recess cans

[iwire]

I agree. I cannot understand how this would happen electrically. Furthermore, a loose connection is no different than standing at the switch and turning it on and off erratically. I can't see how that would affect lamp life at all.

I believe that turning the lamp off long enough for it to stop producing any light and turning it back on over and over would shorten the life due to the thermal cycling.

I have a much harder time believing that cycling a lamp so fast that the human eye can not detect it would shorten the life as the temp would not be cycling either. (at least not much)

 

[Rewire]

They sure do, I am just not so sure a 200F - 500 F terminal will matter in the least to a filament operating at about 2500 C

Just guessing here, really looking for some facts. :smile:

I may not have facts but I do have something that is just as good and that is experience.

I have replaced the socket on recessed cans that were loose and showed signs of heating( white wire turning brown) and this has stopped the problem of short lamp life,I am just using deductive reasoning of eliminating all possibilitys and whatever is left has to be the problem. I don't know why it worked it just did.

 

[Ohmy]

AC turns off 60 times a second.:smile:




So your saying the arc causes slower fluctuations then a dimmer (which matches 60 Hz supply ............. in that case it would be very visible to the eye that the lamp was pulsing.

Still having some doubts that adding any sort of impedance to a incandescent lamp circuit will shorten it's life. :smile:

Yeah, I am deffinately talking about situations where the light is flickering (on/off) to the naked eye.

I agree with you the no change in appreciable change in temp. means no change in the apprecaite of the light.

Like a connection that works for a minute...gets hot sparks for a second than stops working for ten minutes then contracts and starts work again...etc., etc.

 

[ohm]

recess cans blowing bulbs(2 every 2 weeks)---anyone every had problem like this?only happening with 6 lights-4inch direct contact

Were the bulbs that were taken out tested?
Could be bad sockets or connections temporarily made contact after a new bulb was installed.

As rewire said bad connections don't burn out bulbs, unless an arching socket melts the soldered connections on the bulb.

I always use 130V bulbs on hard to replace bulbs, even if the line voltage is only 120V. Using this example, a 1000 hour bulb last 2853 hours if just run at a reduced voltage. Lumen output would however drop from 1750 to 1335.

 

[mjf]

poor quality lamps

poor quality lamps

The Phillips BR 30 indoor floodlight contractor packs that home cheapo sells are horrible. I've had numerous calls from customers over the last few years concerning lamps in 6" cans burning out quickly and frequently. Every and I mean EVERY single instance of this occurring the HO had purchased and installed the aforementioned lamps. I installed 130v lamps each time and haven't had a repeat problem once.

 

[iwire]

I may not have facts but I do have something that is just as good and that is experience.

Just as good? No, not really, no more than an eye witness is 'just as good' as a video from a surveillance camera.

Going by just our own experience leads to misconceptions and myths.

I don't know why it worked it just did.

Exactly, so we do not know if it was something besides the socket.

 

[Power Tech]

POCO only guarantees 10% fluctuation. Unless it's PG&E:grin: Then the unlimited voltage / unlimited amperage rule applies.

 

[Power Tech]

I agree Home Despot does sell 2nd's. Tools / plumbing / electrical -- be careful. Too much pressure on the manufacturers. The last time I went in I saw a 2" rigid no thread, $40. Is that real?

 

[Rewire]

Just as good? No, not really, no more than an eye witness is 'just as good' as a video from a surveillance camera.

Video can be altered rather easily, facts are derived from expierience

Going by just our own experience leads to misconceptions and myths.

maybe its not a double blind study but experience should not be so easily brushed aside

Exactly, so we do not know if it was something besides the socket.

It could have been little green pixies but cause and effect would lead to the logical conclusion that an action taken that produces a result that can be duplicated by the same action would be the correct course of action,it is not nessesary to know why it works for it to work.

 

[macmikeman]

Several times I have repaired strings of recessed cans in various houses where the original installing electrician (or somebody) removed the red plastic paint guard plugs from the sockets, and the painters and ceiling texture sprayers shot the socket with just enough goop to allow the lamp to work, yet there is problems. Makes for a boring but lucrative service call to scrub out the dried paint from inside the socket. That can cause the same problems of short life to bulbs.

 

[ike5547]

I may not have facts but I do have something that is just as good and that is experience.

I have replaced the socket on recessed cans that were loose and showed signs of heating( white wire turning brown) and this has stopped the problem of short lamp life,I am just using deductive reasoning of eliminating all possibilitys and whatever is left has to be the problem. I don't know why it worked it just did.

I've discovered that the majority of the time incandescent short lamp life claims aren't true. I never say it outright to customers and I always presume that they are correct and act accordingly, i.e., search for little problems in the fixture and repair them etc.

Usually there is at least one identical fixture next to the one in question or there are multiple lamps in the same fixture. Human memory being what it is, it's easy to lose track of which bulb you put in what fixture and when.

If lamps are really going out fast it is probably a problem with the lamps (bad batch, manufacturer, etc.)

If I don't find anything, as often happens, I replace the lamp with a new one and mark the date on it. Next time it blows the customer can see how old it was.

That's my experience anyway.

 

[Ohmy]

I've discovered that the majority of the time incandescent short lamp life claims aren't true. I never say it outright to customers and I always presume that they are correct and act accordingly, i.e., search for little problems in the fixture and repair them etc.

Usually there is at least one identical fixture next to the one in question or there are multiple lamps in the same fixture. Human memory being what it is, it's easy to lose track of which bulb you put in what fixture and when.

If lamps are really going out fast it is probably a problem with the lamps (bad batch, manufacturer, etc.)

If I don't find anything, as often happens, I replace the lamp with a new one and mark the date on it. Next time it blows the customer can see how old it was.

That's my experience anyway.

There is alot of true to this! Think about it...the bulbs that keep blowing all the time are generall in the kitchen and hallway which generally get used the most often and they are almost always recessed lights. So you have 6 lights in a room that get used more than any in the house. Anytime one of the six lights go out the burnout is attributed to all 6 lights (these darn lights, etc.) but only the offending bulb gets replaced. If one recessed light got a new bulb every three months, that would mean the individual bulbs are lasting well over a year which is good for the most frequantly use lamps in the house. Yet, the customer will say "these lights burnout every three months." Which is true, but the bulbs are lasting over a year, its just they are on different life cycles.

This is why the 130v bulb trick is soo great. Not only do you get a better lamp but you also guarantee the lamps are new and on roughly the same life cycle. If you just replace the light over the stove, they will call you in a week and say "see it didn't work, the one over the fridge is out now."

 

[Rewire]

I've discovered that the majority of the time incandescent short lamp life claims aren't true. I never say it outright to customers and I always presume that they are correct and act accordingly, i.e., search for little problems in the fixture and repair them etc.

Usually there is at least one identical fixture next to the one in question or there are multiple lamps in the same fixture. Human memory being what it is, it's easy to lose track of which bulb you put in what fixture and when.

If lamps are really going out fast it is probably a problem with the lamps (bad batch, manufacturer, etc.)

If I don't find anything, as often happens, I replace the lamp with a new one and mark the date on it. Next time it blows the customer can see how old it was.

That's my experience anyway.

Sharpies are great tools,we always date stamp lamps and ballasts too .I remember replacing a ballast in an office that was dated 10 years ago.
We had a customer call about a lite out on his dock he said he tried another bulb and it still didn't work so we sent a service truck out the tech placed a fresh bulb off the truck into the fixture and it worked fine,the tech showed him his "test" bulb also had a burnt fillament.

 

[ohm]

POCO only guarantees 10% fluctuation. Unless it's PG&E:grin: Then the unlimited voltage / unlimited amperage rule applies.

It really bothers me that we need 4/0 AL for a 200A resi but he POCO will hook it to a #6 or #4 AL. In order to get 120/240V under a load they have to supply 130/260V without a load, due to the VD in THEIR wire.

 

[iwire]

It really bothers me that we need 4/0 AL for a 200A resi but he POCO will hook it to a #6 or #4 AL. In order to get 120/240V under a load they have to supply 130/260V without a load, due to the VD in THEIR wire.

They size the wire to the load, not to what the NEC says the load will be.:smile:

The power company knows better than anyone what the actual load of a dwelling unit it is.

 

[electricalperson]

How would lose terminals contribute to lamp failure? :-?


I have heard this before and personally have felt it is likely a myth.

it is a myth. now that i understand ohms law a little better i believe a loose connection in series will do nothing to a lamp. if anything the voltage might be lower.

only time a loose neutral will cause lamps to fail is if its on a MWBC.

 

[Rewire]

it is a myth. now that i understand ohms law a little better i believe a loose connection in series will do nothing to a lamp. if anything the voltage might be lower.

only time a loose neutral will cause lamps to fail is if its on a MWBC.

why just on a multiwire branch circuit?

 

[electricalperson]

why just on a multiwire branch circuit?

because if you remove the neutral depending on whats on the circuit you will put everything in series and its possible to have 240 volts across a lamp.

for example if you remove the neutral you could have 200 volts across one load and 40 volts across another. depends on the resistance of each object. thats why we need to pigtail our neutrals on MWBC

 

[electricalperson]

here is what i am talking about thanks to mike holt

 

[electricalperson]

it got quiet all of a sudden:grin: