## International Efficiency Marking Pr otocol for External Power Supplies

This fact sheet describes the international effi ciency marking protocol and its implementation under the ENERGY STAR Version 2.0 External Power Supply specification. Sources for additional information are provided on page 3. This version, updated as of October 2008, replaces an earlier
document released in 2005.

What is the international e fficiency marking protocol? The international efficiency marking protocol prov ides a system for power supply manufacturers to designate the minimum efficiency performance of an ex ternal power supply, so that finished product manufacturers and government representatives can easily determine a unit’s efficiency. This mark does

not serve as a consumer information label, but rath er demonstrates the perfor mance of the external power supply when tested to the internationally su pported test method (this test method titled “Test Method for Calculating the Energy Efficiency of Singl e-Voltage External Ac-Dc and Ac-Ac Power Supplies (August 11, 2004)” can be found at www.energystar.gov/powersupplies ).

What does the international efficiency mark look like? The international efficiency mark consists of a Ro man numeral (I – VI) that corresponds to specific minimum Active and No-Load efficiency levels (as well as a power factor requirement for level V) and is printed/applied by the manufacturer on the exte rnal power supply nameplate (or an equally visible location).

Format: Roman numeral: I, II, III, IV, V, or VI. Font: Times Roman preferred (or other plain serif fonts). Size: Legible and indelible. Color: Text to contrast with the nameplate ba ckground, unless incorporated in the case molding. Placement: Preferably on the power supply nameplate; however, exact location is at the discretion of the manufacturer. The text “Efficiency Level” shown below is optional. An example is provided below.

How is the international efficiency marking protocol being implemented? The nameplate (or an equally visible location) of si ngle voltage external ac-dc and ac-ac power supplies must be clearly and permanently marked with a Roman numer al from the sequence I (least efficient) to VI (most efficient) that corresponds to specific minimu m Active and No-Load efficiency levels (as well as a power factor requirement for level V). The performan ce requirements for each Roman numeral are shown
in the table below.

To determine the appropriate Roman numeral, manufact urers: 1) compare the unit’s Active, No-Load, and power factor test data (when tested in accordance with the ENERGY STAR Test Method and at each relevant test voltage and frequency value) with the pe rformance requirements at each level of the Roman

### numeral scale; and 2) choose the highest Roman nume ral where the power supply meets the Active, NoLoad, and power factor (where applicable) requirements.

Performance Requirements Mark

Nameplate Power Output (P no ) 1 No- Load
Power 2 Nameplate Power Output (P no ) Average Active Efficiency 3 Power Factor



### I Used if none of the other criteria are met.

0 to ≤ 10 watts ≤ 0.75 0 to < 1 watt ≥ 0.39 x P no > 10 to 250 watts ≤ 1.0 1 to < 49 watts ≥ 0.107 x Ln(P no ) + 0.39 

### II

> 49 watts ≥ 0.82 Not applicable

0 to < 10 watts ≤ 0.5 0 to 1 watt ≥ 0.49 x P no 10 to 250 watts ≤ 0.75 > 1 to 49 watts ≥ 0.09 x Ln(P no )+0.49 

### III

> 49 to 250 watts ≥ 0.84 Not applicable

0 to 250 watts ≤ 0.5 0 to < 1 watt ≥ 0.5 x P no 1 to 51 watts ≥ 0.09 x Ln(P no )+0.5 

### IV

> 51 to 250 watts ≥ 0.85 Not applicable

0 to < 50 watts ≤ 0.5 for ac-ac;

≤ 0.3 for ac-dc 0 to ≤ 1 watt Standard: ≥ 0.480 * P no + 0.140 Low Voltage 4 : ≥ 0.497 * P no + 0.067

≥ 50 to ≤ 250 watts ≤ 0.5 > 1 to ≤ 49 watts Standard: ≥ [0.0626 * Ln (P no )] + 0.622 Low Voltage: ≥ [0.0750 * Ln (P no )] + 0.561 

### V

> 49 to 250 watts Standard: ≥ 0.870 Low Voltage: ≥ 0.860 Power supplies with greater than or equal
to 100 watts input power must have a true power
factor of 0.9 or greater at
100% of rated

load when
tested at 115 volts @ 60Hz.



### VI

and higher Reserved for future use.



### What is the relationship between the international efficiency marking protocol and ENERGY
STAR? The ENERGY STAR program for External Power Supplie s requires that manufacturers mark their power supplies using the international efficiency marking protocol. Any external power supply meeting the performance requirements for level V and above would qualify as ENERGY STAR (Version 2.0). Power supplies with performance levels of I - IV woul d not qualify under the Version 2.0 ENERGY STAR specification, which takes effect on November 1, 2008.

The new federal US standard for external power supplie s (effective July 1, 2008) is identical to level IV above. This standard only requires compliance at 115 V/60 Hz.

1 P no is the Nameplate Output Po wer of the unit under test.

2 In Australia and New Zealand, AC -AC external power supplies are not required to meet the no load power requirements.

3 Ln refers to the natural logarithm.

4 A low voltage model is an EPS with a nameplate output voltage of less than 6 volts and a nameplate output current greater than or equal to 550 milliamps.

### What if my power supply meets different efficiency levels when tested at different voltage/frequency combinations? To qualify as ENERGY STAR, manufacturers are required to mark the nameplate (or an equally visible location) with the highest Roman numeral that the external power supply meets for Active and No-Load requirements at both voltage/frequency comb inations (115 V/60 Hz and 230 V/50 Hz) . EPA also has a power factor requirement under its Version 2.0 specification that only applies to power supplies with greater than or equal to 100 watts input power and when tested at 115 V/60 Hz.

Some organizations such as Australia’s Department of the Environment, Heritage and Arts (DEWHA), as well as the US Energy Independence and Security Act of 2007, have adopted a modified approach to this protocol, allowing manufacturers to mark an EPS capable of oper ating at multiple vo ltages/frequencies as meeting the requirements in only one voltage/frequ ency combination. This modified approach is not acceptable for marking a power supply for ENERGY STAR qualification , given the requirement to test and qualify power supplies capable of operating at multiple voltages/frequencies at both 115 V/ 60Hz and 230 V/50 Hz. For illustrative purposes, the table below provides some sample marks and an explanation of
each.

Sample Marks Explanation Mark indicating a power supply meets the level V requirements at both 115 V/60 Hz and 230 V/50 Hz, if desi gned to operate at multiple input voltages. Products with a nameplat e marked for only one voltage and frequency should also use this mark assuming the product meets the performance requirements; in other words, manufacturers do not have to indicate the voltage with the mark. Mark indicating a power supply meets the level V performance requirements only at 115 V/60 Hz (for power supplies also able to operate at 230 V/50 Hz). This mark shows compliance with the US mandatory standard, but not with the ENERGY STAR Version 2.0 specification.

Mark indicating a power supply meets the level IV performance requirements only at 115 V/60 Hz (for power supplies also able to operate at 230 V/50 Hz). This mark shows compliance with the US mandatory standard.

Mark indicating a power supply meets the level IV requirements at only 230 V/50 Hz (for power supplies also able to operate at 115 V/60 Hz).
This would be relevant for the Australian and New Zealand markets as their MEPS and High Efficiency performance requirements and mandatory marking only require testing and compliance at 230 V ac.

Dual marking for a power supply that meets different performance levels at different input voltages.



### For More Information

• On ENERGY STAR: Visit t he ENERGY STAR Web site at www.energystar.gov/powersupplies or contact Andrew Fanara, US EPA, at Fanara.andrew@epa.gov

.

• On US energy conservation standards: Visit t he US Department of Energy (DOE) Web site at http://www.eere.energy.gov/buildings/appliance_standards/residential/battery_external.html or contact Victor Petrolati, US DOE, at Victor.Petrolati@ee.doe.gov

.