Changing to GFI outlet and adding outlet

Reply

  #1  
Old 02-17-06, 01:08 PM
Member
Thread Starter
Join Date: Jan 2003
Location: USA
Posts: 34
Changing to GFI outlet and adding outlet

In my kitchen, I want to add a receptacle to plug my microwave in. The outlet that I want to pull from seems to be the only one on this specific breaker. However, when I pulled the outlet from the wall, expecting to see 2 wires coming into the box, I was surprised by what I saw. I'll try to describe it. Keep in mind, this house was built in the 50's, so there is no ground wire. I would also appreciate thoughts on that. I'll do my best to describe what I saw.

In the box there are two groups of wires. One of the groups has 3 wires in it, 1 white, 1 black, and 1 red(no bare). The other group has two wires, 1 black and 1 white (no bare). The group with three is coming from the breaker box, where the black and red wires are on two separate breakers. The group (I don't know the appropriate word for this) with 2 wires goes off to another outlet.

In the outlet box, the two black wires are tied together. Both white wires are attached to the left side of the outlet. The red wire is the only thing connected to the right side of the outlet.

I understand (I think) philosophically what is happening. Rather than running two wires from the Breaker box to approximately the same place, bring the 110 on two separate wires. However, can the neutral carry 220 back to the breaker?

So, the real question: My goal was to replace this outlet with a GFI outlet last night and also branch off of the GFI outlet to a new outlet. But the GFI outlet kept tripping. (I was doing something wrong).

Ideas?

Thanks for any thoughts!
 
Sponsored Links
  #2  
Old 02-17-06, 01:14 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
This is a multi wire circuit. The neutral wire is grounded, so it has a voltage of zero, or close to it. It does carry current, but it only carries the difference in current between what is on the two hot wires.

Leave this circuit alone. It has no ground, so you can't extend it. You also don't want an ungrounded circuit for a microwave.

Run a new circuit for your microwave.
 
  #3  
Old 02-17-06, 01:18 PM
Member
Thread Starter
Join Date: Jan 2003
Location: USA
Posts: 34
The microwave is currently running on an ungrounded outlet, as is the rest of the kitchen....

thoughts? do all of the outlets need to be fixed?

THANK YOU!
 
  #4  
Old 02-17-06, 01:50 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
You should, sooner rather than later, rewire the kitchen to provide a ground to ALL the receptacles.

How is it that you have three prong receptacles with no ground? If you have been using the microwave with no ground and no GFCI protection then you have been using it in an unsafe manner. If you have other three prong receptacles in the kitchen that are not grounded, then they are also unsafe.


Since you cannot (by code) extend an ungrounded circuit, you have no choice here.

So run a new circuit for your microwave.
 
  #5  
Old 02-17-06, 01:57 PM
Member
Thread Starter
Join Date: Jan 2003
Location: USA
Posts: 34
The other outlets have GFCI's on them, or before them on the circuit. Should they be upgraded also? Does having GFCI outlets cover the issue of no ground present?

When I was pulling the outlets out of the old metal boxes, they had green wires connected to the box, but that was it. They were three prong receptacles. I didn't extend any of those, just replaced the old 3prong receptacles with GFCI's. In order for the GFCI outlets to fit in the box, I replaced the old metal boxes with the "new work" plastic blue boxes from Home Depot.

Thank you for your help!
 
  #6  
Old 02-17-06, 02:23 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
A green wire to a metal box means nothing if the boxes are not grounded. I assume this is old style NM cable that has no ground wire?

A GFCI does not provide a ground. A GFCI does provide a safe means of plugging in a three prong device that uses the ground for safety. However, if the ground is used to dissipate a power surge or as a reference point for electronic circuits, the GFCI does provide the ground that is needed.

You did a smart thing by installing GFCI receptacles. Yes, those circuits should be upgraded to be grounded.

If you remodeled you kitchen enough to replace electrical boxes, then you were required to bring it up to code, which you apparently did not do. Obviously you had no inspection done, which was a mistake on your part.
 
  #7  
Old 02-17-06, 02:44 PM
Member
Thread Starter
Join Date: Jan 2003
Location: USA
Posts: 34
Yes, it is the old NM cable
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'