1. #1
    Junior Member

    Join Date
    Jul 2001

    Default 3-way lamp and bulb

    I've been asked to review a fire scenario involving a 3-way lamp and 3-way bulb. The homeowner states that the bulb was not working in at least one and maybe two of the three positions, 50w, 100w, or 150w. If the switch was turned enough times, the bulb would light the owner states. The theory is that the switch was in one of the on positions but the bulb was not lit because the filament for that particular wattage level was broken and not connected. If this lamp was knocked over onto the bed, could this bump or movement reconnect the filament and complete the circuit to illuminate the bulb, resulting in an ignition of the lampshade and then other combustibles?

  2. #2

    Join Date
    Jan 2001
    South Central, PA, USA


    I think the cause is contained in the property owners statement,

    "If the switch was turned on enough times, the bulb would turn on."

    This indictaes to me that the switch was worn out, defective and the fall could have bumped it enough to comlpete the circuit.

    I take it the bulb was in direct contact with bedding, seat cushion, etc and this then ignited those materials.

    Sounds like the cause to me.
    These views/ opinions are my own and not those of my employer/ department.

  3. #3
    Forum Member

    Join Date
    Dec 2000
    F.L. CO,USA


    I have seen exactly what you describe. A burned out buld can be powered on and shaken to attain connect at the filament. This would be real true in the case of three way because of the filament length and configuration. I dont believe the switch is at fault.

  4. #4
    Junior Member

    Join Date
    Oct 1999
    Freedom Fire Dept / Kaukauna,Wi,USA


    With having 4 positions on the switch(3-on, 1-off) and 2 of the "on" positions not working, what are the chances that the owners were turning the switch to the "off" position every time they wanted to turn the light off?(not likely) It's very possible that the switch was in the on position without the user knowing it and when tipped over the filament reconnected lighting the bulb and igniting any combustible in contact with the bulb.
    Lt. Timothy J. Helms
    Freedom Fire Dept.
    Freedom, Wi.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Log in

Click here to log in or register