Hello I have a new 1515 that we just got up and running. I'm very new to all this and working on getting up to speed by asking lots of (often dumb) questions. I very much appreciate having this forum toward that end. My latest question is this... I have not once seen the fan in my power supply come on. Granted, the 1515 is set up in my unheated shop, but it doesn't get super cold in there, usually in the lower 50s at the coldest. Should that fan be coming on only after hitting some determined temperature, or should it be on all the time like my Black Box that is running all the time it's turned on? Everything is working fine, but I still wonder why there is a fan in that power supply if it never comes on?