  
Old 07-06-11, 10:28 PM
M
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Wiring outlet for dishwasher and disposer

I had to remove the outlet that fed the dishwasher and disposer. I made notes on how the existing wiring was. But I don't understand why things were wired this way. Maybe I got my notes wrong and need some help understanding...

Since the outlet feeds the dishwasher and disposer, I presume one is always on and the other is controlled by a switch.

There is one 3 wire cable coming into the outlet (red, black, white and ground) and another 2 wire cable coming in as well (black, white and ground).

From the 3 wire cable, I would have connected the black and white to the top outlet and left the red unused. From the 2 wire cable, I would have connected the black and white to the lower outlet. (1) Would this be the right way to do it?

Instead, I made notes saying that the red from the 3 wire was connected to the hot of the top outlet, the black from the 3 wire connected to the white of the 2 wire. The black from the 2 wire connected to the hot of the bottom outlet. And white from the 3 wire connected to the neutral(s). (2) Can anyone please help me understand what was being done here?

TIA.
 
  #2  
Old 07-06-11, 11:26 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
You have a wall switch near the sink to control the garbage grinder, correct? That will be the two-wire cable. This arrangement is called a switch loop.

If you are using a new receptacle rather than the original you will first need to break out the tab between the brass-colored screws. This isolates the two individual receptacle locations for use with a "Multi-
Wire Branch Circuit" (MWBC) which is the three-wire cable.

Follow your note as it IS the correct wiring for these two circuits.

Wrap a bit of black tape (or use a black marking pen) on the white wire of the two-wire cable to denote it IS a "hot" lead in a switch loop. Although not absolutely necessary you should also do this "re-identification" at the switch itself.
 
  #3  
Old 07-07-11, 10:07 PM
M
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thaks Furd. You are right. The two-wire was not live, but connected to the switch. I was assuming both the three-wire and two-wire to be live and the switch being in serial to one of them, that was the source of my confusion. I now have one outlet always on (red wire from three-wire) and another controlled by the switch (three-wire black goes to switch and back). Thanks again.
 
  #4  
Old 07-07-11, 11:07 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
You're welcome! I just wish that all the problems posed on this site were so easy.
 
  #5  
Old 07-08-11, 07:16 AM
Justin Smith's Avatar
Member
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,272
Upvotes: 0
Received 1 Upvote on 1 Post
I just wish that all the problems posed on this site were so easy.
But then there would be no fun in it
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: