MEPS Requirements for External Power Supplies

From 1st December 2008 in Australia and 1st April 2009 in New Zealand (see E3 notice of update to introduction date and scope - released 24 April 2008) most External Power Supplies with a nameplate output power rating up to 250 Watts, manufactured or imported for sale in Australia or New Zealand will be required to meet minimum energy performance requirements (MEPS). Introduction of MEPS is still subject to a regulatory impact statement and approval by the Ministerial Council on Energy.

Pre-registration is now available (from August 2008)(see making an application for MEPS for details).

The intention of MEPS is to increase energy efficiency by eliminating low efficiency external power supplies from the market and to encourage the use of high efficiency power supplies.

Products covered include external power supply units (often known as 'a.c. adaptors', 'plug packs' or 'power-packs') with a nominal 230 V a.c supply supply input and a single output at extra low voltage (ELV), either a.c. or d.c., and a maximum output of 250 W or 250 VA.

The units covered are not built into the equipment being powered and hence are 'external' to the device being powered. Designs covered include units with an integral mains plug, 'in-line' units and units with provision for equipment to sit in a cradle whilst being used.

A single output external power supply which is covered by MEPS is defined as a unit which:

has an input from mains supply (usually 110 V, 60 Hz; 230 V, 50 Hz; 240 V, 50 Hz or a range including some or all of these input conditions); and
has one ELV output (either a.c. or d.c.) that is either at a fixed voltage or user selectable through a selector switch; and
is sold with, or intended to be used with, a separate end-use product that constitutes the primary load; and
is contained in a separate physical enclosure from the end-use product (i.e. the housings of the power supply and its associated product are different, not their retail packaging); and
is connected to the end use product via a hard-wired or removable male/female electrical connection, cable, cord or other wiring; and
does not have batteries or battery packs that physically attach directly to the power supply unit (including those that are removable e.g. a battery pack for a portable electric drill); and
does not have a battery chemistry or type selector switch and an indicator light or state of charge meter.

The following flowchart can assist in determining if a power supply is covered by this Standard.

MEPS Levels

Energy performance requirements include the average efficiency (measured at 25%, 50%, 75% and 100% of rated output power) and consumption at no load. To meet MEPS, a power supply must meet or exceed the requirements for average efficiency, and meet or be lower than the no load thresholds, when tested according to AS/NZS 4665.1.

MEPS requirements are shown in Table 1 and Table 2 below:

Table 1: MEPS required minimum efficiency level

Nameplate Power Output (Pno)	Average Efficiency
0 to 1 watt	≥ 0.49 x Pno
> 1 to 49 watts	≥ 0.09Ln(Pno)+0.49
> 49 to 250 watts	≥ 0.84

Where:
Pno is the nameplate output power of the Unit Under Test.
"Ln" refers to the natural logarithm (base e). The algebraic order of operations requires that the natural logarithm calculation be performed first.

Table 2: MEPs required maximum no-load power (Watts)

Nameplate Power Output (Pno)	No Load Power Watts AC-DC	No Load Power Watts AC-AC
0 to < 10 watts	≤ 0.5	N/A
10 to 250 watts	≤ 0.75	N/A

High Efficiency Levels

Minimum efficiency levels for "High Efficiency Power Supplies", are shown in Table 3 below.

Table 3: Efficiency requirements for 'high efficiency' external power supplies

Nameplate Power Output (Pno)	Average Efficiency
0 to 1 watt	≥ 0.5 x Pno
> 1 to 51 watts	≥ 0.09Ln(Pno)+0.5
> 51 to 250 watts	≥ 0.85

Table 4: High Efficiency requirements for maximum no-load power (Watts)

Nameplate Power Output (Pno)	No Load Power Watts
0 to ≤ 250 watts	≤ 0.5

Energy Performance Mark

The energy performance mark is an international initiative to assist regulators monitor compliance with AS/NZS 4665-2005. It will be mandatory from October 2008.

Registration

Find out how to make an application for MEPS.

You can also download the External Power Supply Fact Sheet for more information on making an application.

This page last modified 15 August 2008