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    AKaeTrue's Avatar
    AKaeTrue Posts: 1,599, Reputation: 272
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    #1

    Sep 19, 2008, 02:56 PM
    Light bulbs blowing out
    I've read other threads concerning this matter but I don't understand how to apply the information to my problem.

    I make sure the watt/volts are at or (mostly under) the recommended limit.
    I stopped replacing every bulb and only have a few
    Throughout my house, enough to get by to see at night, but they blow within a few weeks and it only happens when you turn on the light.
    There will be a flash and a pop sound when it happens.

    Light bulbs use to last for years then all of a sudden they started blowing and it never stopped.

    Any suggestions on what might be causing it and if it's something that requires an electrician?

    Thanks.
    KISS's Avatar
    KISS Posts: 12,510, Reputation: 839
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    #2

    Sep 19, 2008, 05:08 PM
    Bad lot. Switch brand of bulbs for a while. Happens.
    Stratmando's Avatar
    Stratmando Posts: 11,188, Reputation: 508
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    #3

    Sep 19, 2008, 05:30 PM
    Could be loose neutral, If you wanted to verify, turn off all breakers but that circuit. Then turn on light. If it doesn't blow, I would suspect the neutral.
    I would check evry connection from meter to panel, all neutrals in panel, and all neutrals on that and shared circuit neutral.
    AKaeTrue's Avatar
    AKaeTrue Posts: 1,599, Reputation: 272
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    #4

    Sep 19, 2008, 06:53 PM
    Thanks to both of you.
    I've been having this problem for probably a year.

    It happens in every room and hallway within my home, with the exception
    Of ceiling fans that use those tiny halogen bulbs.

    I did try different brands at first but that didn't work.

    Since the bulb doesn't blow every time the light is turned on, would
    The breaker/circuit test work to verify? Bulbs blow about every few weeks
    And you never know when it's going to happen.

    I did have someone check it out when it first started, he checked (I don't know what he checked),
    But told me to watch the watt/volt thing... so I have been, but it still kept happening.
    hkstroud's Avatar
    hkstroud Posts: 11,929, Reputation: 899
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    #5

    Sep 20, 2008, 05:50 AM

    Do you have a volt meter? If so, check your voltage, could be that you have a higher than usual voltage.
    Stratmando's Avatar
    Stratmando Posts: 11,188, Reputation: 508
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    #6

    Sep 20, 2008, 05:53 AM

    They do make 130 volt bulbs, may help here.
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #7

    Sep 20, 2008, 06:14 AM

    To eliminate any guessing, my suggestion is to hire a good "service" electrician with good troubleshooting skills and has direct access to and knowledge of power recording instruments.

    The strategy will be to connect at least two recorders for a period, no less than a week, possibly up to a month.

    One recorder should be at the main service panelboard, and another connected out at the end of one of the circuits affected that has experienced the lamps burning out prematurely.

    The result recordings will show a numerical and graphical image of the actual voltage and amperage, along with any voltage sags and swells ( dips and spikes in laymen terms) that may be occurring.

    This will be similar to having an EKG done on your heart, measuring and recording any (depending on the specs and quality of the power recorder) unusual events, such as consistent higher than normal voltage, or voltage swells and transient spikes, that may be damaging your lamps.

    While the lamps may seem to be the most noticeable and frustrating event you have, and not too costly to deal with, what needs to be considered is damage being done to other items in the home, such as refrigerators, motors, and electronics.

    Having one recorder at the service panel will help isolate if the incoming power is the cause, and having one at the end of a problematic branch circuit will help identify if the problem is in the building, such as the loose neutral Strat mentions. To help identify this problem, note which circuit(s) the lamps are being affected.

    You may find that the incoming voltage, while still within tolerance, is normally and consistently high. Standard voltage in USA supplied by utility companies is 120 and 240 volts. Each utility lists in their the tolerances dictated by Public Utilities Commission, typically +/- 5%.

    120 volts plus 5% is 126 volts. Incandescent lamps are very susceptible to premature burnout when subjected to higher than rated voltage.

    Did the electrician suggest to use 130 volt rated lamps?

    The wattage issue you mention is probably something similar to that he found a 100 watt lamp in a fixture only rated for 60 or 75 watts maximum. This is not going to help much, as the max wattage rating has to do with the heat created by over size lamps. While entrapped heat is one culprit that lessens incandescent lamp life, this is not as frequently noticeable as the events you are incurring.

    Areas or buildings close to utility substations are typically subjected to consistent higher voltages,and still within industry tolerances. 130 volt rated lamps help deal with this issue.

    Consumer Note, most "Long Life" light bulbs are really 130 volt lamps. Since most homes get 120 volts if lucky, usually less, lamps will last longer.

    So, in my opinion, without doing the "EKG" as I explained, all that is happening is guessing and looking for the needle in the haystack.
    KISS's Avatar
    KISS Posts: 12,510, Reputation: 839
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    #8

    Sep 20, 2008, 06:19 AM
    I think I might agree with that you could have a loose mains connection say where the wires connect to the mast head or even an open neutral. The mains should be checked by a qualified electrician as well as for loose connections in the fuse panel.

    Higher than normal voltages can be looked at too, but I doubt it.
    AKaeTrue's Avatar
    AKaeTrue Posts: 1,599, Reputation: 272
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    #9

    Sep 20, 2008, 06:22 AM

    I don't have a volt meter on hand to check it with but I know someone who does and I'll see about that today.

    I'll also check out the 130 volt bulbs.

    Thanks to both.
    hkstroud's Avatar
    hkstroud Posts: 11,929, Reputation: 899
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    #10

    Sep 20, 2008, 06:40 AM

    Could someone share the logic of how a loose neutral shortens bulb life? I can see it if the loose connection is at the fixture and causing excessive heat but I would think that a loose connection elsewhere would cause a reduced voltage and amperage but that would cause extended bulb life.
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #11

    Sep 20, 2008, 06:56 AM

    AK, using a standard volt meter will only help identify the consistent higher than normal voltage, as it will only show what the voltage is at the time of the reading.

    Since Kiss doubts high consistent voltage, looks like I need to explain further.

    I do not mean to imply that this is your problem. I was only expanding on that one issue to help explain a popular problem that has popped up in areas that had not had problems in the past, but with the utility companies adding distribution lines and substations due to higher demand in the last few years, more and more areas are now getting normally higher voltages.

    To expand further, measuring and recording the volts over time will help narrow down the more likely loose connection, loose neutral issue, poor utility connections, that may be related to your home.

    To thoroughly check all connections, both the utility company and an electrician should be on site together, utility to check the transformer and incoming lines connections, and allow the electrician to check inside the electric meter, along with the panelboard and grounding.

    If your located near any industrial plants or commercial businesses, for example, this can cause voltage swells that are not consistent, and rarely measurable with just a standard voltage meter.

    What needs to be mentioned, loose connections that cause lamps burning out will be directly related to loose neutral connection, but this will also affect everything in the home, due to high abnormal voltages being impress on all circuits and devices, and usually more noticeable damage to other devices and appliances.

    Most loose connections other than loose neutral will cause lights to flicker, which means that lights will be going off and on, not just stay one but get brighter (which you don't mention) and burn out.

    Sure, someone can check all visible connections, still missing hidden connections, and hopefully trip over the fault or cause. And sit back and wait hoping the problem was solved.

    Not just for you, but other readers with similar problems, is why I suggest this systematic approach to help eliminate hoping and guessing.

    Please get back with any and all results.
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #12

    Sep 20, 2008, 07:10 AM
    Quote Originally Posted by hkstroud View Post
    Could someone share the logic of how a loose neutral shortens bulb life? I can see it if the loose connection is at the fixture and causing excessive heat but I would think that a loose conection elsewhere would cause a reduced voltage and amperage but that would cause extended bulb life.

    HK, I would have to draw out a diagram to show quickly and exactly what happens when a loose shared neutral, the key word is shared.

    But let me see what I can do with words.

    If you have two circuits in one cable and both share the neutral, if the neutral breaks, or opens, this leaves each circuit with no 120 volt return. But , here is where a diagram would help, a light bulb, and any other outlet or device, on the circuit can see up to 240 volts impressed on it. The voltage in one circuit seeks a return, and flows through one lampor device, and connects to the other circuit. Usually the voltage one one circuit can be 180 volts, and 60 volts on the other.

    This is all depending on how many lamps or devices are on and letting voltage through, the impedance of each, etc.

    While a loose neutral can cause abnormal voltage on one circuit, the bulb gets real bright fast, and burn out. But what is usually noticed is on the other circuit the bulbs get very dim.

    Keep in mind, the service feeder from the utility is a shared neutral. If this opens, the entire home, and every light bulb and appliance can be subjected to high abnormal voltages, one one 120 leg, and will always have the other leg with low abnormal voltage.

    So, how did I do with words? I have no patience with diagrams, such as yours I have seen. Nice job on those, pictures tell a thousand words.
    AKaeTrue's Avatar
    AKaeTrue Posts: 1,599, Reputation: 272
    Ultra Member
     
    #13

    Sep 20, 2008, 07:40 AM
    Quote Originally Posted by tkrussell View Post
    To eliminate any guessing, my suggestion is to hire a good "service" electrician with good troubleshooting skills and has direct access to and knowledge of power recording instruments.

    The strategy will be to connect at least two recorders for a period of time, no less than a week, possibly up to a month.

    One recorder should be at the main service panelboard, and another connected out at the end of one of the circuits affected that has experienced the lamps burning out prematurely.

    The result recordings will show a numerical and graphical image of the actual voltage and amperage, along with any voltage sags and swells ( dips and spikes in laymen terms) that may be occurring.

    This will be similar to having an EKG done on your heart, measuring and recording any (depending on the specs and quality of the power recorder) unusual events, such as consistent higher than normal voltage, or voltage swells and transient spikes, that may be damaging your lamps.

    While the lamps may seem to be the most noticeable and frustrating event you have, and not too costly to deal with, what needs to be considered is damage being done to other items in the home, such as refrigerators, motors, and electronics.

    Having one recorder at the service panel will help isolate if the incoming power is the cause, and having one at the end of a problematic branch circuit will help identify if the problem is in the building, such as the loose neutral Strat mentions. To help identify this problem, note which circuit(s) the lamps are being affected.

    You may find that the incoming voltage, while still within tolerance, is normally and consistently high. Standard voltage in USA supplied by utility companies is 120 and 240 volts. Each utility lists in their the tolerances dictated by Public Utilities Commission, typically +/- 5%.

    120 volts plus 5% is 126 volts. Incandescent lamps are very susceptible to premature burnout when subjected to higher than rated voltage.

    Did the Perry Farrell suggest to use 130 volt rated lamps?

    The wattage issue you mention is probably something similar to that he found a 100 watt lamp in a fixture only rated for 60 or 75 watts maximum. This is not going to help much, as the max wattage rating has to do with the heat created by over size lamps. While entrapped heat is one culprit that lessens incandescent lamp life, this is not as frequently noticeable as the events you are incurring.

    Areas or buildings close to utility substations are typically subjected to consistent higher voltages,and still within industry tolerances. 130 volt rated lamps help deal with this issue.

    Consumer Note, most "Long Life" light bulbs are really 130 volt lamps. Since most homes get 120 volts if lucky, usually less, lamps will last longer.

    So, in my opinion, without doing the "EKG" as I explained, all that is happening is guessing and looking for the needle in the haystack.
    You know, I've been having problems with my refrigerator for a while now.
    I never thought it could be linked.

    The service guy never said anything about 130 volt bulbs that I can recall.
    He actually came out to fix the dryer plug because it was sparking.
    So when he was here, he also took a look around and checked what ever he checked.
    He told me to always stay at or below the watt/volt requirements for a fixture or lamp.

    I do live 1 block away from high voltage power lines and I believe there is a substation nearby, if there is, it's been here since I've lived here.

    I did a little research though after I read your post and
    A new substation and a 3 mile, 100,000 v transmission line opened up last summer 2007 about 10 miles away from where I live.

    This would have been around the time I started having problems but since the addition isn't serving my area would it still pose a problem?

    I think my neighbor said her bulbs are blowing too in a conversation a while back. I'll have to ask her again to make sure.

    Thanks for all your info and suggestions.

    Edit, I notice there was more written that I haven't had a chance to read yet but I will as soon as I get a chance. Thank you everyone.
    donf's Avatar
    donf Posts: 5,679, Reputation: 582
    Printers & Electronics Expert
     
    #14

    Sep 20, 2008, 08:51 AM

    Is your refrigerator on an independent circuit or is it on one of the two or more required 20 amp circuits for the kitchen counter top?

    If you are talking about multiple branch circuits failing (more than two branch circuits) in similar ways then you are netting it down to a Power Company problem or a main panel problem as TK indicated above.
    KISS's Avatar
    KISS Posts: 12,510, Reputation: 839
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    #15

    Sep 20, 2008, 01:44 PM
    Hk:

    Loose connections shock the filament especially at initial turn on. At that time the resistance of the tungsten filiment is about 10 times less than what it is when the bulb is operating.
    hkstroud's Avatar
    hkstroud Posts: 11,929, Reputation: 899
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    #16

    Sep 20, 2008, 02:56 PM

    KISS,
    Are you saying that there can be a spike in curent flow in the filament at initial turn on, if there is a poor neutral connection?

    I'm thinking, I'm thinking.

    I guess I'm thinking like water hammer in a plumbing pipe when a fast acting valve shuts off (bad neutral connection being fast acting valve) ?
    EPMiller's Avatar
    EPMiller Posts: 624, Reputation: 37
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    #17

    Sep 20, 2008, 04:51 PM
    Quote Originally Posted by hkstroud View Post
    KISS,
    Are you saying that there can be a spike in curent flow in the filament at initial turn on, if there is a poor neutral connection?
    <snip>
    I guess I'm thinking like water hammer in a plumbing pipe when a fast acting valve shuts off (bad neutral conection being fast acting valve) ?
    HK,
    Not exactly like water hammer. A light bulb at turn ON has a low resistance and so there will be a SMALL current spike, but as the filament heats up the current is reduced by the increasing filament resistance. I should try to measure the spike on some high wattage lamp and see if I can catch it. It will be extremely fast. There is no 'hammer' at turn OFF because electricity has no weight, no momentum or kinetic energy. Contact flashover is not caused by momentum but by voltage potential and the resistance of the insulating medium (air usually) between the switch contacts. Go look at some of the videos on YouTube of 500kV switches being opened!

    You probably know this, but for those that are reading to learn: Motors do have a current spike that is measurable if you have a recording DVM. There is a LRA (Locked Rotor Amps) spec on the nameplate. This is the inrush current that reduces to the running current when the motor gets up to speed. I often check that when troubleshooting air conditioners or refrigerators. FLA (Full Load Amps) are what the motor draws when running at... full load.

    Oh, yeah. I needed one of those left handed widgets the other day, can't remember what for, but I know I was fresh out.

    EPM
    KISS's Avatar
    KISS Posts: 12,510, Reputation: 839
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    #18

    Sep 20, 2008, 04:56 PM

    There is a temperature coeffecient of resistance. It's just about 10X going from room temp to maybe 2000 deg F. Hence the spike.

    Watter hammer would be an analogy for a loose connection sice Voltage is analogous to pressure and Amperes is analogous to flow and resistance is analogous to the diameter of a pipe.
    Arcing would definitely be an analogy to water hammer.
    EPMiller's Avatar
    EPMiller Posts: 624, Reputation: 37
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    #19

    Sep 20, 2008, 05:32 PM
    Quote Originally Posted by KeepItSimpleStupid View Post
    <snip>
    Watter hammer would be an analogy for a loose connection sice Voltage is analogous to pressure and Amperes is analogous to flow and resistance is analogous to the diameter of a pipe.
    KISS,

    I respectfully disagree. As a simple explanation for a beginner, yes, electricity can be described in water flow terms, but the analogy breaks down when explaining in more detail. The water analogy only holds well for resistive DC circuits.

    Electrically, a loose connection increases resistance. Resistance dissipates energy but it doesn't slow the speed down. In a purely resistive network, it would just add to the load and decrease the current by it's percentage of the total load. In a circuit with a reactive component (a motor for example) the loose connection will cause a drop in voltage to the motor which will respond by drawing more current until it achieves a steady state for it's load. (I won't go into voltage and current phase angles, counter EMF and all that, I'm not good enough at explaining all that in a concise way.) Back to our motor. As the motor draws more current, the loose connection heats up more (it has a negative temperature coefficient) until something fails. Yes, I know, if you decrease the pipe size the flow speed has to increase to maintain volume, but electricity doesn't change speed. And water doesn't deal with reactive or inductive loads like AC electricity.

    Arcing would definitely be an analogy to water hammer.
    Here I strongly disagree. Water hammer is caused by kinetic energy. Electricity has no such property in the realm we deal with. Arcing is just an electrical flow through a resistance.

    I am open to correction if I am wrong and someone can point me to where I can learn more.

    EPM
    KISS's Avatar
    KISS Posts: 12,510, Reputation: 839
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    #20

    Sep 20, 2008, 06:08 PM
    OK, your turn. If I applied a large AC voltage say 3000 V p-p and at 10 Hz to small air gap in series with a 3000 V light bulb. What might happen? Wouldn't the lamp blink?

    Loose connections do just that initially.

    Loose connections will EVENTUALLY develop into a high resistance due to oxide buildup. That high resistance acts as a heater based on I^2R and eventually bad things happen, but before we get to that point it's a rapid on/off switch toggled by vibration and temperature either internal or external.

    Your right, in the limit at t approaches infinity it is usually a high resistance.

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