Electrical Wiring in the Home/Lights not working

Advertisement


Question
Hi J. Thanks for volunteering. My house was constructed in 2007. We are original owners. Two days ago we noticed that we have two light switches that don't work on the first floor of our house. One leads up the steps and controls 3 lights. The other is near the door that leads to the garage. This one only controls one light. I checked all GFCI outlets that I could find on the first floor and they seem OK. I flipped all the fuses off and on one by one by the lights still don't work. I also flipped the main power off and on. I pulled both wall plates off and I don't see any loose connections.  The wires are all inserted into the back, not wrapped around the screws. Do you know what the problem could be? I should tell you that a couple of days before this I had to fix a loose connection in an outlet in the kitchen that was causing 3 other outlets next to it not to work but they are still working fine.

Regards,
Paul

Answer
These devices are called "stab back" for obvious reasons. The following excerpt is directly from a 2005 UL manual:

         
wired clamping types are suitable for use with both solid and stranded
building wires.
Screwless terminal connectors of the conductor push-in type (also
known as ‘‘push-in-terminals’’) are restricted to 15 A branch circuits and
are for connection with 14 AWG solid copper wire only. They are not
intended for use with aluminum or copper-clad aluminum wire, 14 AWG
stranded copper wire, or 12 AWG solid or stranded copper wire.

As you see use of the stab back, back stab, or push in terminals whichever you wish to call them are restricted to a 15 amp circuit and ONLY with copper conductors. The aluminum solid conductor was found to loosen on these type of connections. It has also been a problem even if using a copper conductor. I installed all of the wiring and devices in my home and never considered using the stab back connection point, I used the screw terminals on every device due to the fact I have seen so many failures using this type of connection point. I my opinion
I would check every device and change the connections to the screw terminals. Somewhere along th is circuit it would only take one device will a slightly loose connection to be creating your problem. The bigger problem is this loose connection is very capable of overheating and creating a fire hazard. Not in any way trying to put a scare on anyone, but I have seen and read of too many failures and in some cases they did indeed cause a fire. Look up problems with stab back devices, there are many testimonials out there. It may be a difficult task if every device was connected this way, but you will have to weigh the alternative. Sorry your home was built when this was a common practice, but again in my opinion no elecrician who is very concerned about his reputation would have used this connection method. Thanks for asking, J and let me know what you decide to do.  
About Electrical Wiring in the Home
This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

All Answers


Answers by Expert:


Ask Experts

Volunteer


J Cook

Expertise

General electrical wiring, including but not limited to, residential, panelboards, control wiring, low voltage wiring, Heating and A/C control wiring, single and three phase wiring.

Experience

I have been doing electrical since high school. I have been licensed by the State of North Carolina for ten years and am currently the Building Maintenance Superintendent for a municipality. I have extensive control wiring experience.

Organizations
Refrigeration Service Engineers Society.

©2016 About.com. All rights reserved.