STC-1000 Very Odd Behavior

[hennesse]

I've been using an STC-1000 temperature controller on my ferm chamber for a couple of months. It works great, but I found an odd problem that might affect people who live in areas that get those annoying 1-second power outages - like me.

When the STC-1000 is running, the power goes out and then comes back on, the unit resumes normal operation with all the saved settings intact. Great - that's exactly what it should do.

If I turn off the STC-1000, by holding down the power button until it turns off, and THEN the power goes out and then comes back on - guess what - it starts up in normal operation.

Yikes! This is the wrong thing for it to do. If it's off, it should stay off.

So if you're not using your ferm chamber for awhile, you might want to unplug your STC-1000.

Imagine you're "between batches" and you shut off the STC-1000 and leave the fridge door open so it can air out. A little power blip, and you're trying to heat or cool the entire planet. Especially if it's out in your garage or someplace where you don't notice until it's been running full blast for weeks!

Maybe my unit is defective. Can someone else verify (turn the STC-1000 off, unplugging it, and plugging it back in) whether this odd behavior happens to all STC-1000's?

Dave

 

[raouliii]

The STC1000 is not sophisticated enough to store its current ON/OFF state. However, it is sophisticated enough that it powers up to an ON state when AC power is applied, which is the best option, especially if you are actively using it for temperature control.

I unplug my controllers if I am not using the device they control, in particular, my fermentation chamber. I let my fermentation chamber slowly warm up with the door closed and the evaporator fan running. Once it is at room/ambient temperature, I open the door and block it. This procedure reduces the amount of moisture that is drawn into the chamber.

 

[Brumateur]

Use an external Power switch. It costs less than a dollar.

 

[hennesse]

The STC1000 is not sophisticated enough to store its current ON/OFF state. However, it is sophisticated enough that it powers up to an ON state when AC power is applied, which is the best option [...]

I vehemently disagree. The unit has NVRAM to store its operating parameters, so it easily could - and should - store its On/Off state.

Imagine if you had a similar microprocessor controlled gizmo in your factory controlling an electric saw or a 100-ton press. A worker turns the machine off, starts performing maintenance, a power flicker occurs, the machine starts, and the worker has just lost an arm. This is NOT the "best option".

Many power tools - like circular saws - do NOT have a trigger-lock. This not only provides a "deadman's throttle" during operation, but also provides "safe-start".

It would have been a simple matter for the designers to incorporate "Return to Last State" in the microprocessor's logic. Perhaps that would have added a dollar to the cost, but they would have produced a safe-start controller.

WARNING: MACHINE STARTS UNPREDICTABLY

 

[augiedoggy]

I vehemently disagree. The unit has NVRAM to store its operating parameters, so it easily could - and should - store its On/Off state.

Imagine if you had a similar microprocessor controlled gizmo in your factory controlling an electric saw or a 100-ton press. A worker turns the machine off, starts performing maintenance, a power flicker occurs, the machine starts, and the worker has just lost an arm. This is NOT the "best option".

Many power tools - like circular saws - do NOT have a trigger-lock. This not only provides a "deadman's throttle" during operation, but also provides "safe-start".

It would have been a simple matter for the designers to incorporate "Return to Last State" in the microprocessor's logic. Perhaps that would have added a dollar to the cost, but they would have produced a safe-start controller.

WARNING: MACHINE STARTS UNPREDICTABLY

I really dont think this $13 no name chinese controller is something that would be used in a machine like that were someones life would be a factor....
Let put things in perspective here... This is a small inconvenience... but my biggest inconvenience if I were in your shoes would be addressing the poor unstable power... Maybe thats one of the reasons its only 13 dollars and not $50?
For me a powerstrip with its own switch is the plan.

 

[raouliii]

I vehemently disagree. The unit has NVRAM to store its operating parameters, so it easily could - and should - store its On/Off state....

My post simply made a statement that the STC1000 does not possess that level of sophistication. Could it? Sure. I guess they missed that option when writing the code. It's a cheap digital temperature controller.

If the ONLY options for loss of input power were to restart back to its current operational parameters OR not power on at all, the first option is better, imo, considering its labeled application. I will check the behavior of my unit.

I can't conceive of a situation, but would certainly question their intelligence, where one would choose to use a cheap digital temperature controller to control an electric saw or hydraulic press. Or any other dangerous machine, for that matter.

Vehement? Really, Dave? RDWHAHB

 

[ReddHead]

Interesting. I always unplug mine when not in use because it is a parasitic electrical draw and we tend to get a lot of brown outs and I'm afraid of frying something.

I'm switching from heating to cooling tonight so I am going to try to remember and test this behavior.

 

[ChuckO]

Just tested my STC-1000 and it stayed off after being unplugged and plugged back in. That's the way I expected it to work. I had not noticed any other behavior in the last two years that it's been running my fermenter.

 

[ReddHead]

I tested mine and it turns on and enters cooling mode, even though it was turned off. So, OP is not crazy.