I have a problem that has happened twice now.A 150w lamp in a fixture has shattered leaving only the lamp shell in the socket.First time pulled the fixture down and found a loose connection, assumed this was creating heat and i had found the problem.Guess not! Any one here have any ideas. Thanks I need to get to the bottom of this because it is in a church 15 feet above the main section of pews, and luckily it has done it when no one was sitting there.
incandesant lamp "blowing up"
- Thread starter lucky1974
- Start date
- Status
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: incandesant lamp "blowing up"
Is this the correct lamp for the fixture?
Is this the correct lamp for the fixture?
ramdiesel3500
Senior Member
- Location
- Bloomington IN
Re: incandesant lamp "blowing up"
Might check for a roof leak. One drop of cold water hitting that lamp at speed can pop it to pieces!
Might check for a roof leak. One drop of cold water hitting that lamp at speed can pop it to pieces!
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: incandesant lamp "blowing up"
Did it happen just as the lights were being turned on, or at a random time while the lights were already on? Where was the loose wire (i.e., in the fixture, in the pendant, or in a junction box somewhere)? How many lights and what other loads are on the same circuit? Most importantly, is this a multi-wire circuit (i.e., with a common neutral)?
Did it happen just as the lights were being turned on, or at a random time while the lights were already on? Where was the loose wire (i.e., in the fixture, in the pendant, or in a junction box somewhere)? How many lights and what other loads are on the same circuit? Most importantly, is this a multi-wire circuit (i.e., with a common neutral)?
Re: incandesant lamp "blowing up"
Ram, funny You bring that up worked with a guy that dipped "Skoal" and while We up on a JLG he "spit" on a 400w 277v Bulb (try'in to be funny I guess) High bay, We were changing out ballasts and Yup! You know the rest.....BLAM! Helpers. Can't work without "em" and "By Hell" can't "shoot" "em"
Ram, funny You bring that up worked with a guy that dipped "Skoal" and while We up on a JLG he "spit" on a 400w 277v Bulb (try'in to be funny I guess) High bay, We were changing out ballasts and Yup! You know the rest.....BLAM! Helpers. Can't work without "em" and "By Hell" can't "shoot" "em"
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: incandesant lamp "blowing up"
Lucky said he had found one loose connection. Perhaps there were others. I was curious as to the location of the one he found. A loose wire can cause an intermittent connection/disconnection. This can lead to arcing, which in turn can impose a higher voltage on the circuit than would normally be seen. That can be one cause of a blown bulb.
If you have a 3-wire circuit (i.e., 2 hot wires and one shared neutral), and if that neutral wire becomes disconnected, then the 240 volts of the power supply (i.e., line to line) will be shared with the loads connected to the two hot wires. The amount of voltage across any given load will be a function of the resistance of that load and the resistance of the rest of the circuit. If for example you have only one load, a 60 watt bulb, on one circuit, and only one load, a 120 watt bulb on the other circuit, and if the shared neutral is open, then you will have 160 volts dropped across the 60 watt bulb and 80 volts across the 120 watt bulb. That is likely to blow the 60 watt bulb, and not damage the 120 watt bulb.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: incandesant lamp "blowing up"
[ February 08, 2006, 04:31 PM: Message edited by: charlie b ]
No. Really, it is a "grounded conductor."
[ February 08, 2006, 04:31 PM: Message edited by: charlie b ]
ramdiesel3500
Senior Member
- Location
- Bloomington IN
Re: incandesant lamp "blowing up"
Triphase
Yep, we have had folks spray water on metal halide lamps KABOOM and many other oddities in the past. So when things like exploding lamps come up, I try to look for non-electrical possibilites first before commencing with the tools!!! Kids with these litte rubber "super balls" can cause all kinds of lamp and fixture problems too! For the glass bulb to fracture, it must see extreme stress as the result of an impact or an extreme temperature differential across its surface. This can happen when water hits the glass or maybe when the filament explodes violently as the result of over-voltage. I would not want to rule out a faulty lamp base. If the base is bent or dented, it could be flexing the lamp screw base causing the bulb to be under stress before it heats up. Will be interesting to hear what is happening with this particular case!
Triphase
Yep, we have had folks spray water on metal halide lamps KABOOM and many other oddities in the past. So when things like exploding lamps come up, I try to look for non-electrical possibilites first before commencing with the tools!!! Kids with these litte rubber "super balls" can cause all kinds of lamp and fixture problems too! For the glass bulb to fracture, it must see extreme stress as the result of an impact or an extreme temperature differential across its surface. This can happen when water hits the glass or maybe when the filament explodes violently as the result of over-voltage. I would not want to rule out a faulty lamp base. If the base is bent or dented, it could be flexing the lamp screw base causing the bulb to be under stress before it heats up. Will be interesting to hear what is happening with this particular case!
frenchelectrican
Senior Member
- Location
- Nord'est Wisconsin et Paris France
Re: incandesant lamp "blowing up"
the other thing is the viberations it can make the light bulb exploded too.
Triphase just try my shop every time i fired up my diesel truck cold from time to time i do actally heard MH bulbs do exploaded from very cold diesel exhaust KaBooom zeetttpoppp that the sound of big HID bulbs go out after that i got wise with it i put hevey duty lens below the bulbs to prevent blowing up again .
back to the point here about light bulbs exploading some time the indscent bulbs can expolde by power surge as well i ran into few of that the last one did wonderfull damge was 1000 watt 277 volt bulb [ i am not kidding on this size ] and what i did is add inline fuse so when the bulb ready to explode the fuse blow just right on time
but the other possiblty what other person saying the socket is offline not on right postion it can do put alot of stress on base and can crack the same way.
there is other possibty but sound far fetched some case very cold air getting to the hot bulbs can do funny way too [ just a thought ]
Merci, Marc
the other thing is the viberations it can make the light bulb exploded too.
Triphase just try my shop every time i fired up my diesel truck cold from time to time i do actally heard MH bulbs do exploaded from very cold diesel exhaust KaBooom zeetttpoppp that the sound of big HID bulbs go out after that i got wise with it i put hevey duty lens below the bulbs to prevent blowing up again .
back to the point here about light bulbs exploading some time the indscent bulbs can expolde by power surge as well i ran into few of that the last one did wonderfull damge was 1000 watt 277 volt bulb [ i am not kidding on this size ] and what i did is add inline fuse so when the bulb ready to explode the fuse blow just right on time
but the other possiblty what other person saying the socket is offline not on right postion it can do put alot of stress on base and can crack the same way.
there is other possibty but sound far fetched some case very cold air getting to the hot bulbs can do funny way too [ just a thought ]
Merci, Marc
allenwayne
Senior Member
Re: incandesant lamp "blowing up"
We had a rash of 60 w clear bulbs that our purchasing agent thought were a great buy falling apart when 1st turned on.The entire glass bulb would seperste from the base.Solution was a dumpster and a material request form for 500 more bulbs
We had a rash of 60 w clear bulbs that our purchasing agent thought were a great buy falling apart when 1st turned on.The entire glass bulb would seperste from the base.Solution was a dumpster and a material request form for 500 more bulbs
LawnGuyLandSparky
Senior Member
Re: incandesant lamp "blowing up"
They're only (exactly) 57 watts though...
Hey if you need clear bulbs, the City of NY has about a kabillion in storage since they switched to LED traffic signals.Originally posted by allenwayne:
We had a rash of 60 w clear bulbs that our purchasing agent thought were a great buy falling apart when 1st turned on.The entire glass bulb would seperste from the base.Solution was a dumpster and a material request form for 500 more bulbs
They're only (exactly) 57 watts though...
- Status