Can We Trust the 80 Plus Certification?

[Hardware Secrets Team]

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Title: Can We Trust the 80 Plus Certification?
URL: http://www.hardwaresecrets.com/article/856

Here is a snippet:
"The 80 Plus certification was an important step to change the scenario from the power supply industry: now the savvy consumer knows that he or she should buy a power supply with at least 80% efficienc..."

Comments on this article are welcome.

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Hardware Secrets Team
http://www.hardwaresecrets.com

[Olle P]

The temperature issue is real, but not as absolute as suggested.
Many computer cases are designed to provide the PSU with fairly cool air, either directly from outside the case or via some minor heat source.

Another aspect is the efficiency at low power output. The 80 Plus standard only go down to 20% of the PSU's rated maximum, which may very well be much above the computer's "idle" consumption.
In this region the efficiency is also much lower than it is at 50% output.

Finally, another "cheat" in the 80 Plus testing is that the test is done at 230V input voltage (provided the PSU is supposed to support that voltage at all). That will usually provide an efficiency some 2-5% units better than if the PSU is fed 115V.

In all I still think the 80 Plus certification is a step in the right direction. To improve it there should also be additional requirements for the efficiency at higher temperatures, like 45C, as well as for fixed lower output levels, like 10, 20 and 40 watts.

Cheers
Olle

[Gabriel Torres]

Nice comments, Olle P. As they are based in the USA they should be testing at 115 V...

Cheers,
Gabriel.

[Merman]

I agree that the 80Plus temperature standards should be upgraded. Especially since it seems like the best suppliers of PSU have already met higher standards.

Read what was said of the first PSU, Seasonic of course, to meet 80Plus standards in 2005.
http://www.80plus.org/docs/press/Fir...wer_Supply.pdf

“When we started the 80 Plus program last year, we knew we had set the bar for energy efficiency high,” said Chris Calwell, Ecos Consulting’s director of policy and research and technical advisor for the 80 Plus program. “The market has been racing to respond. Seasonic got there first, and we congratulate them for this outstanding achievement.”

“We are delighted that the Seasonic SS-400HT ATX12V v2.0 is the first power supply in the world to be certified 80 Plus compliant,” said Vincent Chang, product manager at Seasonic. “The 80 Plus certification test is very demanding, particularly the 80 percent efficiency at 20 percent load requirement. For a 400-watt power supply unit, this is only 80 watts. High efficiency at such low power is difficult to reach, so this is an achievement our engineers can be especially proud of.”

[Travis]

Since 80Plus is in NA, they test PC power supplies at 115VAC, not 230VAC.

Originally Posted by Olle P

Finally, another "cheat" in the 80 Plus testing is that the test is done at 230V input voltage (provided the PSU is supposed to support that voltage at all). That will usually provide an efficiency some 2-5% units better than if the PSU is fed 115V.

Cheers
Olle

[Merman]

According to their web site 115V is used for "power supplies certified for desktop, workstation and non-redundant server applications."

http://www.80plus.org/manu/psu/psu_join.aspx

[Olle P]

Originally Posted by Merman

According to their web site 115V is used for "power supplies certified for desktop, workstation and non-redundant server applications."

Not as I read it...
That list seems aimed at the domestic market and divided in two mostly based on what input can be used in an environment where most outlets are 115V.

The actual test protocol states:

Originally Posted by Page 15

4.2.1 Ac Input Voltage and Frequency
An ac reference source shall be used to provide input voltage to the UUT. As is specified in IEC 62301, the input to the UUT shall be the specified voltage ± 1% and the specified frequency ±1%. The UUT shall be tested at one of two voltage and frequency combinations: 115 V at 60 Hz or 230 V at 60 Hz.

The UUT shall be tested at one of the above voltage and frequency combinations that is closest to its nameplate input voltage and frequency. If voltage and/or frequency ranges are not specified by the manufacturer (or the nameplate value is unclear), the UUT shall not be tested.

IMO the specified "closest to its nameplate input voltage" is a bit vague.
Since most PSUs are rated 110-240V (or even wider range) any of the specified voltages is valid.
My gut feeling is that if they didn't use the higher voltage for the actual test (reading "nameplate input voltage" as the higher value in the range) some PSU manufacturers would get very upset...

Cheers
Olle

[Merman]

Originally Posted by Olle P

Not as I read it...
That list seems aimed at the domestic market and divided in two mostly based on what input can be used in an environment where most outlets are 115V.

The actual test protocol states:
IMO the specified "closest to its nameplate input voltage" is a bit vague.
Since most PSUs are rated 110-240V (or even wider range) any of the specified voltages is valid.
My gut feeling is that if they didn't use the higher voltage for the actual test (reading "nameplate input voltage" as the higher value in the range) some PSU manufacturers would get very upset...

Cheers
Olle

There is only one way to read that list. Power supplies tested at 115V and those tested at 230V. The test protocol you quote also states:

4.2.1 Ac Input Voltage and Frequency
An ac reference source shall be used to provide input voltage to the UUT. As is specified in IEC 62301, the input to the UUT shall be the specified voltage ± 1% and the specified frequency ± 1%. The UUT shall be tested at one of two voltage and frequency combinations: 115 V at 60 Hz or 230 V at 60 Hz.

The UUT shall be tested at one of the above voltage and frequency combinations that is closest to its nameplate input voltage and frequency. If voltage and/or frequency ranges are not specified by the manufacturer (or the nameplate value is unclear), the UUT shall not be tested.

UUT is Unit Under Test.

The 80Plus application also makes the point of what voltage the unit is to be tested.
http://www.80plus.org/manu/psu/psu_application.aspx

Here is what 80Plus is about on there about page:

What is 80 PLUS®

80 PLUS is an innovative, electric utility-funded incentive program to integrate more energy-efficient power supplies into desktop computers and servers. Participating utilities and energy efficiency organizations across North America have contributed over $5 million of incentives to help the computer industry transition to 80 PLUS certified power supplies.

To date, over 1300 power supplies have been certified and many local and major computer manufacturers are selling qualified computers. Additionally, large commercial and institutional consumers are specifying 80 PLUS in their procurement policies at increasing rates.

80 PLUS now certifies power supply products for high efficiency performance in server applications with the inclusion of a category of testing for Redundant Single Output server power supplies.

Industry efficiency performance has improved dramatically over the four years of 80 PLUS' existence enabling 80 PLUS to announce higher efficiency levels of Certification (Bronze, Silver, Gold)

They are catering to the North American market. Doesn't that mean 115V???

The last point is, this is the list of 80Plus certified PSU. If you look at the Efficiency Report for a certified PSU, under the Rated Specifications for the tested unit is the voltage used.