Ebay has a ton of cheap PIDs available for around $20 with thermocouple (model REX-C100 when that link dies). I'm wondering if I could use this to run a chest freezer as a fridge. I know when doing this you skip the SSR and just tie the freezer into the PID output. The specs say it's rated at 3a 250V. My question is if a small to mid size chest freezer running at 120V will be too much of a load?
Cheap ebay PID as freezer temp control
- Thread starter mrbippers
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The only thing that I do NOT like about that sale ad is that they really do not tell you a single thing about the pid. (Who makes it? The root specifications about it? A link to the data sheet on it? ...)
i.e. - you 'could' be good to go - or - you 'could' throw your money and time away.
IMHO - get devices that others have used and set up with success.
I really think that - that one is down the wrong path for you.
Another issue? Your time is money as well. A little more? Sooner? From a reliable resource?
(So Sorry. I'm being a PITA.!)
P-J
i.e. - you 'could' be good to go - or - you 'could' throw your money and time away.
IMHO - get devices that others have used and set up with success.
I really think that - that one is down the wrong path for you.
Another issue? Your time is money as well. A little more? Sooner? From a reliable resource?
(So Sorry. I'm being a PITA.!)
P-J
Brickout
Well-Known Member
Looks like the temp is in Celsius as well.
A PID would be the wrong type of control for a freezer. It would short cycle the compressor and burn it out pretty quickly.
There are cheap ebay controllers that work well for freezer temp control, they include short-cycle protection timers. I use the STC-1000 and it's been working great for the past few months I've used it. Lots of info about it in the DIY section of the forum:
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/
There are many other threads on there about other assemblies too with that same controller. I picked up a couple since I'm using the same setup as a temp controller for a ferm wrap too.
There are cheap ebay controllers that work well for freezer temp control, they include short-cycle protection timers. I use the STC-1000 and it's been working great for the past few months I've used it. Lots of info about it in the DIY section of the forum:
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/
There are many other threads on there about other assemblies too with that same controller. I picked up a couple since I'm using the same setup as a temp controller for a ferm wrap too.
runningweird
Well-Known Member
a quick googling turned up the product manual: http://www.rkcinst.co.jp/english/pdf_manual/imnzc17e3.pdf
The SSR is a solid state relay that allows a low current rated device to control a high current load. In typical usage as a kettle element heater controller the PID (lowcurrent rated device) signals the SSR to allow power to the high current draw element to maintain a temperature.
My PID for boil kettle is set to a PWM cycle time of 4 seconds. I have my short-cycle timer on the freezer controller set to 10 minutes.
My PID for boil kettle is set to a PWM cycle time of 4 seconds. I have my short-cycle timer on the freezer controller set to 10 minutes.
I'v been running one of my freezer chests off a cheap ebay PID for two years now. It works great. At first I tried to use a SSR and the PID, but the rapid cycling of the PID would not allow the compressor to turn on. The one I got has a 10A relay for the high temp alarm, so I wired the power supply for the compressor through the high temp alarm. No SSR needed.
from looking at the manual runningweird posted the alarm on this PID is rated at 1A for 250VAC (or is it 3A?) , so this PID might not work too well to run the compressor off the high temp alarm.
Personally it was more hassle than it was worth, and setting the temp is some what of a chore. I'd go with a $50 ranco controller . Ive bought 4 from these guys over the years.
from looking at the manual runningweird posted the alarm on this PID is rated at 1A for 250VAC (or is it 3A?) , so this PID might not work too well to run the compressor off the high temp alarm.
Personally it was more hassle than it was worth, and setting the temp is some what of a chore. I'd go with a $50 ranco controller . Ive bought 4 from these guys over the years.
I am trying out a box with a MyPin TD4, a 40 amp SSR with a small heatsink. I get the deal with short cycling the compressor. I have used this box for gently heating a fermentation chamber in the winter with a heating pad, and the thermocouple taped under a layer of Reflectix foam. Works well, but I am doing some experiments to see if I can deal with this through the setting, on the PID. Goal is +- 1 degree fahrenheit, and at least 10 minutes of rest between compressor cycles. Hysteresis and Integral seem to be the critical variables.
I am experimenting with a 5 gallon bucket of water with a starting temperature of 70F, a K type thermocouple under 2 layers of Reflectix foam, and an old Kenmore 6 cubic foot chest freezer I got for $20. This would be close to a typical setup.
I am experimenting with a 5 gallon bucket of water with a starting temperature of 70F, a K type thermocouple under 2 layers of Reflectix foam, and an old Kenmore 6 cubic foot chest freezer I got for $20. This would be close to a typical setup.
augiedoggy
Well-Known Member
A $14 stc1000 variant with a built in relay and temp probe would be a way better choice for what your trying to do here... pids are not meant for this type of thing.
By increasing the thermal mass near the probe, the compressor cycles less frequently. Still a PITA to make work, and I haven't tried it yet with actual fermenting wort to see how well it handles heat from an actual fermentation. I can also see situations, particularly with some Belgian styles, where I would need to both heat and cool, first by heating to maintain pitching temperature in a cold basement, then cooling to contain temperature rises, then heating again to maintain the desired temperature as fermentation tapers off.
i will probably get an STC-1000 eventually, and consign my PIDs to running a -recirculation pump and heating elements for a HERMS or RIMS I eventually want to build.
i will probably get an STC-1000 eventually, and consign my PIDs to running a -recirculation pump and heating elements for a HERMS or RIMS I eventually want to build.
