GFCI and knob/tube


Old 01-02-06, 11:05 AM
Visiting Guest
Posts: n/a
GFCI and knob/tube

I have knob and tube wiring in my kitchen. Is there a way I can put a GFCI outlet in as a replacement for the current non-GFCI outlet? Can I ground it to the metal box? Help!
Sponsored Links
Old 01-02-06, 12:03 PM
Join Date: Nov 2004
Location: USA
Posts: 973
Yes, you can do this. Just connect the hot wire to the gold LINE screw, and the neutral wire to the silver LINE screw. Unless the metal box is grounded, do not connect anything to the green grounding screw.

If you have knob and tube wiring, the metal box is probably not grounded. You can test to see by touching a one probe of a neon electrical tester to the box, and the other probe to the hot wire to see if it lights.

The nice thing about a GFCI receptical is that it provides a legal way of replacing an ungrounded receptical with a three prong receptical. Even though the GFCI is ungrounded in this case, it provides similar protection as to what a ground wire would have provided (as well as providing protection against certain bad electrical events that a ground wire does not protect against).

The GFCI receptical should come with stickers that say "No equipment ground". Unless you find that the box is indeed grounded, put one of those stickers by the GFCI receptical so those in the future will know it is ungrounded.

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