Toaster safety- Anyone?

  • Thread starter Thread starter ExigeEvan
  • 6 comments
  • 737 views
ExigeEvan

ExigeEvan

Premium
Messages
17,192
Last Monday my cousin was still a bit hammered after the rugby (Wales lost to Ireland) and woke up abit late and rushed his breakfast. In doing so he forgot about the toast he'd put in the toaster which shouldn't have been a problem except....


The toast was abit thick, and didn't pop out. Leaving it to burn in the toaster. But the toaster never stopped and eventually turned itself into a molten mess on the counter. Causing damage to the surrounding kitchen units and leaving a slick of thermosetting plastic throughout the entire house.


Now from my DT studies my immediate reaction was WTF? How does a toaster melt itself. Surely there would be some safety device. Hell even the fuse should have blown when the heat rose and the resistance increased and this should have happened fairly early I imagine.

Now I asked my DT lecturer who's worked in industry for quite a while and he said yes, something should have been in place despite it being a £5 budget toaster. So I did a BSi check but can't get the sites from college to work at home.


So I ask you, shouldn't the toaster have switched off long before the plastic started melting?
 
Well, if the too thick toast keeps the mechanism down, and therefor the toaster running, I don't see how it should cut itself from power. There's no electronics monitoring the duration of toasting, it's just mechanics. And the fuse didn't blow because it only does when the electric components demand too much current, like when there's a short circuit. As this is not the case when toasting, even when burning the toast and melting the device itself, it won't stop.

Regards
the Interceptor
 
Hair dryers have a thermal fuse that opens with too much tempurature, which could happen with a clogged inlet and not enough airflow. I would think something similar would be in a toaster. I can see the mechanism getting jammed and not releasing, but there should be some second-level device.
By the way, toasters are not timed, they are thermostatically released. That's way continuous use, i.e. toasting a whole loaf 2 slices after 2 slices after 2, may give less and less satisfactory results.
In your actual question, a regular fuse responds to current, not temperature, and the current draw doesn't get higher and higher just because the toaster's warm. The thermal fuse, like a hair dryer, does break with heat, though.
 
ExigeExcel
But surely a thermistor, a simple and pretty cheap (even for a cheap toaster) device would do it?
Click to expand...
Theoretically yes, but how do you want to make it decide between "normal toasting mode" and "melting mode"? And the manufacturers of cheap toasters will save every money they can save, so why spend an amount of money for a case that will most likely never happen? For you, getting and building in a thermistor is no problem, but calculating the additional hardware and manpower at production, it can be too much for a manufacturer.

Regards
the Interceptor
 
wfooshee
Hair dryers have a thermal fuse that opens with too much tempurature, which could happen with a clogged inlet and not enough airflow. I would think something similar would be in a toaster. I can see the mechanism getting jammed and not releasing, but there should be some second-level device.
By the way, toasters are not timed, they are thermostatically released. That's way continuous use, i.e. toasting a whole loaf 2 slices after 2 slices after 2, may give less and less satisfactory results.
In your actual question, a regular fuse responds to current, not temperature, and the current draw doesn't get higher and higher just because the toaster's warm. The thermal fuse, like a hair dryer, does break with heat, though.
Click to expand...
I understand a regular fuse responds to current, and not temperature. That was never an issue.

My point was, and this is when I should really look at my physics notes, is that as the temperature increased the temperature of the components would. This rise would increase the resistance. But thinking about it now that means the current would be reduced. Not affecting the mains fuse.
 
I just looked at the U.L. site, and found that to be U.L. listed, a toaster must run contiuously for 7 hours!
 

Latest Posts

Back