Recently my electric clothing dryer stopped working. Blew the thermal fuse. replaced. Later the heat still wasn't working and I found a lack of continuity on a couple of terminals on the timer, the heating element circuit could not be closed. There is just too much corrosion even after cleaning to get a good connection inside the timer.
Thing is this is a very basic mechanical timer/switch that costs 75$. I feel like for the same price I could run this with an ardunio instead. More fun and way cooler.
So now on to my problem. I cant seem to find a relay suitable for the load generated by the dryer. I need a relay that can handle 240 volts and from what I can see would need to handle about 4k watts? Amazon, adafruit, nothing as far as I can find. I am wondering if someone with more electrical experience can suggest an appropriate relay to use.
PS Notes: Looking a bit harder I found this under furnace parts on amazon. https://www.amazon.com/dp/B019132A1I?psc=1
Thanks all for your input. I suspected the reasoning behind a very simple (now I know what to call it) centrifugal switch. The heater cannot physically be a completed circuit without engaging the blower. I realize this now looking at the order of the copper bars. I don't know that is really intentional as a "safety" feature, but fair enough, you're right I don't know for sure.
I've decided to NOT do this project simply considering the risk/reward as someone pointed out. I strongly believe the risk truly isn't that great, and ill explain my reasoning below, but in any case, not a great first Arduino project. Maybe in the future if I have a spare dryer and more time to work out the safety aspects. I'm pretty sure we could, with time, make an even safer dryer that the manufacturer.
So here is why I think the danger of this is pretty exaggerated.
I still strongly believe that in the event the blower does not engage the thermostat and or thermal fuse would blow very quickly, stopping heat production.
Lets say for whatever reason the element does get stuck on. Not ideal right? but is it truly going to start a fire? I am certain lint in the exhaust is infinitely more dangerous, and ONLY when the blower is running.
The heating element itself is well sealed away from anything flammable, it is completely encased in a few layers of metal, the floor is cement and the basement wall is cement. Consider that only fresh air is pulled into the element. It is NOT full of flammable lint, the lint is no where near the element. Only when the blower is on can the heat reach anything in the exhaust section.
Having said that there are a few factors here. 1. my wife wants the dryer fixed sooner than later :O and 2. I can't deny that SOME risk at least potentially exists. 3. I'm a coder with limited electrical experience. My first project should likely not involve 240v or 4k watts :P Never the less that's to you guys I did learn a few things anyway.