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#222769 10/23/24 10:02 PM
Joined: Mar 2004
Posts: 829
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BigB Offline OP
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Why do they always call me on this stuff? This time it's a friend who lives in town so eventually I'll be able to drive up to his place if necessary. meanwhile here is what is happening. House is a 2008 build. He has a ceiling fan and a porch light on a stack switch. For a couple of months, every time the ceiling fan is switched on the 65 inch flat screen TV drops out for 3 seconds, but switching the light doesn't affect it. He swapped the light and fan on the stack switch and the problem stayed the same, the fan still interrupts the TV. All of this is on the same 15 amp non-AFCI non multiwire branch circuit.

I was pretty sure it was going to be an issue with the stack switch as it is probably one of those multi-configurable ones but what happened next throws that assumption out the window.

Yesterday they noticed when the doorbell rings, the TV cuts out for the same 3 seconds, yet the doorbell transformer is on the garage lighting circuit on the other side of the house! A totally separate circuit! (I had him shut the TV circuit off and the door bell still works)

Next I told him to plug a lamp into the duplex that the TV is plugged into and watch it. When switching on the ceiling fan the TV again drops out for 3 seconds but the lamp doesn't even flicker. Same result with the doorbell.

Next I told him to plug the TV into an extension cord on a different circuit. When he does this, the TV is unaffected by both the ceiling fan or the doorbell.

The only thing I can come up with is the TV is seeing something is doesn't like on that circuit, but the doorbell transformer on a different circuit really throws a monkey wrench in the works.

He's not good with a meter nor does he own one so I could drive up there and measure voltage at the TV receptacle but not sure if my old Fluke 27 would catch a nanosecond drop. He did open the panel and check for loose screws on the breakers and the neutral bus.

He texted me a photo of the (Homeline) panel, there are no multiwire branch circuits and there are 3 AFCIs for the 3 bedrooms, the living room and garage are both on separate circuits with regular breakers.

Any ideas?

Last edited by BigB; 10/23/24 10:05 PM.
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BigB #222770 10/25/24 10:07 AM
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BigB Offline OP
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I asked him this morning to see if the TV and the door bell circuits are on the same leg of the service. He's pretty sure they were opposite each other in the panel meaning they would both be on the same leg. If so, I will have him try plugging the TV into a different circuit on that same leg and see if the problem persists. Just trying different things to eliminate what we can. If we find out everything it isn't maybe we will be left with what it is.

BigB #222771 10/30/24 11:46 AM
Joined: Apr 2002
Posts: 7,413
Likes: 8
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If the circuits are on the same phase (leg), try swapping the breaker to the other phase.

The 'start-up' for the fan, and possibly (likely) the 'inrush' to the doorbell transformer (stop laughing) can cause a brief sag/spike/drop on the phase (leg) and mess with the TV electronics.

My best guess!


John
BigB #222850 04/28/25 09:22 PM
Joined: Feb 2004
Posts: 1,440
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Are the doorbell xfmr and the ceiling fan on the same circuit? I'm wondering if there's a box where these circuits meet someplace and they accidentally were crossed?

How old is the TV? Could it have a capacitor that's "kinda" working but on the weak side?

Are there any dimmer switches that the fan and/or TV outlet might be tied into?

Have other motor loads been tried on the same circuit as the TV? (Plug a vacuum cleaner into the TV duplex and see if the same issue occurs?)

Cheap ceiling fans tend to be *noisy* when run off of external fan controllers at lower speeds (The kind that hide in the ceiling fan canopy.) but the doorbell is throwing off my theories....

Lostazhell #222851 04/29/25 09:45 AM
Joined: Mar 2004
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BigB Offline OP
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Originally Posted by Lostazhell
Are the doorbell xfmr and the ceiling fan on the same circuit? I'm wondering if there's a box where these circuits meet someplace and they accidentally were crossed?

How old is the TV? Could it have a capacitor that's "kinda" working but on the weak side?

Are there any dimmer switches that the fan and/or TV outlet might be tied into?

Have other motor loads been tried on the same circuit as the TV? (Plug a vacuum cleaner into the TV duplex and see if the same issue occurs?)

Cheap ceiling fans tend to be *noisy* when run off of external fan controllers at lower speeds (The kind that hide in the ceiling fan canopy.) but the doorbell is throwing off my theories....


Funny you should ask. I still haven't gone out there and he didn't get back to me on my questions but they did replace some receps and he claimed that the new receps fixed the problem. But then just last week he called back and said that he was mistaken, the new receps did not fix anything and he is back to square one.

Being as I'm retired and ready to take a Summer trip here soon I won't be able to visit the house for a month or so. I'm suspecting the TV is most likely over-sensitive but I plan to do some "process of elimination" testing by moving stuff around.

BigB #222875 07/06/25 08:27 PM
Joined: Dec 2024
Posts: 4
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New Member
Originally Posted by BigB
Why do they always call me on this stuff? This time it's a friend who lives in town so eventually I'll be able to drive up to his place if necessary. meanwhile here is what is happening. House is a 2008 build. He has a ceiling fan and a porch light on a stack switch. For a couple of months, every time the ceiling fan is switched on the 65 inch flat screen TV drops out for 3 seconds, but switching the light doesn't affect it. He swapped the light and fan on the stack switch and the problem stayed the same, the fan still interrupts the TV. All of this is on the same 15 amp non-AFCI non multiwire branch circuit.
Sounds like you’re dealing with brief voltage sag or EMI spikes when the fan or doorbell transformer starts—but only on that specific circuit leg—causing your TV to reset. Swapping the breaker to the opposite phase or testing the TV on a different circuit (as you did with the extension cord) confirms it’s a circuit issue, not the TV. To prevent this, isolating or redistributing those motor/transformer loads is key. For consistent power stability, consider quality power‑management solutions like those from Ovaga Technologies. Let me know if you want to know more.
I was pretty sure it was going to be an issue with the stack switch as it is probably one of those multi-configurable ones but what happened next throws that assumption out the window.

Yesterday they noticed when the doorbell rings, the TV cuts out for the same 3 seconds, yet the doorbell transformer is on the garage lighting circuit on the other side of the house! A totally separate circuit! (I had him shut the TV circuit off and the door bell still works)

Next I told him to plug a lamp into the duplex that the TV is plugged into and watch it. When switching on the ceiling fan the TV again drops out for 3 seconds but the lamp doesn't even flicker. Same result with the doorbell.

Next I told him to plug the TV into an extension cord on a different circuit. When he does this, the TV is unaffected by both the ceiling fan or the doorbell.

The only thing I can come up with is the TV is seeing something is doesn't like on that circuit, but the doorbell transformer on a different circuit really throws a monkey wrench in the works.

He's not good with a meter nor does he own one so I could drive up there and measure voltage at the TV receptacle but not sure if my old Fluke 27 would catch a nanosecond drop. He did open the panel and check for loose screws on the breakers and the neutral bus.

He texted me a photo of the (Homeline) panel, there are no multiwire branch circuits and there are 3 AFCIs for the 3 bedrooms, the living room and garage are both on separate circuits with regular breakers.

Any ideas?

Sounds like a voltage sag or EMI issue, possibly poor neutral or shared grounding path affecting sensitive TV circuitry.


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