jAMBAZZ Posted November 21, 2013 Share Posted November 21, 2013 Room temperatures are typically much lower than internal PC temperatures, so there shouldn't be a problem unless the room temperature is unusually high (say, over 35°C). The fault was discovered when ambient temps were much higher (45°C) and without airflow, thus creating a smaller delta between ambient and operating temperature. Since the fan operates on both temperature and time delay, the temperatures raised too quickly for the fan controller to operate the fan. The ambient temperature of the room alone should be enough to maintain a lower operating temperature, so even prolonged operation at higher loads should give the fan controller adequate time to turn on the fan. Actually, no. While some fanless units have orientation requirements, the RM Series can be mounted in any position just like any other actively cooled power supply. Some fanless PSUs require a certain mounting orientation because they use the housing as a heatsink that needs to be exposed to the aspiration within the case or have vent holes that need to circulate air to/from the outside of the chassis. But keep in mind, these PSUs are made to run at 100% load without a fan. The RM cannot and should not operate anywhere near 100% without the fan turning on. Jonny I have some questions/assumptions I hope you could look at before I return my 750RM as my SN is 1333. :[pouts: In all these assumptions, I assume that the PSU FAN is not spinning, because in my system, that draws 360W, I have not yet seen the fan spin. My first understanding is that the PSU will shut down if the PSU temp is too high. This can happen if the ambient (room) temp is > 45C. But if the airflow in the PSU is good, because of case architecture, PSU should be OK. PSU could also shut down when the ambient (room) temp is fine, but the case temp is very high (>45C), this could happen in "traditional" cases with very bad airflow, specifically where the PSU is top and rear mounted, because the hot case air convects up and into the PSU, adding more heat to the PSU which it self is already warm because its fans are not spinning. Can you clarify when the FAN will turn on in PSUs prior to SN=1345? As I understand, it will only spin if load >= 40%, regardless of PSU temperature, correct? If the PSU is bottom-mounted in a case where it intakes air from the floor and the PSU section of the case is cut off from the rest of the case, then the PSU sucks in room temp air, and as long as this is not >= 45c this situation will be dandy, because the case airflow cannot impact the PSU temp. I my assumptions are true, I cannot see why I should RMA my 750RM. I just have to either: Monitor the case temp so that is not >45CUse more power in which case the PSU fan will spin and remove air thus reducing temps to safe levels.OR get a new case with bottom mounted PSU that intakes air from floor. My specs: Antec Sonata I, PSU rear and top mounted. Intake fan: 120 mm 36/74 CFM (low/high) Exhaust fan: 120 mm 36/74 CFM (low/high) i5 2500K overclocked GeForce 670GTX overclocked Combined wattage at max load 375 W (3 threads of small FFT Prime95 + Furmark burn-in) Link to comment Share on other sites More sharing options...
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