EFFICIENCY STANDARDS

for external power supplies


Efficiency Standards
Efficiency standards icon

Focusing on Efficiency

The global regulatory environment surrounding the legislation of external power supply efficiency and no-load power draw has rapidly evolved over the past decade since the California Energy Commission (CEC) implemented the first mandatory standard in 2004. With the publication in 2014 of a new set of requirements by the United States Department of Energy (DOE) that took effect in February 2016, the landscape has changed again as regulators further reduce the amount of energy that may be consumed by external power adapters. In Europe, even more stringent requirements, which are currently voluntary, look set to become mandatory Ecodesign rules from January 2018. To help our customers stay on top of these continuously evolving global regulations, we have set out to push the energy efficiency initiative across our entire power portfolio. By continually monitoring the latest energy efficiency regulations, we ensure that not only our products, but our customers’ products are in compliance in each region where they are sold.

Level VI Products

Level VI Products

Browse CUI's portfolio of DoE Level VI and CoC Tier 2 external ac-dc power supplies.
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A Brief History

The infograph below traces the path from the CEC’s 2004 regulation through to the DoE’s Level VI standards that went into effect in early 2016. It also shows the European Union’s Code of Conduct standards that are voluntary now, but are currently under review to become Ecodesign requirements in two tiers. The Tier 1 standard, which is broadly equivalent to Level VI, is proposed to become mandatory from January 2017 and the tighter Tier 2 standard is proposed to become mandatory from January 2018.


timeline infographic for external power efficiency standards

The above timeline demonstrates just how dynamic the regulatory environment has been over the past several years. As different countries and regions enact stricter requirements and move from voluntary to mandatory programs, it has become vital that OEMs continually track the most recent developments to ensure compliance and avoid costly delays or fines. While many countries are establishing voluntary programs harmonized to the international efficiency marking protocol system first established by Energy Star, the following countries and regions now have regulations in place mandating that all external power supplies shipped across their borders meet the specified efficiency level:


LEVEL COUNTRY
VI United States
V European Union
IV Canada

The international efficiency marking protocol defines two performance criteria; no-load power consumption and energy efficiency. The table below summarizes the performance thresholds for each efficiency level as they were established over time:


LEVEL NO-LOAD POWER REQUIREMENT AVERAGE EFFICIENCY REQUIREMENT
I used if you do not meet any of the criteria
II no criteria was ever established
III ≤10 Watts: ≤0.5W of No Load Power
10~250 Watts: ≤0.75W No Load Power
≤1 Watt: ≥ Power x 0.49
1~51 Watts: ≥[0.09 x Ln(Power)] + 0.49
49~250 Watts: ≥84%
IV 0~250 Watts: ≤0.5W No Load Power ≤1 Watt: ≥ Power x 0.50
1~51 Watts: ≥[0.09 x Ln(Power)] + 0.5
51~250 Watts: ≥85%
V Standard Voltage Ac-Dc Models (>6Vout)
0~49 Watts: ≤0.3W No Load Power
50~250 Watts: ≤0.5W No Load Power
≤1 Watt: ≥ 0.48 x Power + 0.140
1~49 Watts: ≥[0.0626 x Ln(Power)] + 0.622
50~250 Watts: ≥87%
Low Voltage Ac-Dc Models (<6Vout)
0~49 Watts: ≤0.3W No Load Power
50~250 Watts: ≤0.5W No Load Power
≤1 Watt: ≥ 0.497 x Power + 0.067
1~49 Watts: ≥[0.0750 x Ln(Power)] + 0.561
50~250 Watts: ≥86%
The term "power" means the power designated on the label of the power supply.

Complying with DoE Level VI

In addition to tightened regulations for existing adapters, DoE Level VI expands the range of products that fall under the standard. Regulated products now include:

  • Multiple-voltage external power supplies
  • Products with power levels > 250 watts

The performance thresholds are summarized in the table below:

Single-Voltage External Ac-Dc Power Supply, Basic-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.5 x Pout + 0.16 ≤ 0.100
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout) - 0.0014 x Pout + 0.67 ≤ 0.100
49 W < Pout ≤ 250 W ≥ 0.880 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500

Single-Voltage External Ac-Dc Power Supply, Low-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.517 x Pout + 0.087 ≤ 0.100
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout) - 0.0014 x Pout + 0.609 ≤ 0.100
49 W < Pout ≤ 250 W ≥ 0.870 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500

Single-Voltage External Ac-Ac Power Supply, Basic-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.5 x Pout + 0.16 ≤ 0.210
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout) - 0.0014 x Pout + 0.67 ≤ 0.210
49 W < Pout ≤ 250 W ≥ 0.880 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500

Single-Voltage External Ac-Ac Power Supply, Low-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.517 x Pout + 0.087 ≤ 0.210
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout) - 0.0014 x Pout + 0.609 ≤ 0.210
49 W < Pout ≤ 250 W ≥ 0.870 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500

Multiple-Voltage External Power Supply
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.497 x Pout + 0.067 ≤ 0.300
1 W < Pout ≤ 49 W ≥ 0.075 x ln(Pout) + 0.561 ≤ 0.300
Pout > 49 W ≥ 0.860 ≤ 0.300

Exemptions


The Level VI mandate defines exemptions for EPS products. The direct operation EPS standards do not apply if:

It is a device that requires Federal Food and Drug Administration listing and approval as a medical device in accordance with section 360c of title 21;
OR
A direct operation, ac-dc external power supply with nameplate output voltage less than 3 volts and nameplate output current greater than or equal to 1,000 milliamps that charges the battery of a product that is fully or primarily motor-operated.

EU CoC and Ecodesign Requirements

The European Union published its Code of Conduct on Energy Efficiency of External Power Supplies Version 5 in October 2013. Tier 1 effectively harmonizes the EU with DoE Level VI, noting the differences in scope detailed below, and became effective as a voluntary requirement from January 2014, some two years ahead of Level VI. Its adoption as an EU Ecodesign rule is expected to be mandated from January 2017. The more stringent Tier 2 became effective on a voluntary basis from January 2016 and is expected to become mandatory as an Ecodesign rule from January 2018.

The key difference between the CoC requirements and Level VI is the new 10% load measure, which imposes efficiency requirements under a low-load condition where historically most types of power supplies have been notoriously inefficient. It is important to note that CoC does not distinguish between direct and indirect operation external power adapters. While CoC Tier 1 includes the new 10% load measure, its no-load and active mode limits are less stringent than DoE Level VI.

CoC Tier 2 further tightens the no-load and active mode power consumption limits for key classes of power adapters enacted by Level VI i.e. at output powers ≤49 W and 49 W < Pout ≤ 250 W and covers both standard voltage and low voltage adapters. The table below details the additional requirements imposed by Tier 2.

CoC Tier 1 Single-Voltage External Ac-Dc Power Supply, Basic-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
10% Load Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
0.3 W ≤ Pout < 1 W ≥ 0.50 x Pout +0.146 ≥ 0.50 x Pout +0.046 ≤ 0.150
1 W < Pout ≤ 49 W ≥ 0.0626 x ln(Pout) + 0.646 ≥ 0.0626 x ln(Pout) + 0.546 ≤ 0.150
49 W < Pout ≤ 250 W ≥ 0.890 ≥ 0.790 ≤ 0.250
Pout > 250 W N/A N/A N/A

CoC Tier 1 Single-Voltage External Ac-Dc Power Supply, Low-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
10% Load Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
0.3 W ≤ Pout < 1 W ≥ 0.50 x Pout +0.086 ≥ 0.50 x Pout ≤ 0.150
1 W < Pout ≤ 49 W ≥ 0.0755 x ln(Pout) + 0.586 ≥ 0.072 x ln(Pout) + 0.50 ≤ 0.150
49 W < Pout ≤ 250 W ≥ 0.880 ≥ 0.780 ≤ 0.250
Pout > 250 W N/A N/A N/A

CoC Tier 2 Single-Voltage External Ac-Dc Power Supply, Basic-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
10% Load Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
0.3 W ≤ Pout ≤ 1 W ≥ 0.50 x Pout + 0.169 ≥ 0.50 x Pout + 0.060 ≤ 0.075
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout) - 0.00115 x Pout + 0.670 ≥ 0.071 x ln(Pout) - 0.00115 x Pout + 0.570 ≤ 0.075
49 W < Pout ≤ 250 W ≥ 0.890 ≥ 0.790 ≤ 0.150
Pout > 250 W N/A N/A N/A

CoC Tier 2 Single-Voltage External Ac-Dc Power Supply, Low-Voltage
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
10% Load Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
0.3 W ≤ Pout ≤ 1 W ≥ 0.517 x Pout + 0.091 ≥ 0.517 x Pout ≤ 0.075
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout) - 0.0011 x Pout + 0.609 ≥ 0.071 x ln(Pout) - 0.00127 x Pout + 0.518 ≤ 0.075
49 W < Pout ≤ 250 W ≥ 0.880 ≥ 0.780 ≤ 0.150
Pout > 250 W N/A N/A N/A

External Ac-Dc Power Supplies

CUI is committed to implementing the latest energy saving technologies into our external power supplies to address increasing market demands and to comply with all current and future regulations. From late 2014, CUI began introducing a comprehensive DoE Level VI compliant adapter portfolio to keep our customers one step ahead of the rapidly evolving power landscape. Since then CUI has worked to ensure that the majority of its line of adapters not only meet DoE Level VI but also CoC Tier 2 standards.

pdf icon Read the Efficiency Standards for External Power Supplies Application Note.


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