ECN Forum Forums General Topics of the Trade General Discussion Area Electrical Fire

Many years ago the fire Dept. had a house set for demolition and asked us to set electrical fires.
Used multiple two wire extension cords with cracked insulation and heat lamps for a load. No Fire.
Tied the blade of a window fan and energized it. No fire.
Tried the movie trick of a light bulb with gasoline in it. It lit until the filement failed. No fire.
Put a light bulb next to some paper and before I finished telling the fire chief that it would probably take a while the paper and the wall were fully enveloped.

Alan--
The biggest problem is having a safe / controlable power source with enough power to get things started.

Get a bunch of 'recycled' household appliances. (Computers, perifiral power supplies, alarm clocks, low voltage lights, electric blankets, toasters, coffee makers, etc.) Load them at varying degrees on a few 14/3 circuits on a panel, then cut the neutral out of the panel.

Or, set-up a short circuit on a long run through the house with no OCP, or a known faulty OCP.

We used to do a simulation for the HS kids. 2 gang plastic box. Drill a hole in each side (L & R) & put a screw thru each hole with a nut on the inside. Connect 120 hot to one side and 120 neut to the other. Stuff the box loosly with steel wool then tissue. The steel wool will spark/burn and set the tissue on fire. Sometimes it takes a few minutes so we'd set it off to the side to see if anybody noticed the smoke before it went up in flames.
A word to the wise (which I wasn't the first time) ... don't put it under the smoke detector. Principal sure was mad.

Here is a gross overload event I remembered from High School. We had wired up some stage scenery with 70 40W bulbs using 18 AWG zip cord, and the plug was at the end of the string. The first time we powered it up, the insulation melted right off the plug wires.

Plug in some space heaters to a cheesy zip cord extension cord and see what happens.

If you can borrow an IR thermometer, plug in a heavy load to a worn receptacle and measure how hot the plug gets.

Steve that sounds like a safety hazard for a school setting. Then again so would mine. (In a school setting)

I like the idea of the soldering gun, and the romex, w/ a good spiel and lots of pictures, could be a good demonstration.

Lint build-up in a desktop computer.

Table lamp turned over, still on and resting against curtains.

Actually, neither of these are electrical fires, but if the electrical power were off, the fire would not have started.