PID wire gauge for toaster oven? Thermocouple location?

[psychbiker]

I’m building another PID for another casting pot BUT also want to use it for a toaster oven.

I got a 14ga extension cord to wire the entire PID. Should I be using 12ga instead? I don’t know the amp draw of my toaster oven. I’m checking my dad’s retired cord section, he said he thinks he’s got a lot of 12ga.

It does have a convection function I don’t think I can turn off when using. Read that I might have to wire the fan cuz it won’t work plugged into a pid. No clue bout that.

I also don’t know where to put the thermocouple in the oven. Can I just lay it in there and close the door?

[lightman]

Look at the name plate on your oven. It gives voltage and load info. Maybe in amps or maybe watts. Personally I would use #12 wire for the load carrying parts. You control wiring could be smaller. 14 ga or even smaller will probably carry the load but 12 ga is not much more expensive and is still small enough to be easy to work. I would wire the load carrying part of the insides with #12 stranded THHN or THWN. If the big box stores don't sell it by the foot stop by any electrical contractor and beg a piece of scrap in black, white and green.

[onelight]

Most of the GFI kitchen outlets around here are 15 amp so I would think most toaster ovens would be less than that I would think 14 should be fine and 12 better. Mine pid is wired with 12 but I still find myself checking the cord after a running my pot for a while to see if it is warm .

[jsizemore]

I have a 6" probe on my thermocouple. I drilled a hole through the side just below the top shelf and just poked it through. The PID cycles power to the heating element and you want the fan to run continuously. I just hooked up a separate cord to the fan and plug it in the outlet beside the PID's plug. 14 gauge will work. Divide the wattage of the unit by the voltage. Like 800 watts divided by 120 volts equals 6.6666... amps. 14 gauge wire will handle 15 amps and 12 will handle 20. You only want to run it at 80% of it's rated capacity. So 14 gauge would handle 12 amps and 12 gauge handles 16 amps.

[HATCH]

standard wall outlets are 15 amps (120v US standards)

TC placement will depend on the type of oven it is and the placement of the heating elements in that oven.

[psychbiker]

Thanks guys. Think I use the 12ga. Found a 12ga extension cord on Cl for $10. I’ll be able to use the ends too.

As far as wiring the thermocouple and fan...

Is this a permanent placement of the thermocouple? Meaning once the hole is drilled and TC probe added, that’s it? I imagine some sealing around the threads so hot air doesn’t escape? I was thinking about using the same thermocouple for both my pot and oven, swapping them when not using the other.

If the oven has convection and it’s suggested to wire to the fan to power. That means opening the toaster oven and fiddling with the wiring of the fan? If that’s the case that’s more than I want to do unless it’s kind of easy. I may try some bullets with the oven plugged into the pid and no fan and check the results.

[lightman]

Most of the GFI kitchen outlets around here are 15 amp so I would think most toaster ovens would be less than that I would think 14 should be fine and 12 better. Mine pid is wired with 12 but I still find myself checking the cord after a running my pot for a while to see if it is warm .

Just an FYI! You have to remember that a GFCI has no overcurrent protection. It monitors the difference between the neutral and hot wire. The rating is what the contacts in the device will carry.

[jsizemore]

Thanks guys. Think I use the 12ga. Found a 12ga extension cord on Cl for $10. I’ll be able to use the ends too.

As far as wiring the thermocouple and fan...

Is this a permanent placement of the thermocouple? Meaning once the hole is drilled and TC probe added, that’s it? I imagine some sealing around the threads so hot air doesn’t escape? I was thinking about using the same thermocouple for both my pot and oven, swapping them when not using the other.

If the oven has convection and it’s suggested to wire to the fan to power. That means opening the toaster oven and fiddling with the wiring of the fan? If that’s the case that’s more than I want to do unless it’s kind of easy. I may try some bullets with the oven plugged into the pid and no fan and check the results.

I measured my thermocouple with my reloading dial calipers and got a drill bit just larger than the thermocouple diameter. Drilled from the inside out to get the location and angle right. Slip the probe in from the outside and no need for sealant.

If you don't feel safe playing with electricity/magic, don't do it. Man's got to know his limitations. Most folks like the fan running full time to even the temp in the oven.

[jsizemore]

Most of the GFI kitchen outlets around here are 15 amp so I would think most toaster ovens would be less than that I would think 14 should be fine and 12 better. Mine pid is wired with 12 but I still find myself checking the cord after a running my pot for a while to see if it is warm .

That's a smart thing to do. Not all wire insulation is meant to handle heating elements! That's why the wire uses a glass insulation, high temp solderless connectors with silicone insulators, and ceramic wire nuts.