# blowing out light bulbs



## trucker

I am trouble shooting an electrical system that is in a 30+ year old res. home. The owner is complaining about going through a lot of light bulb. My first thought was bad neutral. I have already cleaned up some nasty looking junction boxes in the attic. Does anyone have any other ideas of what may be causing bulbs to blow? I did notice one double gang junction box in the attic that has 8 romex 12-2 going into it. White and black wires are separated but not all are wire nutted together.(6 neutrals under one wire nut and the other 2 neutrals in another wire nut, same with the hot legs).


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## JTMEYER

The circuit my be double fed somewhere giving it 240, like a miswired 3 way switch circuit.


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## sparks134

I just got a headache...


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## 480sparky

Use quality lamps, not the cheapies the grocery stores sell. 

Try 130v lamps.

Check the tab in the bottom of the socket. If it's crammed down into the socket, the lamps may not make good contact and create excessive heat. Turn the power off and pull the tab out to a 30° angle.

Vibration may be a problem. Are the doors that get slammed a lot nearby, or are the lights under a child's room?

Believe it or not, there is a 'correct' way to install a lamp. Turn the lamp enough for the threads to hold it, turn the power on, and continue turning the lamp until it lights, then ¼ turn more.

Check the circuit and the panel for over-voltage. If there's an intermittent loose neutral, it could cause high voltages.


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## BuzzKill

check N's, call poco to run a system check on xfmr and install a surge protector, in that order.


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## tduncanlu1077

maybe there is too much load on the set of neutrals. put an amprobe on it and tell us what it says


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## MDShunk

Use 130V lamps

Check for vibration

Check the integrity of the lampholder sockets.

Quit fooling around with neutrals that aren't part of the service or a MWBC, because they are not and and never will be your problem.


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## tduncanlu1077

MDShunk said:


> Use 130V lamps
> 
> Check for vibration
> 
> Check the integrity of the lampholder sockets.
> 
> Quit fooling around with neutrals that aren't part of the service or a MWBC, because they are not and and never will be your problem.


 absolutley right, like slingblade with the empty gas tank


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## Dennis Alwon

99% of the time the homeowner is using 120V bulbs from home depot or the grocery stores. Remember the power company often delivers 122- 124V. Those bulbs won't last 2 weeks.

Make sure they use 130V, as already mentioned, and that they are not oversizing the bulb in the fixtures. A fixture rated 60 watts will blow out 100 watt bulbs in no time.


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## sparky.jp

Another possible suggestion to the homeowner: install dimmer switches, the ones which require you to start dim (I like the GE toggle-style ones). This will significantly extend the life of the bulbs since the cold filaments will not be slammed with the high current at power-on.

When I was a kid, my dad remodeled our kitchen in 1970, installing four can lights over the counters with 150W floodlamps and rotary dimmers. Those bulbs, which got a lot of use, lasted for years and years. I think when we sold the house last year, one of the four bulbs was still original (how long has it been since ITT made light bulbs?). I remember that in the late 70s, one of the bulbs blew out when the dimmer failed and gave the bulbs full voltage when we turned it on.


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## bobelectric

I agree with 480 Sparky.​


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## HARRY304E

sparky.jp said:


> Another possible suggestion to the homeowner: install dimmer switches, the ones which require you to start dim (I like the GE toggle-style ones). This will significantly extend the life of the bulbs since the cold filaments will not be slammed with the high current at power-on.
> 
> When I was a kid, my dad remodeled our kitchen in 1970, installing four can lights over the counters with 150W floodlamps and rotary dimmers. Those bulbs, which got a lot of use, lasted for years and years. I think when we sold the house last year, one of the four bulbs was still original (how long has it been since ITT made light bulbs?). I remember that in the late 70s, one of the bulbs blew out when the dimmer failed and gave the bulbs full voltage when we turned it on.


Sylvania bought out ITT back in the 80's..


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## Big John

Dennis Alwon said:


> ...A fixture rated 60 watts will blow out 100 watt bulbs in no time.


 That's a new one to me. You figure the 60 watt fixtures aren't designed to dissipate heat as well, and as a result the lamps run hotter...? :confused1:

-John


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## knothole

In our neck of the woods the poco tends to run the voltage a little high 124v-127v. A 120 volt bulb will last about 6-8 weeks and a 130 volt bulb will last as long as a year, in some cases.


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## FES

I ran into that problem last year in a house that was less than 10 years old. They were going through light bulbs like candy. POCO checked the system and the only thing they found was high resistance @ ground rod. During the time of light bulb issues they had some electronic equipment to go "out." I installed another ground rod and surge protection @ the meter. That solved their problems.


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## guest

FES said:


> I ran into that problem last year in a house that was less than 10 years old. They were going through light bulbs like candy.* POCO checked the system and the only thing they found was high resistance @ ground rod. During the time of light bulb issues they had some electronic equipment to go "out." I installed another ground rod and surge protection @ the meter. That solved their problems.*


No you did not solve the problems, the extra ground rod is helping to cover up a bad/open neutral issue. 

Don't be surprised to get a repeat call (or not since I am willing to bet the problem had come back already.)


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## FES

All neutrals were checked from the meter panel through all devices. POCO checked them on their side also. I'm confident they checked their side because the engineer over that work order is someone I know and see all the time. As far as the homeowner....I see her on occasion and I always ask and they have had no problems since.


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## guest

Sorry but I still say you didn't solve the problem...the fact that it went away after you added the ground rod is the giveaway. Now if you measured the current on the GEC and it was zero or very close to it I would be satisfied that the POCO did indeed fix the problem (which I am positive was/is on their end). But based on the info given (and the POCO claiming they found nothing on their end) I am willing to bet you will have substantial current on that GEC. 

Did you actually watch and see the POCO check their side? If not I wouldn't beleive them for an instant, friend or not. Did that engineer actually do the work? If not then you and he are taking the word of the crew..and lots of posters here can attest to how reliable that word really is. :whistling2:

EDIT: Prime example of how POCO's handle things found here:

http://www.electriciantalk.com/f29/poco-leaves-customer-dark-19616/

I'm not trying to bust your chops, but over the years I have seen and dealt with enough of these situations to know that unless you ride the POCO's crew hard they will NOT exert a lot of effort in finding open neutral problems. In more than one case where the neutral was completely disconnected/broken it took the POCO DAYS to fix it, because the grounding electrode system was keeping the voltage in check close enough to not fry things. This is based on personal experience. 

I would not have left that job until I was positive everything was checked properly, based on how a second rod apparently corrected the problem.


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## Dennis Alwon

mxslick said:


> No you did not solve the problems, *the extra ground rod is helping to cover up a bad/open neutral issue. *


I seriously doubt that a rod would cover up a bad neutral, but I agree adding a rod would do nothing to alleviate the problem. I bet the poco either fixed the problem unknowingly or they wouldn't own up to it being their problem and fixed it quietly.


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## MDShunk

Dennis Alwon said:


> I seriously doubt that a rod would cover up a bad neutral, but I agree adding a rod would do nothing to alleviate the problem. I bet the poco either fixed the problem unknowingly or they wouldn't own up to it being their problem and fixed it quietly.


I've seen many municipal water pipe bonds cover up a completely open neutral. You never discover it until you start blowing up anything connected to the cable TV in the neighboring houses.


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## Dennis Alwon

MDShunk said:


> I've seen many municipal water pipe bonds cover up a completely open neutral. You never discover it until you start blowing up anything connected to the cable TV in the neighboring houses.


yeah but that's very different from a ground rod. I can see municipal water doing the job but not a rod.


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## hardworkingstiff

FES said:


> POCO checked them on their side also.


I just happened to go next door to ask my neighbor a question at the same time PoCo showed up. I asked them if they had a problem. They said the lights would flicker. PoCo came and said everything was fine. Being I'm a pushy kind of guy, I asked my neighbor to run their hair dryer while we checked voltage and sure enough, one phase dropped (H-N) and the other went up (H-N). I told PoCo they had a neutral issue coming in (we were checking voltage at the meterbase) and the service man said everything was fine. We "discussed" it for a couple of seconds and after I told him this kind of problem can burn up electronic equipment he decided to get his tester and sure enough, confirmed a neutral problem. It took them about 4 hours to find/fix the underground connection that was corroded. 

Bottom line, I don't believe PoCo when they say everything is fine.


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## MDShunk

Dennis Alwon said:


> yeah but that's very different from a ground rod. I can see municipal water doing the job but not a rod.


Yup. Could depend a lot on soils type, proximity of the houses, and the connected load, though. I saw a gas station run half-decent with only rods for the "neutral". Symptom was that the pumps were running too slow, and the patrons were complaining. No real heavy loads other than the pumps themselves.


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## hardworkingstiff

MDShunk said:


> Yup. Could depend a lot on soils type, proximity of the houses, and the connected load, though. I saw a gas station run half-decent with only rods for the "neutral". Symptom was that the pumps were running too slow, and the patrons were complaining. No real heavy loads other than the pumps themselves.


Must have been suction pumps on a 120V circuit. Submerged pumps in the tanks run on 208V-230V.


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## Dennis Alwon

Even in good soil how could a rod make the connection from earth to the transformer earth-- now if a neutral was loose I could see it not getting enough current but actual make a pump run with a rod and nothing else has me very skeptical. That would be highly unlikely scenario but given the right conditions etc-- perhaps so.

I bet that rod was touching the water line.....:laughing:


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## hardworkingstiff

Dennis Alwon said:


> Even in good soil how could a rod make the connection from earth to the transformer earth-- now if a neutral was loose I could see it not getting enough current but actual make a pump run with a rod and nothing else has me very skeptical. That would be highly unlikely scenario but given the right conditions etc-- perhaps so.
> 
> I bet that rod was touching the water line.....:laughing:


What if you had a high water table like on the coast? I mean really high so the ground rod was well into it.


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## guest

Soil that is wet enough or high in mineral content is easily conductive enough to allow enough current to flow..remember we're talking about covering up a marginal neutral connection. And I have seen firsthand where the rods alone provided just enough of a path to cover for a missing neutral. 

FES said his problem went away when he added a second ground rod...which makes me very suspicious.


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