Have had at least 6 fans fail in the past 18 months on various installations which are within 5km of the ocean. Would like to replace these with IP67 units which are 12V 0.27A. The original fans are 12V-0.195A. Would the RS450/200 support both fans on the Batt Side at 0.27A?
The main issue isn’t the fan’s IP rating, but the humidity itself, along with the quality of the ball bearings and their lubrication. The problem is specifically that corrosion is damaging this assembly.
ARCTIC has some decent models with dual ball bearings and shaft rotation stabilisation, which significantly reduces wear. Have a look through their range of dual-bearing fans, there’s quite a bit to choose from in terms of specifications and rotational speed.
UPD: CO series - Continuous Operation
The fan’s motors fail within 12~18 months. The fan itself still turns very smoothly by hand. So it seems that the circuit board in the fan is getting corrosion and failing. IP68 should hopefully take care of that. Just need to know if we can put a two fans which are 3.24W each instead of the original 2.34W without damage to the circuit board
I’ve run into the same problem a couple of times on the 450/200 TR. The solution was to replace it with an Arctic, specifically the 7,000 RPM model with a power consumption of 6 W, and there were no further problems. The MPPT itself was actually cooled even better due to the more active airflow. I don’t remember the exact figures anymore, but if my memory serves me right, the cooling system’s power conversion module in the 450/100 and 450/200 is designed for up to 1.5 or 2 A. I can’t remember exactly.
There are protective sprays, such as conformal coatings, that can protect PCBs from corrosive environments. Why aren’t Victron’s marine devices generally treated with such a coating? Or are they already?
The RS450 isn’t exactly a marine device.
I’d actually put it differently: it’s not marine at all, the further away from water and moisture, the better 
But they’re very good controllers in their own right, and for any installation I’d prefer 2 x 450/100 rather than 1 x 450/200.