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jpettit
11-19-2008, 01:27 PM
Does anybody have any thoughts or experiences with this?

We use mostly fluorescent bulbs in our home, and I noticed a slight flicker (not on and off, but slightly dim) in them one night. Not sure if they always do that when larger things are turned on and of or whatever, but could it be from the blinky flashy of the light show drawing a large amount of power from the main panel or something else to be of concern?

Regular bulbs are fine, individual circuits are well under their ratings of their breakers. Nothing other than a few fluorescent bulbs do this.

ErnieHorning
11-19-2008, 02:40 PM
It’s normal. The wires and every connector in your house have some resistance and you will see it on something as sensitive to voltage as a florescent bulb. You’ll notice it mostly with your peripheral vision. I mostly notice the flickering when ‘Wizards in Winter” is playing.:D

jpettit
11-19-2008, 02:54 PM
LMAO! That's exactly what was playing. My wife first noticed it and started wondering if she made a mistake by letting me do this stuff and if I was going to burn our house down. It wouldn't be all the time, then the kids wanted to listen to the music inside while watching and ocurred to me that it may have been dimming to the music.

I was running everything on only 8 channels, so was wondering if it was way too much draw at one time. Like I said, my load should be fine as I planned the load pretty well and not every channel is on at the same time. I have boards and parts coming and adding 16 more channels, so should be able to lower the draw even more. Not sure if will lower the flickering though, but that song is what brought all of the cars out in front of our house last year.

I get the same thing in my garage's shop light if I start up the miter saw. Nothing like having it go black for a second with your hand so close to something that can take it right off. But those two items are on the same outlet.

Mufassa
11-19-2008, 03:08 PM
Is it cold in the house? I have seen that happen when they are cold its hard for them to start up...


--Greg

jpettit
11-19-2008, 03:23 PM
We keep the temp between 68 and 70. The lights that did it were on a hanging chandalier. Hangs from a vaulted ceiling and is near a patio door.

ErnieHorning
11-19-2008, 03:33 PM
Newer fluorescent lights aren’t as bad as they used to be. I have CFL’s that have about a ¼ second delay and then snap right on at full brightness. I have some for outside that turn on at below zero.

I also have lights in my garage that are rated at -20°F and they snap on immediately, even at below zero. They use the same T-40 bulbs but offer something like 95% increased brightness. I bought four to install in the garage attic and only needed two.

jpettit
11-19-2008, 03:37 PM
I have had my bulbs for quite a while. Some light outlets aren't so great for fluorescents and take over a minute to reach full brightness. Most of the newer lights that I have are instant on.

cm11599ps
11-30-2008, 10:22 AM
I had that problem too. I live in a hi ranch house where when you walk in the front door you're faced with 6 steps to go to the upper level and six steps to go down to the lower level. When we moved in there was an electric eye installed in there with a basic light fixture. This was a much better idea then using a 3 way switch.

Anyway, in time we decided to put a chandelier in there that would be attached to the electric eye. I put in the fluorescent bulbs too. The lights came on fine but there was a bit of a flicker with them. I ended up swapping them out for regular bulbs and haven't had a problem.

ErnieHorning
11-30-2008, 10:49 AM
The lights came on fine but there was a bit of a flicker with them. I ended up swapping them out for regular bulbs and haven't had a problem.There are florescent bulbs now that are labeled “dimmable”. They’re no more dimmable then the previous one’s, but they work consistently with TRIAC controllers. They come on nearly immediately and have no flicker. As far as dimming, they’re good for down to about 50%, maybe a little less.

oilcan73
12-01-2008, 01:50 PM
It's called a third harmonic and it's caused by an unbalanced load on the load center itself. Say you have 10 110v breakers on one side, and 10 on the other. if you had the same current draw on both sides, you would have a balanced flow. If you have several electronic items plugged in on one side of the load center, because of inrush current of power supplies, filters, ect. you wind up with an unbalance in current flow. Because almost all flouresent lights are of the rapid start type the freq. at which they "flouress"
is highly suceptable to small changes in current draw throughout your house. this is normal. Remember, the gagets we use, the flicker we get. I hope this helps.
-----Thomas

ErnieHorning
12-01-2008, 02:30 PM
It's called a third harmonic and it's caused by an unbalanced load on the load center itself.I beg to differ on this one. I could see it if we were switching inductive loads, but we’re switching incandescent lights, which for all practical purposes, is purely resistive. The wires in the walls not being perfect conductors will drop some voltage when heavy current is drawn through them. Depending on how long the wires are from the breaker panel, it’s not uncommon to see a drop of 5 to 10 volts with 15 amps of draw.

I do agree that if you’re drawing 100 or more amps for your entire display, then you should balance the load on both sides of the pole transformer. The same resistance problem will apply to the neutral wire coming in and you will see the voltage drop affecting the opposite phase.

The compact florescent bulbs, being as cheap as they are, have no voltage regulation so small voltage changes that last for several cycles will be detectable by the eye.

jpettit
12-01-2008, 03:15 PM
So we can all agree that the slight flickering of fluorescent bulbs is normal and on top of it all we get a free show inside the house. :p

g2ktcf
12-01-2008, 03:22 PM
So we can all agree that the slight flickering of fluorescent bulbs is normal and on top of it all we get a free show inside the house. :p


{{{{Applause}}}}}

oilcan73
12-01-2008, 03:23 PM
I am not saying that the light show load is causing this by itself, but the way the load is shared throughout the house. Electronics in general will cause this more than anything else. Please the attached .txt (This is from www.powershaver.com) At the Platform I work on, we deal with this on a constant basis. Manly because of constant cycle issues.

deplanche
12-01-2008, 03:28 PM
The shows usually look better with the inside lights off anyway. So take it as a reminder to turn off the lights.

bmcgeeny
12-01-2008, 07:36 PM
I beg to differ on this one. I could see it if we were switching inductive loads, but we’re switching incandescent lights, which for all practical purposes, is purely resistive. The wires in the walls not being perfect conductors will drop some voltage when heavy current is drawn through them. Depending on how long the wires are from the breaker panel, it’s not uncommon to see a drop of 5 to 10 volts with 15 amps of draw.

I do agree that if you’re drawing 100 or more amps for your entire display, then you should balance the load on both sides of the pole transformer. The same resistance problem will apply to the neutral wire coming in and you will see the voltage drop affecting the opposite phase.

The compact florescent bulbs, being as cheap as they are, have no voltage regulation so small voltage changes that last for several cycles will be detectable by the eye.

Yeah, what he just said.

In english I noticed it the minute my show started the first time. Only the CFL's in the house is it noticeable. No Edison bulbs flicker.