is this for real ?
- Thread starter fugley
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The original post leaves out a lot of the nuance on this topic, as it neglects to mention the orientation of the enclosure the PSU is installed in, which determines the final operating orientation of the PSU.
Obviously, if you mount the PSU incorrectly, the hamster wheel efficiency is far less than ideal, though I'd hesitate to put such a low a percentage on it... the rodent torque coefficient drops dramatically in some orientations.
Really, power supplies are subject to derating for thermal reasons, and orientation affects convection... so if you do not mount the PSU as specified, then the manufacturer's derating curve may not be accurate. Interestingly, horizontal is the orientation specified in a datasheet such as that of the LRS-350 https://www.meanwell.com/productPdf.aspx?i=459... though it's easy to miss that it says (HORIZONTAL) in fine print below and to the right of the thermal derating chart. If you aren't sure, check the data sheet for your own PSU, as this varies. If your ambient enclosure temp is way below the derating point, or continuous load excepting a few short bursts is well below the PSUs rating, don't worry about it. And, if you notice your PSU is derating itself, take steps to improve airflow in its vicinity.
Obviously, if you mount the PSU incorrectly, the hamster wheel efficiency is far less than ideal, though I'd hesitate to put such a low a percentage on it... the rodent torque coefficient drops dramatically in some orientations.
Really, power supplies are subject to derating for thermal reasons, and orientation affects convection... so if you do not mount the PSU as specified, then the manufacturer's derating curve may not be accurate. Interestingly, horizontal is the orientation specified in a datasheet such as that of the LRS-350 https://www.meanwell.com/productPdf.aspx?i=459... though it's easy to miss that it says (HORIZONTAL) in fine print below and to the right of the thermal derating chart. If you aren't sure, check the data sheet for your own PSU, as this varies. If your ambient enclosure temp is way below the derating point, or continuous load excepting a few short bursts is well below the PSUs rating, don't worry about it. And, if you notice your PSU is derating itself, take steps to improve airflow in its vicinity.
The biggest issue with your question is calling the power supplies transformers. The supplied photo of the 2 power supplies has a fan immediately to the right of the lower supply so it's unlikely any derating would be needed. The lower power supply has the fan facing down which means that it's battling against convection cooling. Hot air rises and the fan is pushing the heated air back down where it will continue to rise. Forced air cooling of enclosures allows a multitude of sins to be forgiven. The steel enclosure and mounting pan will assist in getting rid of heat (unless the enclosure is in direct sunlight). As M.O.C. states the ambient temperature will affect the derating as well. In US/Canada/UK with Christmas being in winter the temps can easily be below 0C and cooling isn't much of an issue. In Aus/NZ Christmas is mid summer and it's often 20-40C ambient when the lights get turned on.
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could almost imagine hundreds of people now running outside with spirit level to get the optimal performance 
as a male though I generally don't read manual unless I'm seeing pending doom and then that'd be weeks later
releasing heat would of been my only thought on this matter to be fair
i thought it was kind of interesting and food for thought if anyone's hamsters a little off level and not performing
maybe i should read the user manual sometime
as a male though I generally don't read manual unless I'm seeing pending doom and then that'd be weeks later
releasing heat would of been my only thought on this matter to be fair
i thought it was kind of interesting and food for thought if anyone's hamsters a little off level and not performing
maybe i should read the user manual sometime
The user manual is super unhelpful on this ... quite expected though since each situation is different and the manufacturer can't possibly try them all. Just says (see: https://www.meanwell.com/Upload/PDF/Enclosed_Type_EN.pdf):
Those spec sheets, in turn, say hardly anything about how the orientation affects derating.
If it thermal trips, add ventilation or move some props over to the next PSU/controller... that's what I'd do. (No. Reducing brightness is NOT an option. Next idea please.)
But if you ever wanted the torque specifications for the mounting or terminal screws, now you have them. You're welcome.
Those spec sheets, in turn, say hardly anything about how the orientation affects derating.
If it thermal trips, add ventilation or move some props over to the next PSU/controller... that's what I'd do. (No. Reducing brightness is NOT an option. Next idea please.)
But if you ever wanted the torque specifications for the mounting or terminal screws, now you have them. You're welcome.
