Forum newbie but not new to electrical stuff. I have a challenge I can't answer and am hoping to get some ideas.

I have two sinks in the master bath with wall mounted three-light fixtures above each sink. Never had a problem for years. About a year ago I replaced all 6 bulbs in these fixtures. The first day within hours of installing the bulbs one of them was broken: glass on the counter. I wrote it off as a fluke. Within two or three days three more exploded leaving glass on the counter. I figure the lot of bulbs were defective and returned the remaining 8 (out of box of 12).

I bought some new bulbs elsewhere, installed them, and got similar results. Tried yet another brand of bulbs and got the same result.

Here area few facts to add to the story:

- all the bulbs I tried are 130v bulbs. I prefer these because of the long life I typically get. I had some 130v spots in the kitchen that survived 10 years of daily use.
- for some reason, the center bulb in these three-light fixtures out-lasts the other two. I've gotten 4-6 weeks out of the center bulbs while the outside bulbs last a week at the most. Not years like the kitchen but better than the outside two.
- I tried A15 fan bulbs and flame-shaped bulbs in the process.

I thought I understood 110/220 wiring but this makes no sense to me. I would appreciate any thoughts.

 

But you have modern power, 120/240. Have you measured the voltage at the light?

 

Contact the bulb manufacturer or importer. You may be correct in thinking a batch of bad bulbs were sold. that batch could entail thousands of bulbs.

 

He tried different bulbs. Unlikely they were all from a bad production run. I think he's got an electrical problem. Send pics of you fixtures.

 

Are these incandescent bulbs? Did you actually see one explode? Do they seem unusually bright and bluish compared with other incandescent bulbs?

 

They are incandescent A15 and flame bulbs. Haven't seen them explode but glass on the counter means they either exploded or imploded. Tried three different brands with the same results.

Actually, due to supply problems, 110/220 is probably more accurate than 120/240. I have 750 feet of 1/0 aluminum coming from a 100 amp service panel to supply the house. I probably lose 10V in line loss. Running the oven dims the lights a tad.

Since I run 130V bulbs they should handle a large spike - right? Especially on top of a nominal 110V supply. Low voltage wouldn't cause exploding bulbs would it?

It is only this one room anyway. Rest of the house is fine.

 

Try this experiment. Get a lamp, and using one of those bulbs plug it into the same circuit as the exploding bulbs. Use an adapter if necessary. If the bulb explodes then you have an electrical problem in the fixture. Also any chance that moisture or water might be getting splashed on the hot glass?

 

First thing to do is check voltage at the socket.

 

I like the idea of trying another fixture. I've got a clamp-on fixture that will fit the bill. I will check the voltage too but don't expect an issue there cause the lights haven't been noticeably different.

I will update when I learn more.

 

"Also any chance that moisture or water might be getting splashed on the hot glass? "

Condensation on the ceiling above?

Are the lights left on when no one is in the bathroom? Jjust after someone takes a shower is the good time for water to drip and when no one would see the bulb shatter..