Light flickering, what is the cause???


  #1  
Old 08-01-15, 03:54 PM
K
Member
Thread Starter
Join Date: Jul 2015
Location: USA
Posts: 19
Upvotes: 0
Received 0 Upvotes on 0 Posts
Light flickering, what is the cause???

I was able to connect a ceiling light fixture to a sconce light to one light switch. I tested it out and it works perfect. I then remove the light switch and added a GFCI and connected the GFCI to the light switch. I was able to turn on both the sconce and ceiling light, but when I turn it off the ceiling light turns off but the sconce start flickering. I'm using CFl light bulbs for both the sconce and ceiling light fixture. What is causing the sconce to flicker when connected to the GFCI directly but not when connected to the light switch. I tried connecting the hot and neutral to the light switch and then GFCI but I still get the sconce to flicker.
 
  #2  
Old 08-01-15, 06:08 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
I tried connecting the hot and neutral to the light switch
A neutral is never connected to a regular switch. Are you confusing a white wire with a neutral? Do you only have two wires at the switch?

What kind of GFCI device? Do you mean a GFCI switch or GFCI receptacle or what?
 
  #3  
Old 08-02-15, 05:36 AM
K
Member
Thread Starter
Join Date: Jul 2015
Location: USA
Posts: 19
Upvotes: 0
Received 0 Upvotes on 0 Posts
I meant the white wire and GFCI receptable. I connected the light switch first to the black and white wires and both lights were working properly. I then added the GFCI recep. Both lights turn on but when off the sconce starts flickering but ceiling light is off.
 
  #4  
Old 08-02-15, 06:41 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,556
Upvotes: 0
Received 285 Upvotes on 260 Posts
You may not connect a GFCI receptacle hot and neutral terminals (black lead and white lead; gold screw and silver screw) to the same two wires that were connected to a switch whether or not the switch is still connected, all other things equal.

With only two wires coming into the switch box (and originally connected to a switch) neither is (neither should be) neutral. The most up to date code requires that, if one of these wires is white, that it be marked with a band of colored (not green) tape or stain at both ends. One is the power source. The other (this one may not be the white one) sends switched power to the lights or whtever.

If you connect a GFCI receptacle incorrectly as described above its presence alone might cause one or more low wattage lights such as CFLs or LCDs in the circuit to flicker. This is because the GFCI unit consumes a small amount of power to do its ground fault monitoring function. This power draw is pulled through the light controlled by the switch that you also had connected to the black and white wires. This GFCI receptacle will not supply power correctly to thing you plug in but may then result in erratic operation of the aforementioned lights.

Your situation is one reason why the most up to date code nowadays requires a third wire in the cable if just one cable comes to the switch box. (Older homes' wiring may be grandfathered.) The red and black wires would be the ones to be connected to the switch. The white wire, if not used right away, would be available as the neutral to connect to receptacles, some kinds of dimmers or motion control switches, etc. or extend power from the switch box to other locations.
 

Last edited by AllanJ; 08-02-15 at 07:05 AM.
  #5  
Old 08-02-15, 09:15 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
To sum up Allan,s very good reply. You do NOT have power at the switch. Therefor you can not connect a receptacle at the switch. Power is a hot and a neutral. You do not have a neutral.
 
  #6  
Old 08-02-15, 03:58 PM
K
Member
Thread Starter
Join Date: Jul 2015
Location: USA
Posts: 19
Upvotes: 0
Received 0 Upvotes on 0 Posts
Before I added the sconce the Light was connected to GFCI recep and switch and it work. Now I added a sconce light to the connection and sconce is flickering.

Here is how it was before adding the sconce light. One cable went from GFCI to light switch. It work as it should the light will turn on.

Name:  IMG_1657.jpg
Views: 1794
Size:  17.4 KB


The second image the top is how i currently have it connected and it works turning both lights on. I put in new wiring instead of 12/2 cable connected to power in cables i put 12/3 cable up to the second light and then 12/2 cable to junction box. The second image (bottom) is what I tried to do with the GFCI , light switch, and added light fixture. It works turning on the lights, but when off the sconce would start flickering.

Name:  IMG_1658.jpg
Views: 1767
Size:  21.3 KB


I don't understand how the top one work and the bottom one didn't.
 
Attached Images  

Last edited by knight3136; 08-02-15 at 06:17 PM. Reason: added picture
  #7  
Old 08-02-15, 05:48 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
None of your diagrams would work. My guess is you are misunderstanding how it was wired in the first place.

Based on what you have written was this how it was wired before you started?

Name:  Sw_Loopb-1_zps69e9ba8b.jpg
Views: 2282
Size:  19.5 KB
 
  #8  
Old 08-02-15, 06:14 PM
K
Member
Thread Starter
Join Date: Jul 2015
Location: USA
Posts: 19
Upvotes: 0
Received 0 Upvotes on 0 Posts
The original had a GFCI recep. So the wires from the switch loop above were not connected directly to switch but to the GFCI recep and then one red wire from top of the GFCI recep to the switch. Also I don't know how it was wire from the power in to the junction box of the GFCI since i disconnected the original 12/2 cable and instead of removing it and breaking the ceiling to the junction box, I just added a new cable and broke the wall to make a new route of the new 12/3 cable more directly to the same junction box.
 
  #9  
Old 08-02-15, 06:49 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
The original had a GFCI recep. So the wires from the switch loop above were not connected directly to switch but to the GFCI recep
That would have been wrong.

Does power come in at the original light or the switch. Once you tell us we can tell you how to wire it.
 
  #10  
Old 08-02-15, 09:30 PM
K
Member
Thread Starter
Join Date: Jul 2015
Location: USA
Posts: 19
Upvotes: 0
Received 0 Upvotes on 0 Posts
The power comes in from the original light.

This is how it was. I only had access to the junction box (box 1) with the GFCI recep and switch. Everything in light green I didn't have access to due to being hidden in the ceiling. I only had access to the light fixture junction box(box 2) which had 12/2 cable coming in with the power and connected to another 12/2 cable that went to box 1, everything in light green i didn't have access to and don't know it ran throughout the walls and ceiling or if there was some other connection between both junction boxes. I decided to disconnect this 12/2 going from box 1 to box 2, left it behind the walls and ceiling and inserted new 12/2 and 12/3 cables which were more direct (broke a new path in the ceiling) from one junction box to the other except I added another junction box (box 3) for the sconce fixture.

This was my original hook up.
Name:  Original GFCI.jpg
Views: 1774
Size:  15.0 KB

This is what I currently have and it works.

Name:  How I have it.jpg
Views: 1740
Size:  14.7 KB

But this is what I tried to do but it didn't work.

Name:  How I have it1.jpg
Views: 1758
Size:  16.1 KB
 

Last edited by knight3136; 08-02-15 at 10:45 PM.
  #11  
Old 08-02-15, 10:06 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
The power comes in from the original light.
Do you mean power comes in at the original light. If so then here is how to wire it:

Name:  BG.jpg
Views: 1786
Size:  20.5 KB

Name:  BG.jpg
Views: 1748
Size:  21.6 KB
 

Last edited by ray2047; 08-02-15 at 11:06 PM.
  #12  
Old 08-02-15, 11:06 PM
K
Member
Thread Starter
Join Date: Jul 2015
Location: USA
Posts: 19
Upvotes: 0
Received 0 Upvotes on 0 Posts
If ray is correct then I'm too late to do it. I already put up the tiles and seal them. I guess I will have to deal with not having the GFCI connected. Is it necessary to have one in your house? what were to happen if you don't have one?
 
  #13  
Old 08-02-15, 11:15 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
This was my original hook up.
Could not have worked that way. You have no wire returning power from the switch and you have the GFCI wired in series.
This is what I currently have and it works.
But the wiring is incorrect. Here is how it should be wired:

Attachment 54108

But this is what I tried to do but it didn't work.
It couldn't work. You have no wire returning power from the switch and you have the GFCI wired in series.
 
  #14  
Old 08-02-15, 11:34 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,415
Received 4,049 Upvotes on 3,632 Posts
Only has a switch loop. No receptacle possible next to the switch.
When you had one in there a tester would show it as ok but nothing would have worked properly.

Name:  flickering.jpg
Views: 1803
Size:  24.9 KB
This diagram is correct and only way to wire the circuit.
 
  #15  
Old 08-02-15, 11:38 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
By code all bathrooms are required to have one dedicated 20 amp receptacle circuit. Assuming you have either an unfinished basement below or attic above there is no reason to disturb the tile to run a new circuit.

You should really not try to do any more wiring till you understand how electrical circuits work. A good book is Wiring Simplified available at Amazon and in the electrical aisle of some Home Stores.
 
  #16  
Old 08-02-15, 11:49 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
While Pete is correct in post #14 about you being correct it is not the way you would normally do it. The red wire isn't needed.

Name:  Sw_Loopb-2_zps0955dcef.jpg
Views: 1901
Size:  28.6 KB
 
 

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