I am planning to use an older toaster oven to make a DIY reflow oven. Specifically the oven is a Hamilton Beach Model 31507R which is 120v @ 60 Hz and is 1300W. First things first I never trust a product label. I pulled the cover off to gain access to the heating elements, to confirm the resistance values of the four heating elements. They are wired in series so Rt= R1 + R2 ..... for a total of 44.4 Ohms (11.1 each). Now using my known Voltage of 120V and the stated Wattage on the label I can say that:
R=V^2/W - plug it in and you get 120^2/1300 = 11.076 Ohms<-- That is about what I measured on one element BUT there are 4 wired in series.
I=P/V - that yields 1300/120 = 10.8333... Amps <-- I hope this is incorrect and that little oven does not pull almost 11 Amps.
If I use numbers I measured then I get the following result:
W=V^2/R - with my values is 120^2/44.4 = 324.324... Watts <-- This is with the known 120V and the measured total resistance of 44.4 Ohms.
I=P/V - gives a much different value of 324.324/44.4 = 2.702 Amps more what I would have guessed for a tiny toaster oven.
I must be missing something elemental here series resistors should be totaled before Ohms law is applied correct? That statement assumes you are looking at the entire circuit not a single node. Wiki states "The total resistance of resistors in series is equal to the sum of their individual resistances." I know there is a problem with my math. If anyone would be willing to check / correct me I would really appreciate it. I know I can simply test the amperage of the device with my meter however I have a 10 amp fuse, so if Hamilton Beach is telling the truth about the Wattage I will smoke my fuse. One last thing that just occurred to me, is that this is AC and I should have used Z for impedance not R for Ohms but this is a purely resistive AC circuit and the equations are well, equal...... for that condition. Really if anyone out there is willing to flog me for my error I would be grateful I have spent half my day trying to decide how many magic pixies are in that wire.
I do have pictures of the oven wiring but they are freaking huge 1.2+Megs and I didnt want to kill anyone's mobile data. I need the calculated amperage to connect the correct tool for an actual amperage measurement. I can borrow a clamp meter if I have to. Once I have the numbers in place I can decide on going with a TRIAC or being shoved into using an SSR.
Again Thank you all for any help you can give.