Light Bulbs Failing Simultaneously
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Lone Star Charles
New Member
I've always heard the old saying about leaving a light bulb on and making it last longer, but I've never really been able to verify that through experience. Does anybody have any references or sources for that claim?
Seems to me that an incandescent bulb with a 2,000 hour life will last about 83 days if left on continuously, but will last for about 250 days if it is only turned on for 8 hours per day. It will also use less power per day. This appears to me to be the better option.
Seems to me that an incandescent bulb with a 2,000 hour life will last about 83 days if left on continuously, but will last for about 250 days if it is only turned on for 8 hours per day. It will also use less power per day. This appears to me to be the better option.
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Jadnashua
Retired Defense Industry Engineer xxx
I'm an advocate of whole-house surge suppression. It can help those things where point of use ones (that are typically better, but protecting more sensitive equipment) are not possible. I've had one in my home for ages, and put one in my mother's after a surge fried both the circuit board in her refrigerator and the microwave. They certainly can't solve a direct strike or all problems, but they certainly can help. Power line spikes, if they get into electronics (cheap power supplies on things may not do a great job) eat away the junctions in the solid state components - they often don't fail immediately unless it is the BIG ONE, IOW, lots of little ones can act like a small chipping hammer over time damaging them as much as hitting it with a sledge once.
FWIW, many of the light switches in my house are Maestro dimmers. These always turn the lights on and off slowly (over maybe two seconds) and since most of the time, I don't need them on full, running them at less than full power saves both money and lengthens the bulb life (just make sure to use a bulb that can be dimmed). That series from Lutron can also work with as many as (I think it's up to) eight switches controlling a single lamp (say a hall light switch outside of each room) with only a 3-wire cable between them, so they are handy and versatile, but obviously, more than a simple switch.
FWIW, many of the light switches in my house are Maestro dimmers. These always turn the lights on and off slowly (over maybe two seconds) and since most of the time, I don't need them on full, running them at less than full power saves both money and lengthens the bulb life (just make sure to use a bulb that can be dimmed). That series from Lutron can also work with as many as (I think it's up to) eight switches controlling a single lamp (say a hall light switch outside of each room) with only a 3-wire cable between them, so they are handy and versatile, but obviously, more than a simple switch.
Bluebinky
Member
A loose neutral connection in a multi-wire circuit can cause higher than normal voltages. Probably not what's happening here, though.
LLigetfa
DIYer, not in the trades
I stand corrected.
DonL
Jack of all trades Master of one
Loosin
Loosing a Neutral can be a big problem.
You will be replacing more than just Light bulbs.
Loosing a Neutral can be a big problem.
You will be replacing more than just Light bulbs.
SAS
Member
It's nearly a month later and I just had the 2 bulbs in my garage door opener fail simultaneously. The lights are activated by a motion sensor so they were already on when I pressed the button to open the door. As soon as the motor started the bulbs both blew out.
In this case I would guess a voltage spike when the motor kicked in, but I can't say I understand how/why that would happen. Generally when a motor starts up the lights on the circuit dim.
In this case I would guess a voltage spike when the motor kicked in, but I can't say I understand how/why that would happen. Generally when a motor starts up the lights on the circuit dim.
LLigetfa
DIYer, not in the trades
Garage openers make a lot of vibrations and so there are special rough service bulbs made specifically for them.
Jadnashua
Retired Defense Industry Engineer xxx
I'll second the rough-service bulbs. YOu might want to consider LED or CFL bulbs for this, but some are better than others for vibrations. When a bulb gets older, if you were to look at the filaments under a magnifying glass, you'd notice that over time, parts are thinner than others, and vibrations can make them break at that weak point. Rough service bulbs tend to have either thicker filaments, or more supports, or both. Compare an old incandescent bulb with a new one, and the older one will tend to have a blackish haze on it...that's the metal from the filaments that boiled off and redeposited on the cooler glass globe.
It also may be time for some service on the opener itself...springs can get weak with age, some rollers need grease (some don't) but regardless, check their bearings. If the springs get weak, the whole opener will have to work harder and may vibrate more, so you may need to adjust them.
It also may be time for some service on the opener itself...springs can get weak with age, some rollers need grease (some don't) but regardless, check their bearings. If the springs get weak, the whole opener will have to work harder and may vibrate more, so you may need to adjust them.
LLigetfa
DIYer, not in the trades
If the garage is unheated, CFL are not the best choice as they have trouble starting in the cold.
SAS
Member
What I still continue to find unusual is that both bulbs burned out at the same time. It seems unlikely that vibrations would cause exactly the same amount of deterioration so that both bulbs reached the breaking point simultaneously.
SAS
Member
I can check with a meter, but I don't see how that would be the cause in this case. The motor and lights are wired together and there is a single plug that powers both. Both lights burned out as soon as the motor kicked in, and in this case the motor can't be on a different pole in the panel than the lights.
OK... Sorry. I failed to catch the part that these two bulbs are part of the garage door opener, and therefore therefore are powered by the same pair. The vibration from the motor starting and the opener housing jumping moving the filaments enough to short things out in each bulb seems to be the best match to the symptom then.
The cure is LED bulbs. They are maybe $10 each, and will not be delicate.
The cure is LED bulbs. They are maybe $10 each, and will not be delicate.
SAS
Member
Well you were right about vibration being the problem. One was indeed burned out, but it had been loosened enough that it corroded the contact. The other bulb had just loosened to the point that it was no longer making contact. I'm still amazed that both stopped at the same time, but it clearly had nothing to do with a voltage spike and is totally unrelated to any other bulb issues I've had.
Curiously, CFL bulbs flicker in this opener. I've had that with dimmers before, but there must be some electronic circuitry involved that causes that behavior.
Jadnashua
Retired Defense Industry Engineer xxx
It's possible that the opener uses an electronic switch to turn the lamps on rather than something like a relay, and that could spell early death to either LED or CFL bulbs. A CFL, depending on the design, literally turns on and off as the a/c power cycles...if there's a triac or something similar in the circuit rather than just being hooked directly to the sinewave power, you'll notice the on/off cycles. Most LED designs will have a small capacitor in there to keep the voltage more constant so they normally would stay on and not exhibit flicker.
At 60-cycles, most people can't see a florescent turning on and off as the power runs through the zero point, but if that point is expanded because of a diode being in there, the time it's off will be longer, and you'll notice the flicker. My guess is that if you put a meter on the bulb contacts and measured verses directly on the power line, you'd see the bulb socket's voltage is a little lower - a side-effect of the electronic switch. It probably wouldn't help the CFL, either.
At 60-cycles, most people can't see a florescent turning on and off as the power runs through the zero point, but if that point is expanded because of a diode being in there, the time it's off will be longer, and you'll notice the flicker. My guess is that if you put a meter on the bulb contacts and measured verses directly on the power line, you'd see the bulb socket's voltage is a little lower - a side-effect of the electronic switch. It probably wouldn't help the CFL, either.
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