Thanks for the reply! I plugged the box into an adjustable voltage plug I have and set it at 12 volts. The box powers, lights blink, the LCD menu shows up, and the relay clicks on and off every few seconds. I can only assume it's working.
I will try as you suggest, and unplug the osPID from the ssr to see if there is any difference. With regard to the inherent physics: I have a small popcorn air popper that I am using to roast coffee. This consists of a nichrome wire element at 240V and a small electric fan. I have wired the ssr into the active wire to the nichrome element - the fan is in parallel.