ZWO ASI 533 will not cool

bellavia

I just received a brand new ZWO ASI 533 MC Pro, and it will only cool 20C below ambient, starting at 15 Celsius, and often takes several tries, restarting the cooling process from the previous temperature.

The specifications say it should cool 35C below ambient.

My ZWO ASI 183MM and 183MC both easily cool 40C below ambient, using the same power supplies and cables, which are rated to 10 amps.

I measured current draw, and at -5C it draws 0.55 amps, if that is of any use diagnosing this issue.

Thank you

Steven Bellavia

bellavia

bellavia wrote:

I just received a brand new ZWO ASI 533 MC Pro, and it will only cool 20C below ambient, starting at 15 Celsius, and often takes several tries, restarting the cooling process from the previous temperature.

The specifications say it should cool 35C below ambient.

My ZWO ASI 183MM and 183MC both easily cool 40C below ambient, using the same power supplies and cables, which are rated to 10 amps.

I measured current draw, and at -5C it draws 0.55 amps, if that is of any use diagnosing this issue.

Also note that I was not able to cool the camera using SharpCap, when connected with the native driver. And the temperature was climbing, so I disconnected.

Thank you

Steven Bellavia

bellavia

More tests today:

using APT:

1. I read the User Guide for APT, which states that if you enter "0" for cooling steps, it leaves the cooling to the driver

2. Downloaded the latest version of APT (3.8.4), that has the correct native driver (previous version would not connect with native driver)

It cooled to -15C very rapidly, and was using about 87% power.

But it wouldn't hold and the temperature started drifting back up. The camera felt warm to the touch, and power went to 100%

3. Switched the cooling step to 5C and hit "Start" again. But now it was at 100% power, and it would not cool below 12C.

using SharpCap:

1. Downloaded the latest version of SharpCap (v3.2.6298), that has the correct native driver (previous version DID connect with native driver, but would not cool at all, and was actually getting much hotter)

Same result. With a target temperature of -15C it stopped around -11.9C at 100% power

So 28C seems to be the lowest it will go below an ambient of 16C

moson

Do not worry, it is normal. The ASI533 can cool to 35 degrees under ambient at best, it is tested in room temperature 25 degree. When the ambient temperature gets lower, it will be difficult for it to get 35 degrees under ambient.

Here is a FAQ on our website about this problem for your reference. (https://astronomy-imaging-camera.com/faq)

And sensor will inevitably emit more heat when cooling nearly or at 100% , it will lead to temperature rise so we recommend you not to use the cooling at its full capacity.

And the ASI533 has larger poewr consumption than ASI183, that's why ASI533 will emit more heat than ASI183.

bellavia

Moson wrote:

Do not worry, it is normal. The ASI533 can cool to 35 degrees under ambient at best, it is tested in room temperature 25 degree. When the ambient temperature gets lower, it will be difficult for it to get 35 degrees under ambient.

Here is a FAQ on our website about this problem for your reference. (https://astronomy-imaging-camera.com/faq)

And sensor will inevitably emit more heat when cooling nearly or at 100% , it will lead to temperature rise so we recommend you not to use the cooling at its full capacity.

And the ASI533 has larger poewr consumption than ASI183, that's why ASI533 will emit more heat than ASI183.

Interesting.

I have contacted 7 other owners of the camera, and they can all cool from 20C to -15C

Did something change in the latest batch of cameras? A different Peltier cooler perhaps?

moson

Sorry there is no change in the latest batch of cameras.

Maybe you could check the fan runs normally or the voltage is enough.

You could try to test again by using our ASIStudio software.

bellavia

Moson wrote:

Sorry there is no change in the latest batch of cameras.

Maybe you could check the fan runs normally or the voltage is enough.

You could try to test again by using our ASIStudio software.

First I wanted to say thank you for all your responses thus far!

I am running ASI Studio right now. From +20C The lowest I could get the camera was -9.5C, at 100% cooling power, without images being taken.

So similar results as using other software. (APT and SharpCap).

At -5C, in that same 20C environment, it uses 60% power.

I know my power supplies and cables are very good (I have built them myself, and also tried off-the-shelf supplies as well as fully charged SLA batteries).

If I can consistently get -5C, I believe that may be fine, as the dark current on this camera, at -5C is actually the same or a little lower than my 183MM and 183MC are at -15C. My only concern is on a warm summer night, not being able to reach -5C and having to make a new dark frame library for 0C, which I would not be happy with.

Thank you again for all your help.

First Light:

https://www.astrobin.com/nfp1kt/

Second Light:

https://www.astrobin.com/wxreri/