My ASI533MC only achieves a maximum Delta temp of 30deg at 100% power. Even then it isn't very stable unless set for a maximum Delta of 25deg (eg set at 0deg when night temp is 25deg).
I use a 12v 8amp power supply and have other ZWO 1600 that work fine and easily cools another 15deg further at the same power on the same night. Strangely a friend's OSC also doesn't cool as well as our mono cameras? Does this seem normal, and do OSC cameras use same size Peltier cooler as colour versions?