Pid controller?
- Thread starter muzzle flash
- Start date
I would guess it would depend where and how it was installed. Only have installed a PID in my smoker. If after the thermostat, you could crank the thermostat and use the PID to control. If before the thermostat you would want to crank the thermostat as well otherwise the thermostat will mess with your control. Or you just bypass the thermostat and you wouldn't have any issues. Setting a max temperature with the thermostat may be a good secondary control in case your PID fails.
+1 on building a separate box where your pot can plug in and turn the pot thermostat all the way up, that's how you bypass the pot thermostat.
That way you can use it for different situations, like a toaster oven, ingot making etc.
That way you can use it for different situations, like a toaster oven, ingot making etc.
Also a build where you can unplug your wires is a great idea. You can leave the thermocouple in your pot and use your PID elsewhere.
Works awesome for a smoker as well! I built mine in a pelican box. Got the inkbird set off amazon which comes with the relay and heat sink. I wired one switch to power the box, one dual outlet plug with switch for constant power and one dual outlet plug with switch to power what the the PID is going to control.
Kits from Amazon are not bad and let you get get the PID and SSD at once, probe however is rarely good for anything - get the long one separately (or 2, or 3 
).
I wouldn't go with SSR (Solid State Relay) rated for less than 40A (this is typically hugely over-rated, you're lucky if it's 20A in reality), like SSR-40DA. Disregard the brand, it's not Fotek regardless of what it says.
If you make the box out of aluminum alloy, mount the SSR in the middle of the back wall, preferably using some thermal paste (computer parts store), otherwise get the radiator.
Currently, I prefer ordering this stuff from Amazon vs China directly due to unpredictable situation with production and shipping from Mainland. HK is probably OK for now.
I like the idea that if you crank thermostat on the pot to the MAX and let the PID do the work, the thermostat still acts like a safety switch if your SSR is cooked and stays ON forever.
s>
).I wouldn't go with SSR (Solid State Relay) rated for less than 40A (this is typically hugely over-rated, you're lucky if it's 20A in reality), like SSR-40DA. Disregard the brand, it's not Fotek regardless of what it says.
If you make the box out of aluminum alloy, mount the SSR in the middle of the back wall, preferably using some thermal paste (computer parts store), otherwise get the radiator.
Currently, I prefer ordering this stuff from Amazon vs China directly due to unpredictable situation with production and shipping from Mainland. HK is probably OK for now.
I like the idea that if you crank thermostat on the pot to the MAX and let the PID do the work, the thermostat still acts like a safety switch if your SSR is cooked and stays ON forever.
s>
Kits from Amazon are not bad and let you get get the PID and SSD at once, probe however is rarely good for anything - get the long one separately (or 2, or 3
I wouldn't go with SSR (Solid State Relay) rated for less than 40A (this is typically hugely over-rated, you're lucky if it's 20A in reality), like SSR-40DA. Disregard the brand, it's not Fotek regardless of what it says.
If you make the box out of aluminum alloy, mount the SSR in the middle of the back wall, preferably using some thermal paste (computer parts store), otherwise get the radiator.
Currently, I prefer ordering this stuff from Amazon vs China directly due to unpredictable situation with production and shipping from Mainland. HK is probably OK for now.
I like the idea that if you crank thermostat on the pot to the MAX and let the PID do the work, the thermostat still acts like a safety switch if your SSR is cooked and stays ON forever.
s>
I bought thermocouples from china where at least one will fail per order, always buy 3 minimum. As for heat sink even old CPU heat sinks work well and are usually in peoples scrap piles.
Picture below also shows a circuit breaker, always a good idea to have a fuse/breaker for your project
vagrantviking
CGN Ultra frequent flyer
- Location
- High River, Alberta
Kits from Amazon are not bad and let you get get the PID and SSD at once, probe however is rarely good for anything - get the long one separately (or 2, or 3
I wouldn't go with SSR (Solid State Relay) rated for less than 40A (this is typically hugely over-rated, you're lucky if it's 20A in reality), like SSR-40DA. Disregard the brand, it's not Fotek regardless of what it says.
If you make the box out of aluminum alloy, mount the SSR in the middle of the back wall, preferably using some thermal paste (computer parts store), otherwise get the radiator.
Currently, I prefer ordering this stuff from Amazon vs China directly due to unpredictable situation with production and shipping from Mainland. HK is probably OK for now.
I like the idea that if you crank thermostat on the pot to the MAX and let the PID do the work, the thermostat still acts like a safety switch if your SSR is cooked and stays ON forever.
s>
I'll second the 40amp SSR. Just had a 25amp one die in the PID I've been using. Lasted a couple years but I wouldn't say it was used a great deal. When it failed the output still read 125 V but there wasn't enough amperage to run an LED light bulb so nothing dangerous was happening.
When I run the lead pot or toaster oven on it I just crank the control to max and the PID cycles it. I'm intending to go into the toaster and rewire the convection fan to it's own power supply someday. In the meantime I leave that off.
The newer ones I made have a coupler so different thermocouple probes can be used and a power switch but you can get as complex or as simple as you like. There's lots of advice on casting forums, home brewing sites and many other places online.
I have several pots (RCBS, LEE and Saeco) for different alloys and have a suspicion that Self-Learning /Auto-tuning mode on the PID is confused every time I switch to different pot, probably due to variability in capacity, power and heat inertia. Going to build a dedicated controller for each pot and oven if/when my pre-pandemic orders thru Fleabay come from China . After proper bleaching and UV-treatment of packages, of course!
As for SSRs, I'll probably continue my practice of padding Amazon orders to the desired $35 free shipping threshold by ordering an extra 40 or 60 DA SSR.
s>
. After proper bleaching and UV-treatment of packages, of course! As for SSRs, I'll probably continue my practice of padding Amazon orders to the desired $35 free shipping threshold by ordering an extra 40 or 60 DA SSR.
s>
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I have several pots (RCBS, LEE and Saeco) for different alloys and have a suspicion that Self-Learning /Auto-tuning mode on the PID is confused every time I switch to different pot, probably due to variability in capacity, power and heat inertia. Going to build a dedicated controller for each pot and oven if/when my pre-pandemic orders thru Fleabay come from China
As for SSRs, I'll probably continue my practice of padding Amazon orders to the desired $35 free shipping threshold by ordering an extra 40 or 60 DA SSR.
s>
Most, if not all, PID controllers you have to turn on the auto tune function. then when tuning is done you turn it off
vagrantviking
CGN Ultra frequent flyer
- Location
- High River, Alberta
It does seem to do better if you leave it on one device but even the changing levels in the pot will keep it from tuning as well as it might. Tuned or not a PID is a huge improvement over guessing and easier than chasing temperatures with just a thermometer. I'd hate to go back to life without.
https://www.amazon.ca/gp/product/B00FVRJ9PE/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
Any PID thats says [FONT="]REX-C100 [/FONT]https://www.amazon.ca/gp/product/B00LHKXZAO/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
SSR...take you pick.
Thermocouples are really cheap(compared to buying in Canada) so order two or three
Any PID thats says [FONT="]REX-C100 [/FONT]https://www.amazon.ca/gp/product/B00LHKXZAO/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
SSR...take you pick.
Thermocouples are really cheap(compared to buying in Canada) so order two or three
That's my motto too!
There is very little consistency on the lower end of PIDs as far as brand names, every time I go shopping it's a different name! It's mass production, so as long as the unit has an SSR output, it should be OK for non-critical application like heating lead.
Same with SSRs, you only need "honest" 6-8A to feed the pot, but assume at least 3x (5 is better) coefficient for Ebay/Amazon SSRs. Here is why...
OTOH, thermocouples are fairly good for the price, there is nothing inside that can be replaced with cheaper stuff.
s>
vagrantviking
CGN Ultra frequent flyer
- Location
- High River, Alberta
I had one PID that was no good out of the box but of course it had been on a shelf for a year before I'd tried it. Was a no name cheapest available sort of deal. Replaced it with an Inkbird which seems like a brand that has a little consistency and reputation though I haven't used it much yet.
