Energy performance of external ac-dc and ac-ac power supplies

1.1 General 
This Standard specifies a test method for calculating the energy performance of external power supplies (EPS) across a full range of load conditions. It covers single-voltage and multiple-voltage external ac-dc and ac-ac power supplies. 

Note: External power supplies are designed to convert line voltage ac into the low-voltage output (ac or dc) typically required by laptop computers, cordless and cellular phones, portable stereos, etc. EPS are contained in a separate housing from the product they are powering. 

1.2 Purpose 
The test method specified in this Standard is intended to complement the methodology contained in CSA C381.2. This Standard and CSA C381.2 define two classifications of products for the purpose of energy-efficiency testing; products within the scope of CSA C381.2 are not intended to be tested by this Standard. Annex B provides information on determining the appropriate test method (this Standard or CSA C381.2) for measuring a product's energy efficiency. 

1.3 Exclusions 
The following are not covered by this Standard: 

a) Dc-dc voltage conversion equipment, such as dc-dc converters, are not included in this Standard, except to the extent that such circuitry is found within a power supply. 
b) A medical device as defined in Section 1 of the Canadian Medical Devices Regulations. 
c) A direct operation, ac-dc external power supply with nameplate output voltage less than 3 V and nameplate output current greater than or equal to 1,000 mA that charges the battery of a product that is fully or primarily motor operated are not covered by this Standard. 
d) Indirect operation non-Class A external power supplies. 

Note: These products may be covered by CSA C381.2. 

1.4 Terminology 
In this Standard, shall is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; should is used to express a recommendation or that which is advised but not required; and may is used to express an option or that which is permissible within the limits of the Standard. 

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. 

Notes to tables and figures are considered part of the table or figure and may be written as requirements. 

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.