Power Supply temperature rating

[Shrek]

I found it interesting that the rated temperature varies with power (within the same series)

• The 430W model is rated for 50°C
• The 500W model is rated for 40°C
• The 600W model is not rated for temperature

 

[dirtyferret]

different OEMs? Also the 430w has 430w in the copy but is labeled as 400w in the headline.

 

[Shrek]

Yes, it is confusing, I went with 430W as that is what is on the case.

The identical case made me think it was the same platform (HEC for the 500W)

 

[dirtyferret]

Yes, it is confusing, I went with 430W as that is what is on the case.

the 430w was made by HEC and no way it was 50c rated. I highly doubt that 400w is 50c rated, in fact that spec chart is from the HEC made 430w unit which wasn't all that great. It's lazy marketing on EVGA part and too many OEMs for unit procurement that probably overwhelmed them.

*edit, @Shrek if you go to the EVGA web site so you can see the word better it says "all load and regulation testing done at 50c" not that it is "rated for 50c".

 

[Shrek]

The 500W unit (the one I have) blows up on full load; there is an ebay auction for 7 such units (all bust)

• EVGA 500W Review - Another One (PSU) Bites the Dust (youtube.com)

as you already know from the thread I made on doubling the number of bridge rectifiers.

Disclaimer: do not mess with power supplies as the main capacitors can carry a lethal charge even when the supply is not plugged in.

 

[dirtyferret]

• EVGA 500W Review - Another One (PSU) Bites the Dust (youtube.com)

I know HEC made the EVGA 500B and from your video (I had the sound off) it looked like their platform as well and some truly half assed built quality. HEC is is not the worst but their bread and butter is in making mediocre PSU. I personally would treat all three of those units as 30c rated.

 

[Shrek]

I got the supply cheap and added a second bridge rectifier (as a match pair), so will throw caution to the wind.

 

[Bill_Bright]

The 400 model is not 80 PLUS certified so it make me wonder if they really are in the same series.

 

[ShrimpBrime]

Almost all Power supplies are rated 40c to 50c max operating temperature.

If it's not listed, probably best to assume 40c max.

 

[Bill_Bright]

Almost all Power supplies

"Almost" being the key word there. I note these are budget/entry level models. There are some PSUs rated less than 40°C so I would not assume anything if not published. It is my experienced if an important spec it not published, that means the actual value achieved by that device is nothing the makers are proud of - or else they (their marketing weenies) would hype it up.

That said, it should be noted this spec if for the ambient (room or inside the CPU case) temperature. In other words, the temperature of the air at the intake of the supply. 30°C (86°C) is not what I would consider a comfortable room temp. That said, 30°C rating should not be considered as "bad" (with all else equal), with a properly cooled case in a "normal" ambient temperature room. We must also consider that spec also implies the supply is operating at maximum load 24/7 in those thermal conditions - and that is not a normal scenario for the vast majority of home, office, or TPU users.

Still, if rated at 40°C, that would certainly suggest the PSU is more capable and if rated at 50°C, more capable still.

 

[Vya Domus]

Does this rating even mean anything IRL? I am not sure what it even refers to, if it means maximum ambient temperature 50C is pretty ludicrous, the exhaust out of your PC is going to be like 35-40C at most and it dissipates fast anyway, it's virtually impossible to have constant 40C+ intake temperature under normal circumstances.

 

[dirtyferret]

Almost all Power supplies are rated 40c to 50c max operating temperature.

If it's not listed, probably best to assume 40c max.

most quality power supplies are 40c or 50c, most power supplies are 30c or even 25c if rated at all. There are more bad and mediocre units than there are good units especially once you leave the NA market

Also, if its not listed I would never assume anything other than the brand/oem wants to avoid listing the temp rating.

Does this rating even mean anything IRL? I am not sure what it even refers to, if it means maximum ambient temperature 50C is pretty ludicrous,

it means what the brand/oem beleive the unit can do in terms of maintain its specs under the specific temp. What a lot of people go and buy is wattage but if you get a 750w bronze unit that can only maintain spec at 30c and put it in a gaming PC that going to be 45c than you really don't have a 750w unit.

 

[Shrek]

Does this rating even mean anything IRL? I am not sure what it even refers to, if it means maximum ambient temperature 50C is pretty ludicrous, the exhaust out of your PC is going to be like 35-40C at most and it dissipates fast anyway, it's virtually impossible to have constant 40C+ intake temperature under normal circumstances.

My room temperatures can reach 40°C in Summer and if the supply is exhausting case air it might experience even hotter intake air. I have a 500W supply, but my machine needs less than 250W max so for me that is derating enough for when things get toasty.

 

[agent_x007]

It's normal actually.
The more power goes through PSU, the more current the components need to handle, which in turn increases their heat dissipation (more current = more heat loss). That means, that at the same ambient temps, those components will be hotter/closer to their max. designed specs at higher power rating.
Which either needs to "get eaten" by less margin (ie. lower longevity/less stability), OR straight up get's over manufacturer's design limits for operating temp. range - requiring either a downgrade of capability (lower max. ambient temp), or increasing quality of components/PCB to compensate (both at which may not be possible to do, but always more expensive).

 

[ShrimpBrime]

most quality power supplies are 40c or 50c, most power supplies are 30c or even 25c if rated at all. There are more bad and mediocre units than there are good units especially once you leave the NA market

Also, if its not listed I would never assume anything other than the brand/oem wants to avoid listing the temp rating.


it means what the brand/oem beleive the unit can do in terms of maintain its specs under the specific temp. What a lot of people go and buy is wattage but if you get a 750w bronze unit that can only maintain spec at 30c and put it in a gaming PC that going to be 45c than you really don't have a 750w unit.

Yeah. You and Bill are right! Glad I use terms loosely like almost, not all, some, a few.... however you want to divide them numbers.

T-case delta max. That's what most people are reading on specs.

It is not the rating of internal hardware specs.
(Right? We are all on the same page then?)

Just because a PSU can operate in a higher temp environment doesn't mean it's "more capable". It just means it'll run in a warmer environment.

This 40c probably matters to those in a warm climate that don't condition their ambient air with an ambient air conditioner.

 

[Bobaganoosh]

Yeah. You and Bill are right! Glad I use terms loosely like almost, not all, some, a few.... however you want to divide them numbers.

T-case delta max. That's what most people are reading on specs.

It is not the rating of internal hardware specs.
(Right? We are all on the same page then?)

Just because a PSU can operate in a higher temp environment doesn't mean it's "more capable". It just means it'll run in a warmer environment.

This 40c probably matters to those in a warm climate that don't condition their ambient air with an ambient air conditioner.

Usually it has to do with how good the heatsinks and cooling are on the internal components in terms of how well they stay within their own temperature ratings at given ambient temps. It doesn't mean that the FETs, caps, etc. inside are rated 40-50C, but at that ambient temperature, they expect the internal part with a 105C rating (for example) to stay below 105C at full load (and not let out the magic smoke that you're supposed to keep inside the components...they can't work right if you let the smoke out).

This is only meant as clarification, not disagreement with what most folks here have already said. I'd be pretty cautious of EVGA's budget PSUs. Many of their high-end ones were great back in the day, but the cheapos were...well...super cheap and not made to last for the most part. I mean from their perspective they'd probably say "hey, it's a $40 PSU, what do you want?" lol, but there are other companies with more reliable cheap supplies.

All that said, it's just one more reason to slightly over-do it on the power supply's ratings for your application. The ambient tests they do are going to likely be in a thermal chamber with airflow. Will it perform exactly the same as it will in the basement of your PC, with a clogged air filter, under a shroud, etc.? I don't know. What I do know is that it's probably seeing a warmer "ambient" in that chamber for most people than the rest of the PC is. Some cases have been utilizing great vents and airflow for the power supply, but as they get more efficient (for the high-end models anyway), it seems like case manufacturers are sometimes closing them off more and more, so you really don't want to just ignore it.

 

[dirtyferret]

I'm not debating here just clarifying for others who may read this

It is not the rating of internal hardware specs.
(Right? We are all on the same page then?)

No it's not the rating of internal hardware and some of it is marketing but let's take the Seasonic A12 500w 80plus unit as an example which rated for 0 to 40c. What Seasonic is saying is that unit will remain 80 plus efficient and remain within ATX spec up to 40c. Now can it do that in temps at 45c or more? Maybe or maybe not, we would need to rely on a reviewer who knows how to test PSU properly under those conditions.

Just because a PSU can operate in a higher temp environment doesn't mean it's "more capable". It just means it'll run in a warmer environment.

Both can be true. It really depends on the exact PSU in discussion but if we are talking about a 30c rated PSU compare to a 50C rated PSU one would certainly make the "more capable" distinction for the 50c rated. Virtually all of the top tier lines from brands that do battle for "best of" will be 0 to 50c rated.

The ambient tests they do are going to likely be in a thermal chamber with airflow.

80 plus does their tests at room temp so just because said unit has 80 plus gold on the box does not necessarily mean it will do gold in a hot PC case which is why good reviewers will test PSU in hot chambers.