I'm building a reflow oven. I know what I'm doing, I just want to verify my plans to make sure I'm not doing anything stupid before I start.
The idea is to have an arduino (powered externally) control a relay which is spliced into the neutral wire of an AC cable connected to a toaster. I chose to splice the neutral cable and not the live wire for obvious reasons (that way if you touch something exposed by accident, you're less likely to be shocked). Meanwhile I plan on putting all of the splicing under several layers of heatshrink, glue gun, and electrical tape, and then inside of a small plastic project box for extra protection.
I'm just mainly wondering if the insulation I'm using is safe enough.
Also, should the thermocouple be touching the metal grill that the pcb board to be soldered sits on? should it be in the air above the pcb board? I imagine the safest bet is to take a small pcb board that's not being soldered and attach the thermocouple to that one and then place it next to the pcb board being soldered (in order to best simulate the temperature on the actual cooking pcb board).
thanks for your help!
After getting several answers, I realized I made a huge mistake in trying the neutral wire. Thanks guys. I don't know what I was thinking. (I was so concerned about the insulation failing on the connection to the relay that I forgot that the heating elements weren't particularly isolated).
Also, I will definitely go with with a double-pole relay (well, I'll just get a second single-pole relay and connect their inputs together).