ZWO Camera won’t cool


I’m using the latest version of SGP with an ASI183MC camera, and when I set the temp to go down to -15C, I cannot seem to go below -10C. When I use the camera in Maxim, it cools down no problem. Any ideas?


I have been using the ASI183mm Pro with the latest and previous versions of SGP and it’s been working wonderfully. Have you considered the camera’s max delta T cooling? I think it is good for about -45 degrees for mine. Where I am, I set SGP for -20 in winter and -15 for summer. Sometimes, it’s pretty late before it gets below 30 outside.

Other than that, ZWO does have an issue with an internal power connector that can easily be fixed by bending the pins on the connector. The typical symptoms for that problem though are an apparently dead TEC. I have a previous post on the details of this and the fix.



When I use Maxim and turn on the cooler, the temp proceeds directly to the set point. In SGP, it takes its sweet time (regardless of the setting), and then it floats around. For example, I have it set to -15 (and I’m indoors) and the temp goes to -15, then it drifts to -11, then back to ,13, etc.


Very strange indeed. SGP can be set to cool down in some time period, say 5 or 10 min. I have seen it set intermediate temps to go to during that time and eventually stabilize on the setpoint. Other than that, I am out of ideas.

Typically mine stays rock solid at -15.0 when the power percentage is less than 100%.
Here is a pic of mine tonight using 32% of the cooling capability.


Do you have a non-zero value in the “Change Over” field? This can certainly slow things down if you just want your camera to get to temp ASAP:


Or are you using the “Cool down” option below that?



I have a zero in there and I am not using the cool down option. The temp will get down to -15, but then it will drift to -13, up to -16, etc over the course of a few hours. Maybe it’s the camera but I don’t know if I ever saw this behavior in Maxim.


SGP just tells the camera the temperature to hit and everything else is up to the camera. The only thing that changes this is if you’re using the cool down options.