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heat sensitive wall outlet Answered

Does any one have or had plans for a wall plug outlet or an extension cord from a tool that would turn off if the temperature of the devise reached a preset degree.  i.e. your coffee machine operated normally but it caused the duplex plug to overheat and the circuit would shut down avoiding a possible fire condition. 


A breaker in an outlet could limit current.

Or it could have an IR thermometer which could be aimed by the user at the appliance. This thermometer would interface with a computer which would shut off a relay when your coffee was warm. or maybe after the coffee maker bursts into flames.

or you could spend more on a good coffeemaker.

A few years ago a friend came home to ee a blackened spot on the sheet rock above a wall plug that had an " always on" television pluigged in. The internal circuit eventually shut down the T.V. but not until it had charred the wall plug and sheet rock. Thats one reason I even discussed the idea. Thanks to all.

it sounds like a defective outlet. Or corroded plug. Too much resistance in the outlet means that it acts as a fuse. A slow blow fuse. Probably not an issue with the appliance itself.

These problems usually hapen from overloading an outlet with badly corroded or worn out contacts.
Happens even more often when people plug/unplug running devices.
A very common problem down here with powerboards.
Due to greedy landlords houses usually only have a bare minimum in power outlets so people are forced to use a lot of powerboards.
I no longer buy them if they if I can't open them to inspect the contacts once a year or so.
Learned my lesson when my toast smelled like plastic and smoke came up from the powerboard behind the toaster.

Maintenance and care is all that is required to keep power outlets in a good working condition - that includes the mess of cables going into their back ;)

What you say is accurate but please ........I was only using a coffee maker as an example . I don't drink coffee and don't have a machine. Any electrical appliance that uses resistance to create heat would be a better example. Thank you for your feed back.

ok. I was getting ridiculous.

I'm inclined to think that putting the safety device in the appliance is best. If you'd like to plug a 1500 watt space heater in, or a 15 watt soldering iron, and have the outlet determine overheating (not excessive current) , well, you've got a serious engineering challenge.

It's also interesting that, as a filament grows hotter, it's resistance goes up. Thus current goes down. So, if the outlet checks current, it may miss an overheating event.

Another option might be to hook a smoke alarm to a wireless transmitter which shuts off outlets if smoke is detected.

Are we talking about heat in the devices heating element or in the circuitry / wiring? If the heating element exceeds a set temperature there will be a built-in thermal cut out on any device that is built to decent minimum standards imposed by the nation's safety regulatory body.

If we are talking about heat in the wiring / circuitry as a result of a fault, every electrical device in the U.K. is fused at the plug as well as fuses that are included in the circuitry, I'd expect this to blow before any major issues arise.

That's good advice about unplugging outlets with the device still on. I also struggle with the duplex receptacle plugs that allow you to push the wire into a gripping socket hole versus bending the wire around the screw and tightening it down. I have heard the sockets are safer and also that you should never use them. I asked an electrician and he said bending the wire around the screw is the only way to go. Problem is many do-it-yourself types are not able to tighten the screw enough for a solid contact. I presume U.L. or N.S.E.C would have tested them. Also I always buy a name brand receptacle rather than the bargain ones as I feel the name brands are better made. I would love to hear any ones thoughts on this.

What about a fuse?

The point where it would catch on fire does depend on the temperature of the room,

many devices like hair dryers have a thermal circuit breaker built in. Dunno about coffee machines. Can I take yours apart to look?

+1 usually anything that has a heating element will have a thermal cut-out for safety reasons (otherwise it catches fire!) but the quality of safety built-into devices depends on the country where they are manufactured and sold (i.e. what safety standards they must comply to). The temperature sensing would occur inside the device not at the wall socket.

Are they the ones who certify dairy products to be wholesome and hormone free?

mmmmmmm...... my typo... "uDDerwriters laborotory" Yes. that would have to do with milk safety.

(Underwriters Laboratory might be more pertinent to this thread)

You need to check the temp inside the connected device.
Unless I missed something nothing simple will work for this.

A person with some electronic building skills could easily build a temperature sensitive shut off devise. It would use a thermistor as the brain with a few ancillary components to assemble it. It would not be portable as such, rather it would require enough space to hold the components on a circuit board. As an aside to my original thoughts about this idea. I only used a coffee maker as an example since they can draw a few watts of power. I do not drink coffee or own a coffee machine. Coffee is a stimulant and not something I want in my body.

Time to get a bigger coffee maker if you are drinking so much coffee that you have a runaway machine. I think normal circuit breakers are designed to trip long before the wires get overheated. Thermal shutoff should be built into the device itself and probably part of that UL, CE or other consumer safety approvals. Sure, one could plug powerstrip into powerstrip and overload a circuit and maybe heat up the outlet or wires but hopefully you don't do that.

Yes indeed the circuit breaker should trip if there is an over load on that breaker or a fault in the machine but while many appliances do have thermal overload devices not all do, especially older units. I once grabbed a fondue pot cord to unplug it at the wall and it nearly burned my hand. Thank you for reading my idea and thank you for your input,

I could see situations where there is a danger but the manufacturers probably took a look at the statistics of accidents caused by overheated outlets and decided it was not worth their time/money/profit to build and include such a safety feature. Maybe make the plug plastic something heat reactive to visually warn the user if it is too hot.